ML20197G967
| ML20197G967 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 06/30/1988 |
| From: | WESTON GEOPHYSICAL CORP. |
| To: | |
| Shared Package | |
| ML20197G964 | List: |
| References | |
| NUDOCS 8807120196 | |
| Download: ML20197G967 (156) | |
Text
O ANALYSES OF NORTHEASTERN OHIO SE!SMICITY AND TECTONICS Prepared for CLEVELAND ELECTRIC ILLUMINATING COMPANY O
JUNE 1988 g
4( h Weston Geophysical CORPORATION
- O 88 72= = = L P
t f-TABLE OF_ CONTENTS
(%)
Page LIST OF TABLES i
LIST OF FIGURES 11 1.0 EXECUTIVE
SUMMARY
l 1.1 Introduction and Studies 3
1.2 Summary of Studies 6
1.3 Report Preparation 11 2.0 GEOLOGY 13 2.1 Introduction 13 2.2 Precambrian Geology 13 2.3 Regional Palezoic Geology 15 2.4 Local Palezoic Geology 17 2.4.1 Structure Contours 19 2.5 Regional Analysis 22 2.6 Discussion 25 l
2.7 Pield Mapping - Lineaments 28 2.8 Conclusions - Geologic Investigations 30 i
l 2.9 References 32 3.0 GEOPHYSICS 36 3.1 Introduction 36 3.2 Interpretation 38 l
(
3.2.1 Regional Basement Framework 38
)
3.2.2 Eastern Midcontinent Magnetic Belt 42 l
3.2,3 Akron Magnetic Boundary 44 3.3 References 48 APPENDIX 3A DATA SOURCES. COMPILATION AND PROCESSING OF GEOPC7ENTIAL DATA 4.0 SEISMOLOGY 50 4.1 Introduction 50 4.1.1 Regional Seismicity 51 4.1.2 Correlation Between Magnetics and Se'.smicity 52 O
1993J l
Weston GeophWcol
TABLE OF CONTENTS (Cont'd)
Page f
4.2 Re-Evaluation of Specific Epicenters 53 4.2.1
.The 1983 Earthquake 54 4.2.2 The January 31, 1986 Earthquake 54 4.2.3 The December 3,1951 Earthquake 54 4.2.4 The May 26 and June 29, 1955 Earthquakes 58 4.2.5 The March 9, 1943 Earthquake 62 4.2.6 The Akron Earthquakes (1885. 1932. 1940) 63 4.3 General Discussion of the seismic Alignment 65 4.4 References 67
~
f n
l I
l l
l i
O 1993J i
l Weston Geochysco!
L
l l
I I
l LIST OF FIGURES IlO Tectonic Framework of the Grenville Province FIGURE 2.1 l
CALHIO Weli #1 Precambrian Core Description FIGURE 2.2 Generalized Stratigraphic Section for Ohio FIGURE 2.3 Composite Paleozoic Stratigra/;ic Section for Western New York FIGURE 2.4 l
FIGURE 2.5 Regional Tectonic Elements FIGURE 2.6 Well Locations FIGURE 2.7 Queenston Structure Contour Map FIGURE 2.8 Cross-Section A-A' Parallel to Strike FIGURE 2.9 Delaware Structure Contour Map 1:63.360 Packor Shell Structure Contour Map. Detailed Area FIGURE 2.10 1:63.360 FIGURE 2.11 Delaware Structure Contour Map. Detailed Area FIGURE 2.12 Well Locations. Detailed Area 1:63.360 FIGURE 2.13 Interpreted Lineaments and Field Reconnaissance Traverses Along AMB O
1993J wesion Gecphyscal
LIST OF PIGURES rfs k) s FIGURE 3.1 Composite Total Intensity Magnetic Anomaly Map FIGURE 3.2 Bandpass Filtered (20 - 40 km) Total Intensity
~
Magnetic Anomaly Map FIGURE 3.3 Composite Total Intensity Magnetic Anomaly Map FIGURE 3.4 Reduced to Pole Total Inter.sity Magnetic Anomaly Map FIGURE 3.5 Bouguer Gravity Anomaly Map FIGURE 3.6 Bandpass Filtered (20 - 40 km) Bouguer Gravity Map FIGURE 3.7 Reduced to Pole Total Intensity Magnetic Anomaly Map Upward continued to 2.0 km FIGURE 3.8 Reduced to Pole Total Intensity Magnetic Anomaly Map Upward continued to 5.0 km n
FIGURE 3.9 Vertical Derivative Reduced to Pole Total Intensity Magnetic Anomaly Map Upward continued to 5.0 km FIGUPE 3.10 Vertical Derivative Bouguer Gravity Anomaly Map Upward 4
T-Continued to 5.0 km s/
FIGURE 3.11 Internal Correspondence Analysis Correlation coefficient of Reduced to Pole Total Intensity Magnetic Anomaly and Vertical Derivative of Gravity Upward continued to 5.0 km FIGURE 3.12 Bandpass Filtered (20 - 40 km) Bouguer Gravity Anomaly Map FIGURE 3.13 Reduced to Pole Total Intensity Magnetic Anomaly Map with Interpreted EMMB Lineaments FIGURE 3.14 Bandpass Filtered (20 - 40 km) Bouguer Gravity Anomaly Map With Interpreted EMMB Lineaments FIGURR 3.15 Reduced to Pol.e Total Intensity Magnetic Anomaly Map with Interpreted EMMB Lineaments 1993J
(
t wevon Geophysical F
i LIST OF FIGURES FIGURE 4.1 Cumulative Seismicity M 21.0 Io 1 I (HM) 200-mile radius PNPP FIGURE 4.2 Cumulative seismicity M 1 1.0 Io E I (MM) 50-rtile radius pHPP FIGURE 4.3 Cumulative Seismicity and Reduced to Pole Magnetics -
f Northeastern Ohio area FIGURE 4.4 Felt Report Map-December 3. 1951 FIGURE 4.5 John Carroll Observatory Seismograms December 3. 1951 FIGURE 4.6 Felt Report Map-May 26, 1955 FIGURE 4.7 Felt Report Map-June 29. 1955 FIGURE 4,8 John Carroll Observatory Seismograms.
May 26. 1955 and June 29. 1955 Vertical Component FIGURE 4.9 John Carroll Observatory Seismograms.
May 26. 1955 and June 29, 1955 East-West Component FIGURE 4.10 John Carroll Observatory Seismograms.
May 26. 1955 and June 29. 1955.
North-South Component FIGURE 4.11 Weston Observatory. June 29. 1955 Seisir. grams lh 21m FIGURE 4.12 Weston Observatory. March 9. 1943 Seismograms -
Vertical Component O
1993J Wesbn Geophysical
1.0 EXECUTIVE
SUMMARY
(/
On January 22. 1988, the Ohio Citizens for Responsible Energy (OCRE) filed a petition pursuant to 10 CFR 2.206 requesting immediate suspension of the operating licerse for the Perry Nuclear Power Plant (PNPP) Unit 1 and the construction permit for Unit 2.
This request is founded upon an allegation that PNPP has an inadequate seismic design.
This allegation is based on hypothetical predictions in a report prepared by Yash P.
Aggarwal titled "Seismicity and Tectonic Structure in Northeastern Ohio:
Inplications for Earthquake Hazard to the Perry Nuclear Power Plant", hereafter referred to as the Aggarwal Report, and an accompanying affidavit by Aggarwal.
The predictions of the Aggarwal Report suggest that, based on a perceived alignment of historical earthquakes and a spatial correlation with intensity transitions in the Residual Total Magnetic Map of Ohio, a major fault or fault zone. extending 70 km in length, exists in the vicinity of PNPP which is capable of producing a magnitude 6.5 earthquake.
The V
Aggarwal affidavit states that a magnitude 6.5 earthquake in the vicinity of PHPP is "probable."
The petition concludes that the licensee.
Cleveland Electric Illuminating (CEI).
is not in compliance with 10 CFR 100. Appendix A which controls the NRC seismic analysis and design criteria for constructing nuclear facilities.
Specific studies conducted by CEI and their consultants were carried out over the last year.
These studies included detailed analysis along the Akron Magnetic Boundary (AMB) of the most recent (October 1987) geopotential data including gravity and magnetic anomaly maps, consideration of commercially available seismic reflection data near the AMB. additional geological investigations beyond the 1986 effort to characteri e the surface and upper crustal lineaments / features and a reexamination of historical events of interest to more definitively identify their uncertainty and possibility for being interrelated.
1993J
- 1*
Weston Geophyscol
The concensus of these reviews reaches a clear conclusion that there
'v' is no geoscience data or seismological data that supports the presence of a ~10 km long fault capable of producing a magnitude 6.5 earthquake, the January 31. 1986 5.0 earthquake, or other historical events identified by Aggarwal.
First. the location and associated uncertainty of historical events as documented in Appendix 2D-D of the Perry FSAR (1979) and in Ser: tion 2.5 of the Perry USAR (1988) are correct.
The relocation suggested by Aggarwal for the 1951 event cannot be reasonably supported.
The use of the joint epicentral determination for the 1943 earthquake proposed by Aggarwal is not feasible nor can the location uncertainties for the 1955, 1885 an( 1932 be reasonably reduced.
Second, af ter closely examining the aeromagnetic anomaly map of North America and its derivitives, it is concluded that the AMB does not represent a singular vertical discontinuity or fault.
By extrapolation into the Canadian Shield, the boundary consists of highly strained, ductilely deformed layered Precambrian rocks and represents the subcrop of a boundary of a more IAagnetic zone to the west overlain by a less Ox magnetic unit to the east.
The geological evidence illustrates that the 2 kilometers of Paleozoic sedimentary rock overlying the crystalline basement is relatively undisturbed with low relief foldir.g and possible minor offsets.
There is no evidence of multiple Paleozoic movements associated with reactivation as compared to a known faulted zone like the Clarendon-Linden in New York.
In limited northeastern Ohio outcrops, the predominant structures are joints with no concentration of northeast trends that might correspond to the AMB.
Imagery data spanning the AMB between Akron and Ashtabula do not reveal broad-scale lineaments associated with the AMB.
After reviewing the historical record and conducting additional I
geophysical analysis as recommended by Aggarwal. it is concluded that the earthquakes in northeast Ohio cannot be pcaitively correlated with any known fault.
The basic conclusions from all of this work support the previous licensing basis of a tectonic l
l J
1993J
- 2*
l l
Weston Geophysical L
A
(~'s province to select the safe shutdown earthquake characterized as a magnitude of 5.3 a r site intensity of VII cn the modified b
Mercalli Scale.
1.1 INTRODUCTION
TO STUDIES It is generally recognized in the scientific community that the 5.0),
which occurred January 31, 1986 Leroy earthquake (m
=
within 10 miles of the PNPP, is one of the most studied moderate magnitude events to occur in the eastern United States.
Immediately L
after the event. CE1 undertook a wide spectrum of geoscience and engineering studies to evaluate both the plant's response to this event and to study the geologic origin of the Leroy event.
Exhaustive studies were conducted in the immediate vicinity of the pl.cnt and the epicenter to reevaluate the geologic character of the region and its possible relationship with the earthquake.
These studies included extensive geological investigations of surface features via field mapping and examination of remote sensing imagery for potential fault related lineaments, contouring of key stratigraphic horizons from hundreds of geophysical well logs, and a complete review of new scientific literature associated with NE Ohio.
Also, additional geophysical field studies, including local high-resolution gravity and aeromagnetic surveys, were conducted to support analysis of the regional geophysical maps in an attempt to identify the existence of subsurface faults responsible for the i
Lastly, the complete seismic history for a radius of 50 miles from the plant was thoroughly re-examined, corrected and l
analyzed.
This documentation was assetabled into a comprehensive report and submitted to the NRC for review and examination in June 1986.
Subsequently, the NRC prepared a Supplemental Safety Evaluation Report (SSER No.
- 10) which concurred with the findings and the conclusions reached by CEI that there was no geological, geophysical, or seismological evidence to support the existence of a i
1993J
- 3*
Weston Geophyucal
.(
tectonic structure to which the Leroy earthquake coult be uniquely associated.
The licensing basis which established design criteria based on a tectonic province approach was reaffirmed, and the Leroy earthquake was recognized to be well within predictionr of earthquake magnitude for the province within which Perry resides.
To complete the record. Section 2.5 of the PNPP FSAR was updated, during the development of the Updated Safety Analysis Report (USAR),
with the current technical data.
Notwithstanding the effort expended by CEI and their consultants to produce the June 1986 Report and the USAR, another study was commissioned by CEI to evaluate the assertions in the Aggarwal Report.
Basically this study focused upon the Aggarwal Report recommendations which can be summarized as follows:
1.
The magnetic data for northeasterly Ohio should be reexamined l
in more detail, particularly north of the 1986 events.
O 2.
The structural geology along the aeromagnetic boundary should i
be reexamined more closely.
4 3.
High resolution seismic reflection profiles should be cmducted across the AMB boundary.
4.
Uncertainties in the location of earthquakec that occurred prior to 1980 in the vicinity of the AMB should be reduced.
All of the recommendations in the Aggarwal Report were considered and most were carried out.
For the surface geological studies two principal investigations were undertaken.
Imagery data, including satellite. SLAR. high-altitude color-infrared, and low-altitude black and white. spanning the AMB between Akron and Ashtabula were examined for lineament identification.
Field reconnaissance along interpreted trends was 1993J
- 4*
Wson Geophyscal J
f then conducted to ascertain if possible, the origin of these trends
\\
and evaluate their potential relationship with the AMB and regional seismicity.
In addition, subsurface geology was reevaluated by constructing contours of selected stratigraphic units within the Paleozoic section near the AMB in order to define the type and extent of deformation.
These contours were constructed from geopitysical well logs.
For the geopotential analysis and interpretation, five sets of gravity anomaly maps were processed and four sets of magnetic anomaly-maps were processed.
These data sets were edited for erroneous and redundant values, merged into a single data set, converted to rectangular coordinates, and interpolated on to a 2 km square grid.
Bouguer gravity and total intensity anomaly values were plotted for the entire study region at scales of 1:1.000.000 and 1:500.000, corrected and bandpass filtered to emphasize the anomalies and regional gradients. This data set was then correlated to available drill hole data, outcrop data in the Canadian Shield, and other recent interpretations in the literature.
Additionally, I
in tha area of the AMB in northeastern Ohio, seismic reflection data available from petroleum exploration and scientific studies by the consortium for contirental Reflection Profiling (COCORP) were integrated with the geopotential data to develop interpretative models.
Seismological studies imre focused upon reexamining the historical record for the 1986 1.eroy earthquake, two small events in 1983 north of 1.eroy. two 1955 Aurora earthquakes. two spatially related events in 1943 and 1951, and three historical events in 1940. 1932, and 1885 near Akron.
Uncertainties in location were confirmed by reexamining closely the seismograms and in some instances evaluating i
additional intensity report data.
in addition, the relationship of
[
these events to geopotential data were evaluated and the potential for interrelationships between events was explored.
O 1993J
- 5*
I L
Weston Geophysical
m
.__m
. y t
p The results of these three major independent studies leading to this D
conclusion are summarized in the following
- sections, which represents a
synthesis of the individual interpretations in geophysical, geological and seismological analysis.
i 1.2
.51MMARY OF STUDIES i
The regional and local areas surrounding the epicenter of the January 31, 1986 magnitude 5.0 m Leroy. Ohio earthquake were big thoroughly studied.
These studies included original work relative to gathering and analysis of new data as well as the reanalysis of existing geophysical, geological and seismological data.
GEOLOGY The overall pattern of sedimentation and subsequent deformation within the paleozoic section of northeastern Ohio is not significantly different than other regions within the designated Eastern Stable province.
Besides the typical northeast trending lithologic and structural grain prevalent east of the Grenville
{
Front. many northwest trending structures are reported in the region and occur. t,ased on present investigations. in northeastern Ohio.
The generally accepted interpretation of the earth's crust dissected by intersecting structural trends is appropriate for the province in general as well as the area of investigation in northeastern Ohio.
Seismic activity within the province is widely dispersed, forming clusters at certain points c.f intersection or along broad trends, which are favorably oriented or situated to accumulate and release moderate strain.
This type of localized moderate seismic activity.
[
typical of the eastern United States.
leaves little physical evidence such as recent offsets, brittle fractures, or accumulated
(
geomorphic indicators at or near the surface.
Extensive field mapping for this and previous investigations has verified the lack i
)
of such structure in the epicentral area and along the AMB.
- O 1993J
- 6*
f Weston Geophysical i
l
t
' Q Based on analyses of existing geological and geophysical data in northeastern Ohio, relative to the nature of the Akron Magnetic Boundary (AMB) a major ancestral geophysical feature proximal to the epicentral region, there is no compelling evidence to indicate that the AMB represents a unique or continuous seismogenic structure, several lines of evidence lead to this conclusion and support the maintenance of a province approach to licensing of the PNPP.
The AMB is likely characterized by a - broad ductile transition zone between contrasting Precambrian basement lithotectonic terranes.
Such boundaries are recognized in the Grenville Province exposed in Canada and can be extended beneath Paleozoic cover to the south utilizing gravity and aeromagnetic anomaly signatures.
Structural contour maps constructed from geophysical well logs, rather than seismic reflection profiling, were used to assess Paleozoic deformations because of better vertical resolution of that methodology.
sedimentation and erosion patterns. occurring within the overlying early to mid-Paleozoic rocks, are suggestive of a zone across which subsidence rates varied.
The zone roughly corresponds to the AMB: however, no fold or fault structures coincide with the AMB.
Further, based on recent deep seismic profiling data, the two kilometer thick Paleozoic section is essentially undeformed in the vicinity of the AMB.
This unconformable relationship between the Precambrian and overlying Cambrian sedimentary rocks show that the major tectonic activity which created the AMB ceased over 500 million years ago.
GEOPHYSICS Northeastern Ohio is transected by a boundary which is defined by a change in the magnetic anomaly pattern. West of this Akron Magnetic Boundary (AMB). the magnetic pattern is marked by relatively high intensity. high gradient. generally north to northeast striking 1993J e 7*
l Weston Geophysical
i anomalies.
The boundary is caused by a lithologic break in the basement rock which forms the eastern limit of a subterrane of the Central Metasedimentary Belt of the Grenville Province called the Eastern Midcontinent Magnetic Belt (EMMB).
This subtetrane extends from southern Ontario southward into Tennessee.
It was deformed, metamorphosed, intruded and uplifted during the 1.100 Ma old l
Grenville Orogeny.
Neither the gravity, aeromagnetic or the seismic reflection data indicate that the MB is a major high-angle discontinuity cutting the crust.
- Rather, geophysical evidence suggests that the subterrane is likely to continue at depth to the east of the AMB where basement is overlain by a more homogeneous. less magnetic granitic gneiss.
The nature of the contact between these units is 7
unknown.
It may be a stratigraphic or structural, but is likely on the basis of geological and geophysical evidence to be a low-angle thrust fault which steepens near the AMB and is not considered i
' e seismogenic.
Major lithologic variations occur within the EMMB subterrane west of the AMB. which generally parallel the AMB and are of the same nature as those occurring along the AMB.
The EMMB. which is province-like is identified on the basis of spatially consistent geophysical attributes which reflect regionally homogeneous 11thologies and geologic features.
i i
i The source of the anomalies west of the AMB are high-angle lithologic contacts which penetrate several kilometers from the i
basement surface into the crystalline crust.
These high-angle contacts may be caused by steep folds of varying 11thologic units.
faulting or locally by intrusions.
t In a regional context, the AMB and related anomalia of the EMMB are smoothly curving with two major bends in the northeastern ohic region, one in the vicinity of the southern 1.ake Erie shoreline and 1993J
- 8*
l t
Weston Geophysk;ol
4 another in east central Lake Erie.
In detail the AMB is complex.
consisting of many individual segments whose lengths are measured t
in a few tens of kilometers or less.
These segments are caused by northwesterly trending cross structures (probably faults).
Primary cross faults which transect the entire subterrane divide it into several discrete units that have minor lithologic characteristic variations.
Secondary cross faults of limited length are numerous and disrupt the continuity of the AMB and individual lithologic bands.
Where correlation to seismic data of sufficient depth exist in central chio the data are indicative of a highly contorted. intruded and metamorphosed basement rock between the AMB and the Grenville Front which is overlain by a relatively undisturbed Paleozoic sedimentary rock sequence.
These Paleozoic rocks have little effect on either the gravity or magnetic data.
SEISMOLOGY O
l Although previous work explored the potential correlation of earthquakes with local and regional faulting, the supposition ot a i
proposed spatial and causal relationship between northeastern Ohio 4
earthquakes and a 70 km long segment of the AMB. prompted additional 4
research reported herein.
l F
c The proposed alignment from north to south is made up of four sets of earthquakes:
1 1)
Two earthquakes in 1983 2) the 1986 Leroy earthquake the 1943 and 1951 events 3) two earthquakes that occurred in 1955, and 4) three events in the Akron area. in 1885. 1932, and 1940.
The epicenters, with location uncertainties as large as 10 miles, can be seen to form a NNE trending alignment, with an approximate 1993J
- 9*
Wevon Gecphyucol f
length of 70 km.
The more precisely located of these events, groups 1 and 2.
are in close geographic proximity.
Group 3.
the 1955 earthquakes, are located 40 km south southwest of Group 2. Group 4.
the smallest and most questionable of these events, are 30 km south southwest of Group 3.
In summary the farther the alignment extends to the south, the weaker it bacones due to the distance between events, their size and the suspect quality of the data set.
These earthquakes span a long time period:
from 1885 to 1986.
As such, some have large location uncertainties, and except for the more recent ones, post 1980. have locations generally dependent on felt reports.
Felt reports are of ten affected by subjectivity in reporting intensity values, soil amplification, spatial extent of the territory canvassed. etc.
These earthquakes vary greatly in size from magnitude 2.3 (1983). to 5.0 (1986). and from intensity II for the 1940 Akron tremor. to intensity VI for the Leroy 1986 earthquake.
In summary. the proposed soismic alignment is based on a data set that is rather i.nhomogeneous in quality.
The earthquakes at the northern end of the alignment, such as the 1983 and 1986 earthquakes are the most reliable ones, being supported by instrumental data.
The 1978 relocationing of the 1943 event is also based on instrumentat data, although less reliable.
The 14 km uncertainty that was attached to this relocation (Dewey and Gordon.
1978) will not likely be reduced, since a joint epicentral determination does not appear possible, the majority of the stations that recorded it in 1943 having been closed prior to the Leroy earthquake occurrence.
An estimated magnitude of 4.5 was confirmed from Lg amplitudes and from observed instrumental duraticns.
The December 3.
1951 event. originally placed near Willoughby, on the basis of felt reports and one (S-P) interval as recorded at John Carroll Observatory, possibly could be relocated closer to the Mentor area.
An offshore epicenter is equally realistic and would 1993J
- 10
- Weston Geophyucol
m rs explain the observed felt data.
The magnitude of this event seems smaller (2.6) from the John Carroll seismograms than previously estimated (3.2) from felt area.
The reevaluation of felt reports data and some seismograms of the two 1955 earthquakes confirms the previous previous relocation from downtown Cleveland to the area northwest of Aurora, 40 km south southwest of the 1986 1.eroy earthquake.
Because of the poor quality of photographic recordings used to calculate the epicentral distance, an epicentral uncertainty of 10 miles remains prudent.
The June 29 event now appears to be larger than the May 26, 1955 event; magnitudes of 3.6 and 3.4.
an.? intensities I, of IV-V and IV respectively, are now suggested.
The earthquakes in the vicinity of Akron, almost 30 km south of Aurora, represent the weakest data along the proposed 70 km seismic alignment.
Two of these events. 1932 and 1940, with intensity IV and 11 respectively, have been felt in a very restricted area.
The January 18, 1885 event has been and continues to be a mysterious event, and could possibly be a frost quake.
In summary, from the seismology viewpoint. the proposed 70 km long seismic alignment must remain speculative since the quality and I
significance of each of the four groups of earthquakes decreases from north to south.
1.3 Report Preparation The reports comprising sections 2.0 Geology, 3.0 Geophysics, and 4.0 Seismology, stand as individual documents prepared by Weston Geophysical and Dr. William Hinze for this submittal.
In response to Aggarwal's Recommendation 1.
CEI contracted the servi:es of Dr. William Hinze from Purdue University's Department of Geophysics.
Dr.
H1'ize was responsible for analysis of the geophysical data and preparation of the Geophysics section (3.0),
1993J
- 11
- Weston Geophyuco!
In response to Recommendations 2 and 4 CEI utilized the services of
(-
N Weston Geophysical. specifically. Preston Turner. Project Geologist, and Jim Rice.
Geologist for the Geology section (2.0);
and Dr. Gabriel Leblanc.
Senior seismologist acting as Project seismologist for the seismology section (4.0).
The Introduction and summary section of the report was jointly produced by the scientists involved under the direction of CEI and reviewed by Richard J. Holt.
Senior Scientist acting as Project Consultant and Edward N. Levine.
Project Manager.
O O
1993J
- 12
- Wdor. Geophysical
2.0 GEOLOGY o
2.1 Introduction The geologic and structural framework of northeastern Ohio and adjacent regions results from an ancient and complex continental I
margin accretion and tectonism followed by a more quiescent continental platform and basin margin sedimentary and erosional sequence.
Recorded in the Precambrian basement is a large-scale northwest-directed collision and transport of a
series of lithotectonic belts which comprise the northeast-trending Grenville Province.
Sedimentary shales, sandstones. limestones and salts, overlying the deeply eroded basement, fill the northeast-trending Appalachian Basin.
The northwestern flank of the Appalachian Basin, defined by the Ohio-Indiana-Algonquin platform, is characterized by diminishing structural deformation at the limits of the effects of the Appalachian orogeny.
The gently southeast dipping Paleozoic beds are locally disrupted by compressional thrust faults and folds.
i local reactivated basement
- faults, and penecontemporaneous deformations.
The present landscape, produced by erosion of the youngest upper Paleozoic units, has been modified by Pleistocene glaciation with its associated till sheets and glaciofluvial t
deposits.
2.2 Precambrian GeoloqY p
h' The Precambrian basement beneath the 2 km thick Paleozoic section in i
northeastern Ohio is part of a deeply eroded remnant of a broad compressional belt.
the Grenville Province, formed about 1 Ga between the North American craton and a continental basement to the southeast.
On the northwestern margin of the province.
the Grenville Front shows substantial evidence of sautheast over northwest transport along a wide, southeasterly dipping structural t
zone.
To the southeast, a series of terranes are recognized comprising the Grenville Province (Figure 2,1).
The boundaries of i
1993J
- 13
- g i
WWon Geophyacol
l A
these terranes, characterized by ductile shear zones in the Canadian d
Shield, also show predominant southeast over northwest transport.
The intensity and broad scale nature of the low-angle deformational fabrics suggests substantial shortening and stacking of lithotectonic slices, resulting from a "Himalayan-type" collision.
The specific terrane of the Grenville Province mapped in Canada which lies on strike with northeastern Ohio is the Central Metasedimentary Belt (CMB). comprised of a sequence of supractustal metasedimentary and metavolcanic rocks deposited on older basement.
These rocks, which are not widely distributed in the Grenville Province, are interpreted to have formed along an ocean margin or in an intracratonic rif t (Moore. 1986).
Subdivisions of the CMB are recognized. including the Bancroft and E12evir terranes.
- Locally, less intense deformational fabrics permit local stratigraphic subdivision of the Elzevir. which cannot, however, be traced into adjacent terranes.
Recognition and extrapolation of the sub-terranes comprising the CMB are supported by interpretation of the associated aeromagnetic and gravity data (Forsyth et al.
1988).
Characteristic geophysical j
anomaly patterns extend southwestward beneath the Paleozoic cover into southwestern Ontario and northern Pennsylnnia and Ohio.
This information combined with limited crystalline rock data from deep wells provides a basis for inferring possible Precambrian lithologic and structural features in northeastern Ohio.
l The boundary between the Elzevir and Bancroft terranes is most readily traced by aeromagnetic signature southwestward from the j
Canadian Shield into nottheastern Ohio.
While the boundary is l
traceable. the terrane to the northwest of the boundary changes magnet.ic character.
This newly recognized Eastern Mideontinent Magnetic Belt (EMMd) terrane replaces the Central Gneiss Belt.
Both terranes are lens-shaped and pinch out against the Grenville Front.
l This occlusion of terranes against the northwestern boundary of the f
1993J e 14
- i Wevon Geophyacol
Grenville Province is recognized in Canada, suggesting an oblique 7xj collision during the Grenville orogeny at some angle to the Grenville Front (Davidson, 1986).
An allochthonous origin for these terranes is suggested by the lack of correlation of the aeromagnetic (shallow) anomaly pattern and the gravity (deep) anomalies as well as geologic evidence.
l Within the EMMB, drill data indicate that the Precambrian basement is comprised of medium to high-grade metamorphic granite gneiss.
syenite
- gneiss, granodiorite
- gneiss, gabbro.
schist and metasedimentary rocks (Lucius, 1985: Turek and Robinson, 1982:
Gonterman, 1973).
Examination of 10.5 feet of Precambrian core from the CALHIo #1 well in Perry. Ohio revealed a very fine-grained dark green schist, apparently intruded by a very fine-grained medium gray weakly foliated diorite (Figure 2.2).
A mylonitic fabric is apparent in a ductile shear zone and flattened potassium feldspar grains paralleling the shallow (30*) dipping metamorphic foliation
(]
in the schist.
Weathering related alteration of the recovered interval includes hematite replacement and dolomitization of the diorite.
Weathering effects are frequently cited as diminishing the confidence in assessing Precambrian basement lithology from relatively shaliow core penetrations.
The linear high-amplitude aeromagnetic anomalies of the EMMB suggest across strike lithologic variations, possibly resulting from tight folding or thrust stacking.
The intensity of these linear anomalies increases approaching the AMB, which marks the boundary against a low-gradient aeromagnetic anomaly pattern to the southeast.
Very limited drill hole data southeast of the AMB indicates that the Precambrian basement is primarily granite gneiss in this area.
[<esional Pa_leozoie Geology 2.3 e
A transgressive marine sequence of coarse marine sandstones was initially deposited on the deeply eroded, subsiding Grenville
()
landmass in upper Cambrian time.
This was followed by deeper water 1993J
- 15 +
mson Gnph,9:01
e dolomites.
limestones, and shales as the continental margin
\\
'sj subsided.
Normal faults were active at this time, stepping down to the southeast (Beardsley and Cable. 1983).
Thicker sediments were deposited in the more rapidly subsiding Rome trough.
Tectonic uplif t and rejuvenation associated with continental collision to the east provided a new source of sediments which eccumulated in the adjacent Appalachian basin.
Periodic uplif t and subsidence of the basin controlled a
series of transgressive and regressive sedimentary sequences interspersed with erosional unconformities.
This thick sequence forms the mildly deformed Paleozoic sedimentary cover which outcrops throughout the region.
Figures 2.3 and 2.4 show typical stratigraphic sequences for Attica, New York and Ohio, indicating the continuity of the recognized sedimentary sequence over a wide region.
Several distinct styles of structural deformation occur within the Paleozele sedimentary rocks of the Alleghany Plateau (Figure 2.5).
(^')
Approaching the northwestern limits of the influence of the A11eghanian orogeny in central Pennsylvania, decollement offsets and fold amplitudes diminish.
Terminal structures such as the Burning Springs anticline in West Virginia and the Bass Islands trend in western New York occur where horizontal decollement surfaces are ramped up into overlyira sedimentary rocks coincident with the termination of ductile glide surfaces such as salt horizons.
The resulting barrier to further northwestward translation forced the decollement surface upward into overlying sediments creating an imbricate thrust stack and associated anticlinal bulge.
Vertical tear faults oriented perpendicular to the thrust f aults bound the margins of individual thrusted blocks cornpensating for dif ferential movement around the curved margin of the Appalachian Basin.
Reactivated Precambrian structures are revealed by seismic and drill data.
Normal faults step down southeastward into the axis of the Appalachian Basin (Beardsley and Cable. 1983).
A more significant
( )
deformation is represented by the Rome
- trough, a
linear 1993J
- 16
- wmn Geophoca'
fault-bounded graben trending from Kentucky northeastward across b
central Pennsylvania into New York.
These structures were primarily active as grwth faults during early basin subsidence.
As the Appalachian Basin
- filled, gradually diminishing deformation is
-recorded in
- local, abrupt linear sediment facies variations associated with the buried Precambrian structures.
Other indications of Paleozoic deformation associated with I
reactivated Precambrian structures are noted.
For example, the eastern margin of the Elzevir terrane and a regional mylonite belt within the eastern E12evir can be traced in the aeromagnetic data southward beneath the Paleozoic cover connecting into the Clarendon-1.inden fault zone (Figure 2.5).
The Clarendon-1.inden structure in western New York state is characterized by several high-angle faults which offset Cambrian through 1.ower silurian sedimentary rocks, with maximum reported cffset of 100 meters (Van Tyne. 1975).
The fault zone extends 100 kilometers between Murray and Pike. New York. based on seismic reflection and drill hole data.
A central fault zone, approximately 2 km wide, is comprised of two principal faults dipping slightly east, which define a i
central horst, with rock units relatively down to the east and west l
(Pomeroy et al. 1979).
Van Tyne (1975) also recognized two other l
faults bracketing the central fault zone. with offsets significantly l
1ess than the resolution (25-30 meters) of the reflection technique utilized in Pomeroy's investigation.
2.4 1.ocal Paleozoic Geoloqv In order to assess the nature and extent of Paleozoic structural deformation in northeastern Ohio, two methods. seismic reflection and structure contouring from geophysical logs were considered.
To provide the greatest amount of vertical resolution of Paleozoic structures in the vicinity of the AMB.
We chose structural contouring of Paleozoic marker horizons identified on geophysical logs of boreholes drilled for petroleum exploration activities in 1993J
- 17
- WWon Geophysco!
northeastern Ohio (Figure 2.6).
Although the resolution of individual marker beds on geophysical logs is less than one meter.
the accuracy of the elevations of the marker beds, as used to create contour maps, is dependant on the accuracy of the surface reference e)evation.
The surface reference elevations are generally measured by a registered surveyor, llowever, estimates of ground elevation from topographic maps with a contour interval of 3.5 meters are sometimes used when survey data are not available.
This estimation e
of ground elevation, along with estimates of the ground level to reference point height, results in a maximum potential deviation of 3.5 meters.
The use of high resolution seismic reflection data was considered and rejected because of inadequate vertical resolution.
Samples of proprietary seisnic reflection data ocquired in association with oil and gas exploration activities were examined.
The dominant period of the shallow reflectors observed on the data samples is around 20 msec. giving a wavelength of about 120 meters if the velocity is 4.000 m/sec (the value used by Geodata for their datum correction).
In this zone the smallest vertical offset which could be resolved is one half wavelength, approximately 60 meters.
The width of the Fresnel zone at 1 see time is approximately 300 meters.
Sudden off sets would therefore tend to be smeared out over this horizontal distance.
None of the sample weismic recordings of proprietory data made available for our review included a continuous section across the MB. nor does there appear to be a complete section or profile available in the area north of Coshocton County in east central Ohio, based on our inventory of proprietary data.
Neither Beardsley and Cable's (1983)
~l kilceeter profile in Coshocton County or the COCORP line across Ohio show any indication of a
vertical displacement in the Paleozoic section in the vicinity of the MD within the vertical resolution capabilities of the seismic s
1993J
- 18
- wen Gxpre,9co'
q reflection data.
Between the Grenville Front and eastern Ohio the
~
COCORP data describes a smooth and gently dipping Precambrian basement surface.
2.4.1 ptructure contours Analysis of structural and isopach contour maps of Pileozoic units was used to assess structural deformation and stratigraphic relationships on a regional and detailed scale in northeast Ohio.
Features observed in Paleozoic rocks include penecontemporaneous j
- erosion, differential ccepaction, tectonic basin subsidence.
compressional folding. localized fault offsets, organic carbonate build-ups and salt dissolution.
These deformational features were observed in strata ranging in age from Cambrian through Devonian.
Local disruptions of the overall regional dip of the Paleozoic units into the Appalachian basin include domes. depressions, anticlines.
and structural noses (Gray et al. 1982).
The majority of these features are not of regional significance in contrast to, for example.
the Clarendon-Linden or Rome trough structures.
A l
relatively simple structural configuration on the northwestern margin of the Appalachian Basin is apparent even in the vicinity of the AMB.
Two regional erosional / depositional features are observed in northeast Ohio that appear to be spacially coincident with the AMB.
The western subcrop limits of the Late Cambrian Rose Run Sandstone and the Devonian Criskany Sandstone are roughly coincident with the AMB.
Structural and stratigraphic analysis of the Rose Run Sandstone indicates that it was deposited in a marine environment and its depositional limit was located just west of its present subcrop limit.
Subsequent erosion associated with the Knox Unconfermity in Late Cambrian to Middle ordovician time moved the western boundary of the Rose Run to its present subcrop position.
Detailed stratigraphic analysis of the units immediately overlying 1993J
- 19 e We90r Geophyxor
and undierlying the Rose Run indicates an increase in preservation of younger units overlying the Rose Run along the northeast trend. most likely caused by depositional thickenifig associated with variation in rates of basin subsidence.
The Devonian Oriskany Sandstone is also bounded by an unconformity and its subcrop pattern is most likely controlled by similar basin margin tectonics (Meki. 1986).
In &ddition to the larger scale regional trends, a significant nu:aber of small-reale features are observed in northeast Ohio and adjacent areas.
McMul' 6 476) and Pees (1986) describe the top of 1 Shale in Ashtabula county and adjacent the Late Ordovician Qu-A irrie and crawford co-'
..s.
Pennsylvania as a horizon at which deeper deformation is expressed.
Typical featurer observed on the Queenston Shale include noses, benches, saddles and locally. limited faulting.
Structure contour maps prepared for is report support these observations (Figure 2.7).
In east-central Ashtabula county a series of broad north-south anticlinal folds are observed.
These folds range in length from 10 to 25 kilometers and obtain a maximum relief of 16 meters over 3 kilometers.
The folds propagate through the stratigraphic sectim.
but become less prominent on the Delaware Limestone contour map due to the effects of the intervening Salina salt.
They are also observed on cross section A-A' (Figure 2.8).
The folds are most likely due to regional deformational events associated with basin development based on their orientation and linear extent.
Features on the top of the Devonian Delaware Limestone appear to be more subtle due to the influence of
'.h e Silurian Salina salts immediately below the Delaware which glow plastica 11y and absorb deformation (Figure 2.9).
In addition to the more subtle contour patterns. the influence of the salts can be observed in Ashtabula county as anomalous high and low areas.
Dissolution of salt layers.
l creating depressions and dip reversals, was enhanced by fractures 1993J e 20 *
- v. won Geophyscal
___ _, - _.. _ ~. _ -.. _,... _.
associated with sediment loading of the basin.
Similar structures p
(/
are observed on contour maps of the same unit in the Canadian portion of Lake Erie (Ontario Geological Survey, 1985).
A more detailed study of the Paleozoic structural configuration was conducted for a small area of Lake County between Lake Brie and the Grand River including Perry and Leroy Townships.
Analysis of the contour maps indicates the presence of two sets of low-amplitude tight folds which plunge to the southwest and southeast and appear to die out to the north.
The patterns are observed on all stratigraphic levels contoured, however, they are very subtle on the Delaware due to the intervening salts (Figures 2.10, 2.11, 2.12.).
The large number of closely spaced well control points allowed detailed contour patterns to be drawn in the Perry /Leroy area.
Previous interpretation with less well control available, indicated broad, laterally extensive folds and discrete structural highs in this area (Weston, 1986).
clearly, the supplemental data indicate V
localized deformation defined by the closely spaced control.
Other studies of these formations in northeast Ohio which employ similar data density show numerous small structural features of similar orientation (Knight, 1969: McMullin, 1976: Santini and Coogan, 1983:
Coogan, 1987).
Based on the structural and isopach contour maps prepared for this study and those contained in the available literature, the Paleozoic rocks in northeast Ohio appear to be mildly deformed as evidenced by small-scale depositional and compressional features.
Our analysis indicates that no major, through-going vertical structural features are associated with the AMB er occur within any part of our area of analysis which includes Lake, Geauga and Ashtabula counties.
It is equivocal whether the small-scale features observed are either folds or small faults of limited horizontal extent with cumulative vertical displacements not exceeding 16 meters.
Some of these features may be related to differential basin subsidence along a 1993J
- 21
- Weston Geophysical
boundary roughly corresponding with the AMB.
Similar boundaries are present in the Appalachian Basin area and exhibit similar lithofacies relationships (Root, 1978; Rogers and Anderson, 1984).
The presence of these boundaries was postulated by Beardsley and Cable (1983) throughout the Appalachhan Basin as representing reactivation of Grenvillian zones of weakness (thrust faults) during early Paleozoic subsidence in a tensional stress environment.
2.5 Regional Analysis Besides the typical northeast-trending structural trend paralleling the Precambrian fabric, cross-cutting northwest and north-south trends also occur.
From previous investigations the most significant of these structures in northeastern Ohio, a series of en echelon fault zones, extending from Columbiana County northwestward to Cleveland, are mapped on the Berea Sandstone and onondaga Limestone (Figure 2.5).
From northwest to southeast, the Middleburg, Akron, Saf field, Smith Township, and Highlandtown f aults range from 16 - 30 kilometers in length.
The fault zones are typically 1.5 to 3 kilometers wide, arranged in an en echelon pattern that indicates a common or continuous structural feature at depth in the Precambrian basement.
Precambrian strike-slip of fset interpreted from the magnetic anomaly pattaen was followed by vertical reactivation cutting the Paleozoic sedimentary rocks with an interpreted maximum of 80 meters of offset up to the northeast (Gray et al, 1982).
This feature, apparent in offset magnetic anomalies, cuts the AMB and has been suggested to represent a northwestward extension of the so-called Latitude 40' or Transylvania fault in Pennsylvania (Root et al, 1977; Root and Hoskins, 1977).
A potentially more valid correlation is provided by the pittsburg-Washington lineament which these faults bracket.
While the prominent lithostructurel fabric in the Grenville Province trends north-south to northeast, examination of various geological r
and geophysical data also reveals evidence of northwest-trending 1993J
- 22
- Weston Geophysical l
L*Wmpgn:y patterns cross-cutting and locally offsetting the Precambrian q
V fabric.
Northwast-trending structures have been interpreted from gravity an:_ aeromagnetic data, remote sensing imagery, and geologic mapping of brittle structures in the Paleozoic cover rocks (Figure 2.5).
Two broad-scale lineaments have been reported in recent literature, the Pittsburgh-Washington and the Tyrone-Mount Union lineaments.
Of the two, the Tyrone-Mount Union has been supported by several lines of evidence which together suggest a Precambrian crustal structure reactivated during the Paleozoic, and locally producing brittle joints, fracture zones, and faults cutting the Paleozoic sediments.
Observed offsets of the aeremagnetic and gravity anomaly trends indicate 60 km of right-lateral motion of Precambrian lithologic belts, over a total length of 400 km from the Atlantic coast to Lake Erie.
Terminations and deflections of Paleozoic folds and faults are also noted coincident with the feature (Lavin et al,
/7 1982).
Local concentrations of brittle structures, particularly b
joints and fractures, above regional background frequencies show indications of enhanced hydrocarbon release (Rodgers and Anderson, 1984).
Local facies changes reported in wells penetrating ordovician and Silurian sedimentary
- rocks, suggest anomalous paleo-bottom topography coincident with the alignment.
Base-metal sulfide veins associated with enhanced fracture intensities are in part responsible for observed lineaments.
The subparallel Pittsburg-Washington lineament is drawr. f rom several lines of evidence.
From the geophysical data, a steep magnetic l
gradient corresponds to the lineament ir: southwestern Pennsylvania south of Pittsburg.
Gravity anomalies are also disrupted indicating a significant basement geological discontinuity.
To the southeast in Maryland. Virginia, and Western Virginia, similar magnetic and gravity patterns and terminations and a linear segment of the l
Potomac Vall.ey are noted.
Northwestward into
- Ohio, the l
N
/
Pittsburg-Vashington lineament is bracketed by the Paleozoic I
1993J
- 23
- Westca Gec@ysical
Middleburg, Akron, Suffield, Smith Township, and Highlandtown faults m
(Figure 2.5).
This section of the lineament traces the northeast flank of a
broad gravity high and cuts the prominent nottheast-trending magnetic anomaly pattern of the AMB and EMMB.
Subparallel northwest-trending lineaments and fabrics betw?en the Tyrone-Mount Union and Pittsburg-Washington trends have been reported.
These features, for example the Wagner-Lytle lines, are obviously less significant in scale but are evident as cross-strike lineaments, terminations and deflections of Appalachian structural trends, and discontinuities in the geophysical data.
Wagner-Lytle lines (Briggs and Kohl, 1976) are described as diffuse fracture zones, more numerous than typical fracture and joint intensity levels.
The saore prominent occurrences in western Pennsylvania are also characterized by local disruptions of the northeast-trending Appalachian fold axes.
Analyses of the Earth Resources Technology Satellite imagery in northeastern Ohio and northwestern Pennsylvania reveal a potential correlation of northwest-trending lineaments and extensions of the Wagner-Lytle line trends (CEI FSAR, 1979).
Extrapolation of these trends to the AMB and northwestward is compatible with the evidence of northwest cross-trends in the aeromagnetic map, particularly in the EMMB. This suggests the existence of periodically reactivated brittle structures which segment the AMB and the EMMB into distinct crustal units of various scale.
In southwestern Ontario structural contour maps of units within the Paleozoic section show an intersecting fracture pattern which has been related to periodic basin and arch adjustments during the Paleozoic (Sanford et al, 1985).
The interpreted pattern, which is more complex than that to the southwest in the Appalachian basin, is marked by two distinct fracture patterns, separated by the Algonquin Arch and Chatham sag.
The intersecting fractures reacted to basin and arch vertical movements by minor tilting and adjustment.
The i
1993J
- 24
- Weston Geophysical 1
occurrence of structural traps, fractured dolomitized zones, salt
.j. n) dissolution structures and related sedimentologic traps such as patch and pinnacle reefs, is related to oil and gas producing zones in the region.
Comparison of the fracture pattern with recorded seismic activity (Figure 2.5) reveals coincidence of increased or concentrated fracture densities and intersections with clusters or alignments of activity.
Joints are the predominant structures which occur throughout the basin.
These features are apparently the result of stress during basin subsidence and sediment compaction as well as uplift and erosion.
Joint trends parallel and perpendicular to the A11eghanian structural front (Figure 2.5) are apparently controlled by the compressional event, either during hydrofracturing associated with burial and compaction, or tensional cracking upon uplift and removal of overburden load.
A secondary joint orientation with a consistent east northeast trend throughout the region may be the result of tensional forces perpendicular to the present day stress field V
oriented east-west to northeast (Engelder, 1982).
The consistent regional pattern and relatively uniform distribution of these joint types is maintained in northeastern Ohio showing no correlation with interpreted Precambrian trends.
Their occurrence is distinct from more localized, concentrated linear fracture zones such as those reported along the Tyrone-Mt. Union lineament, which are attributed to reactivation of buried Precambrian structures.
Extensive remote imagery interpretation and field mapping in the 1986 epicentral area and along the AMB have revealed no consistent or anomalously intense fracture concentrations that might be related to significant Precambrian structure.
2.6 Discussion i
The preceeding sections contain descriptions of the consistent l
O lithologic and structural framework which supports the designation b
1993J
- 25
- Westor, Geophysicci
of the province incorporating the PNPP site.
Although covered by a
'~'
variably thick sequence of relatively undeformed Paleozoic sedimentary rocks, the Precambrian basement lithology and structure are important because the significant seismic activity within the province originates from such structures at depth beneath the Precambrian unconformity.
A reasonable description of the Precambrian basement has been presented, based on seismic reflection data, basement drill hole lithologies, extrapolation of geopotential data frcm Grenville outcrop in Canada, and geophysical modelling.
These structural interpretations are supported and extended to some degree by an understanding of str uctures occurring within the Paleozoic section.
Comparison and contrast of the Precambrian structures and the occurrence or lack of related seismic activity allows for an assessment of the seismic events in northeastern Ohio in the context of activity throughout the province.
The one recognized correlation of seismicity with a known structure OQ in the province occurs along the Clarendon-Linden fault zone.
This correlation has been made based on the weight of evidence which includes well estabitched faulting of the Paleozoic section, induced seismicity in the vicinity of one of the faults, and interpretation of associated Precambrian structures from gravity and magnetic l
data.
Such specific correlation of seismicity with the Clarendon-Linden structure is arguable, based on the occurrence of a larger band of seismic activity, incorporating the Attica event, trending westward from the Clarendon-Linden to the Niagara peninsula.
As is the case in northeastern Ohio, an apparent north-northeast spatial alignment of geological, geophysical and seismic activity patterns is cut by a more subtle northwest alignments.
Comparison of the Clarendon-Linden structure with potential structures elsewhere in the province and particularly in northeastern Ohio shows that the Clarendon-Linden is only unique in v
terms of the scale of Paleozoic deformation and the association of 1993J
- 26
- Weston GeophysCol
_(]
induced seismicity with interpreted faults in the subsurface.
U Although reasonable, it is not certain that the historical events, including the 1929 Attica event, occurred on related north-northeast trending faults in the Precambrian basement.
The possibility of northwest-trending structures, indicated by disruptions of geophysical anomalies, cannot be ruled out and such orientations are the natural complement of north-northeast focal plane solutions determined for past events (Hermann, 1978).
Correlation of the Y~
scale of the Paleozoic structures with potential earthquake magnitude is also not strictly valid because other factors are important, particularly orientation of the structure in the existing stress field.
For example, the structures comprising the Rome
- trough, a
fault-bound 2d graben are much larger than the l
Clarendon-Linden style deformations.
Apparently def,rmation along this structure diminished relatively early in the history of the Appalachian basin and its orientation subparallel to the existing stress regime is presently unfavorable for stress accumulation and release.
Locally interpreted fault splays off the main structure, in the area of the Kentucky River fault, have been active, and were apparently responsible for the 1980 Sharpsburg, Kentucky event.
Correlation of the seismic activity in northeastern Ohio with specific brittle structures is difficult.
Precambrian basement structures at epicentral depths are likely ductile in nature and while geopotential anomaly patterns are indicative of their spatial distribution, no evidence for the extent of brittle faulting in the Precambrian associated with the ductile boundaries is available.
In contrast to the Clarendon-Linden fault zone with well-defined Paleozoic faulting, structural contour maps of the Paleozoic section in northeastern Ohio show only minor folds and faults which occur with varying intensity throughout the region and are not unique to the AMB.
Northwest-trending fracture zones cut the regional Grenville lithotectonic
- fabric, limiting the AMa's effective length.
A few of these interpreted boundaries and intersecting structural zones may be active as they adjust in the prevailing 1993J
- 27
- Weston Geophy9 Col
-n stress field.
The evidence for multiple trends in the geologic, geophysical and seismological data of northeastern Ohio indicate that the AMB is not a continuous r:eismogenic structure.
L 2.7 Field Mapping - Lineaments l
Imagery
- data, including satellite.
- SLAR, high-altitude color-infrared, and low-altitude black and white, spanning the AMB between Akron and Ashtabula. Ohio, show several linear features, a small portion of which are subparallel to the AMB.
Broad-scale lineaments interpreted from the high-altitude. SLAR, and satellite images have been previously discussed (Cleveland Electric Illuminating, 1979).
The majority of these lineaments correlate with broad surficial features, including stream channels, beach strandlines, and glacial moraines.
In
- contrast, several northwest-trending lineaments are on-trend extensions of interpreted fracture zones in western Pennsylvania, reported by Wagner and Lytle (1976).
- However, no actual fractures corresponding to these particular lineaments have been mapped in northeastern Ohio due to the lack of outcrop in the region.
The present photo interpretation investigation was undertaken as a preliminary step prior to field checking of several linear featurea noted trending subparallel to the AMB (Figure 2.13).
Field reconnaissance along the interpreted trends has shown no observed bedrock structures correlative with the lineaments.
In limited
- outcrops, located principally in stream
- cuts, the l
predominant structures are joints.
These vary considerably in i
length and width.
The majority are tight. typically several meters to tens of meters in length, with the largest observed being several 100 meters long and approximately 0.5 meters wide, occurring in a sandstone quarry in Bainbridge, Ohio.
Joint orientations are generally northwest and northeast corresponding to the recognized CJ 1993J
- 28
- Weston Geophysical
north-south and east-west trends.
No particular concentration of V
northeast or north-northeast trends were noted that might correspond to the AMB trend.
A circular drainage pattern, approximately 4 kilometers in diameter, located in Bainbridge, Ohio observed on several imagery types was also checked in the field.
No structural control of this feature, such radial or curvilinear fracture patterns was observed.
Several of the lineaments observed on the color infrared imagery, particularly concentrated between Bainbr.tdge and Newbury, correlate with slightly depressed drainage swales in the surficial deposits:
mainly ground moraine.
Bedrock control of such features is possible but it is more likely that the drainage pattern originated along linear topographic irregularities in surficial deposits adjacent to downwasting and locally isolated ice masses.
3 The linear features noted in Aggarwal (1987) were examined in the (G
aerial imagery as well.
Several stream alignments, particularly in the area of Bass Lake and southwest of Chardon, Ohio, were checked during the field reconnaissance.
Here again the limited available outcrop showed no structures other than the typical regional joint trends.
The general lack of structures at the surface which might originate from tectonic structures at depth in the Precambrian, is consistent with previous reports of investigations in the area (Weston Geophysical, 1986).
The thick Paleozoic section presumably absorbed penecontemporaneous and later Appalachian basin deformations which are on the order of tens of feet at a depth of several thousand feet.
Subsequent strike-slip reactivation (based on fault plane solutions) of brittle Precambrian basement faults in a localized intersection environment would likely produce little deformation in the overlying Paleozoic section.
OG 1993J
- 29 +
Weston Geophysical
2.8 conclusions - Geologic Investigations m
[J)
The AMB represents a boundary between distinct Precambrian basement lithologic / structural terranes as indicated by contrasting aeromagnetic anomaly patterns, similar to terrane subdivisions mapped within exposed Grenville province rocks in Canada.
The boundary corresponds to shallow dipping reflectors indicative of lithologic layering or low-angle faulting based on interpretation of seismic reflection data in east-central Ohio 160 kilometers to the south.
Similar geophysical signatures along interpreted Precambrian terrane boundaries exposed in Canada, are characterized by broad ductile fault zones, such zones are characteristic of ductile deformation which occurred at substantial depths in the crust during the Grenville orogeny (lGa).
High-angle brittle
- faults, apparently responsible for recent seismicity in nortbeastern Ohio, are not of the same origin as the
(}
Precambrian structures causing the AMB.
The low-angle ductile Precambrian structures delineate a contrast in basement physical characteristics which likely controlled or focused subsequent brittle fault formation during periodic subsidence of the Appalachian basin in the Paleozoic.
The present northeast-southwest directed stress orientation is favorably aligned to permit strike-slip motion on high-angle faults trending north-northeast and northwest which apparently occur throughout the EMMB.
As the whole EMMB is apparently not equally active, localized factors such as brittle fault geometry, cross-cutting structures, and the changes in the trend of the AMB, and a positive circular gravity enomaly west of the 1986 epicenter. potentially interact to impede or lock the brittle faults resulting in localized increased stress build-up to failure.
Examination of various imagery data including satellite, high-altitude color-infrared, and low-altitude black and white, h) along portions of the AMB between Akron and Ashtabula, has revealed m
1993J
- 30
- Weston Geophysical
fg lineaments, a small portion of which are subparallel to the AMB.
U The majority of the broad-scale lineaments are correlated with sittficial features, including stream channels, beach strandlines, and glacial morain,es.
Smaller scale lineaments observed on the high and low altitude photographs are similar in scale and intensity to lineaments typically caused by jointing of the bedrock.
- However, field reconnaissance of available bedrock outcrops shows no correlation of the predominant observed structures (joints) with the AMB.
Evidence of northwest-trending brittle structures in Pennsylvania and eastern Ohio is apparent from aeromagnetic and gravity data, aerial imagery, structural and lithologic facies mapping of the Paleozoic section, and mapping of brittle structural fabrics.
Based on this evidence, northeastern Ohio is bracketed by the extension of two basement controlled northwest-trending lineaments; the Pittsburgh-Washington lineament which extends to cleveland coincident with the suffield-Highlandtown
- faults, and the Tyrone-Mount Union lineament intersecting the extreme northeast corner of Ohio.
Smaller northwest-trending features between these two include Wagner-Lytle lines extending from western Pennsylvania into northeastern Ohio, satellite imagery lineaments in northeastern
- Ohio, and northwest-trending discontinuities in the northeast trending AMB and Eastern Midcontinent Magnetic Belt.
These brittle features segment the transitional precambrian boundsry, (AMB) as well as the EMMB, thus distributing stress over a broad region.
1993J
- 31 +
Weston Geophysical
/G' 2.9 References NJ
- Aggarwal, Y.P.,
1987, Seismicity and tectonic structure in Northeastern Ohio:
Implications for earthquake hazard to the Perry Nuclear Power
- Plant, Report to Ohio Citizens for Responsible Energy, Inc., 28 pp.
Beardsley, R.W., and Cable M.S.,
1983, overview of the evolution of the Appalachian Basin, Northeastern Geology, vol. 5, p. 137-145.
- Briggs, R.P.,
and Kohl, W.R., 1976, Map showing major fold axes, satellite imagery lineaments, elongate aetoradioictivity anomalies, and lines of structural discontinuity, southwestern Pennsylvania and vicinity, USGS miscellaneous field studies map MF-815.
Cleveland Electric Illuminating Company, 1979, The Perry Nuclear
()
Power Plant Units I and II.
Final Safety Analysis Report, Cleveland, Ohio.
Coogan, A.
H.,
1987, Reservoir sandstone bodies in Lower Silurian Clinton sandstone interval, eastern Ohio, Am. Assoc. Petroleum Geologists Eastern Conference, October 1987. Columbus, Ohio.
- Davidson, A.,
1986 New interpretations in the southwestern Grenville Province, in The Grenville Province, eds. J.M. Moore, A.
Davidson, and A.J.
Baer, Geol. Assoc. Canada Special Paper 31, p. 61-74.
- Engelder, T.,
1985, Loading paths to joint propagation during a tectonic cycle:
an example from the Appalachian Plateau, U.S.A.,
Journal of Structural Geology, vol.
7.
nos. 3/4, p.
459-476.
O 1993J
- 32
- Weston Geophysical
Engelder.
T.,
1982 Is there a genetic relationship between selected
.OI V
regional joints and contemporary stress within the lithosphere of North America?, Tectonics, vol. 1, p. 161-177.
- Engelder, T.,
and Geiser, P.,
1980, on the use of regional joint sets as trajectories of paleostress fields during the development of the Appalachian Plateau, New York, Journal of Geophysical Research, vol. 85, no. Bil, p. 6319-6341.
Gonterman, J.R.,
1973, Petrographic study of the Precambrian basement rocks of Ohio, Unpublished, MS Thesis, The Ohio State University.
- Gray, J.D.,
1982, subsurface structure mapping of eastern Ohio, in an integrated study of the Devonian-age black shales in eastern Ohio, eds.
J.D. Gray, R.A.
- Struble, R.W. Carlton, D. A. Hodges, P.M. Honeycutt, R.H. Kingsbury, N.F. Knapp, P.L. Majchszak, and D.A.
Stith, draft report prepared for U.S.
DOE Morgantown Energy Technology
- Center, Morgantown, West
- Virginia, p.
3.1-3.13.
- Herrmann, R.B.,
1978 A seismological study of two Attica, New York Earthquakes:
Bulletin of the Seismological Society of America, vol. 68, no. 3, p. 641-651.
- Hodge, D.S.,
- Eckert, R.,
and Revetta, F., 1982, Geophysical l
signature of central and western Ohio, in New York State l
Geological Association field trips guidebook, eds. Edward J.
Buehler and Parker E. Calkin, p. 3-17.
Knight.
W.V.,
1969, Historical and economic geology of Lower Silurian Clinton sandstone of northeastern Ohio. Am. Assoc.
Petroleum Geologists Bull., v. 53, no. 7, p 1421-1452.
1993J
- 33
- Weston Geophysico:
(\\
- Lavin, P.,
- Chaffin, D.L.,
and Davis, W.F.,
1982, Major lineaments U
and the Lake Erie-Maryland crustal block, Tectonics, vol.
1.
no. 5, p. 431-440.
- Maki, M.U., 1986, Knox Unconformity in subsurface of northern Ohio, Unpublished,MS Thesis, Kent State University.
- McMullin, W.D.,
1976, subsurface geology of the Lower Silurian Grimsby
("Clinton")
sandstone of Ashtabula
ontario Geological Survey, 1985. Evaluation of the conventional and potential oil and gas reserves of the Devonian of Ontario (9 volumes), open file report 5555, 178 pp.46 figures.
- Pees, S.T.,
1986, Geometry and Petroleum geology of the Lower Silurian Whirlpool formation, portion of NW Pennsylvania and NE
()
Ohio Northeastern Geology, vol.8, no. 4, p. 171-200.
- Pomeroy, P.W., Nowak, T.A.,
Jr., and Pakundiny, R.H.,
1978.
Clarendon-Linden fault system of western New York; a vibroseis study, New York State Museum, Journal series no. 244.
Rodgers, M.R., and Anderson, T.H., 1984. Tyrone-Mount Union cross-strike lineament of Pennsylvania; a major Paleozoic basement fracture and uplift boundary, AAPG Bull., vol. 68, no. 1, p.92-105.
Root S., Angerman, M.,
- Harper, S.,
and MacWilliams, R.,
- 1986, Tectonics of the suffield-Highlandtown faults.
- Root, S.I.,
and Hoskins, D.M.,
1977. Lat. 40*H fault zone, Pennsylvania; A new interpretation, Geology, vol. 5, p. 719-723.
~~
\\_/
l 1993J
- 34
- Weston Geophysical
,~
- Root, S.I.,
1978. Possible recutrent basement faulting, Pennsylvania, open ' file report, Pennsylvania Geol. Survey, 4th ser.,
- Santini, R.J., 1983, The Silurian Newberg (Lockport) gas pools in Summit County. Ohio complex structural-stratigraphic petroleum accumulations, Northeastern Geology, V.5, no. 3/4, p. 181-191.
- Turek, A.,
and Robinson, R.N., 1982. Geology and age of the Precambrian basement in the Windsor, Chatham, and Sarnia area, southwestern
- Ontario, Can.,
Jour.
Earth Sci.,
vol.
19,
- p. 1627-1634.
Van Tyne, A.M.,
1975. Subsurface investigation of the Clarendon-Linden structure, Western New York, open file report, New York State Geological Survey, Albany, New York.
- Wagner, W.R.,
and Lytle, W.S.,
1976 Greater Pittsburg region revised surface structure and its relation to oil and gas fields. Pennsylvania Geol. Survey, 4the Ser. Inf. Cire. 80, 20 p.
Wynne-Edwards, H.R.,
1972, The Grenville Province, in Variations in Tectonic Styles in Canada, R.A. Price and R.
J. Reynolds eds.,
Special Paper No. II, Geol. Assoc. of Canada, p. 264-334.
i l
O 1993J
- 35
- Weston Geoohysical
.. - ~.. - - -
t 9
4 f
C i
l f
i f
f 7
I FICURES i
r a
?
i O i
l i
I 5
4 4
h I
i e '
g I
I i
7 i
l I
i i
1 I
i I
f
)
O i
l e
I i
Weston Geophysical l
i i
!~~.-w,
.,,c
- n.
d'
./
W d
\\
in' g'
.t
.4 a'
di CHURCHILL
\\
PROVINCE *'
h.
NAIN y
g r
PROVINCE f x*
.I (3
~~~- %. h.. e
' i U,%
+
'u/
- */
,,;,.~,.,
.f. c.
, k,W**z '*r'.,
O
,l
..m.
^ gy>
c.,,.<,. - i.
,s tons 8
SUPERIOR PROVINCE oi..a vi c q,f,, g/
,.. W
.pg
- te,,,
g
,s
\\
.~~, +s.
'h. s,. %
eg
/
SOUTHERN e
s46=<='
F
~..
,, s 'o*j '
ju, +
/m ghea PROVI CE
,p;g,;a #
".s <
ws; m.::
%.. 'oa',
j+
g,,
/
N
'b NTjf' p,,,' 8
'. e, a.
g,
s j
lA *
. CP'e t.a, Geg ell 9
/
b 8GWR*'
D gyg,g.e Tyey, f
tf s
l
- bV
.6>
\\. /. -o.c.
w M 0*'I "'
s 4
g Cal.4 2.*. '.
e4 peeage.
f I
LEGEND
,/V
'N 4 a,i r... u.og.,.. w-.~,.
6" !].....
j Ow., t g.. l.4@t p.thaC gA.. 4 5 L-t.in S wee, *=
0,. wies. inc.two.s.,..c 6 upe.cevuw ge e.a si.e, g.
t ent'
^
f.cs c
n.ed.
..on
.... - e
.,4.,,....,.,,,,.......
N^L t
~ ~ ~'--'#
---. o, i..
4...
4
- f Y
V ef T
Y Source: Wynne. Edwards,1972 l
FERRY HUCLEAR POWER PL ANT ONp THE CLEVELAND ELECTRIC lt f.,UMIN ATING COMP ANY t
i
[~'
Tcctonic Framework of the Grenville Province FIGURE 2.1 m
O Depth Oraphie
(
\\
(f t.)
Le,
(./
4086.0 -
CEI 193 CAtJ410 VEL.L. el PRECAMBRIAN CORE DESCRIPTION DEPTH 6065.3' - 6016.0*
6065.3' - 6061.1'
' Weathered green to purple fine grained chlorite schist with entrained pegnatite: irregular [not planar) stickensided surfaces with erratic orientation: mylonitic texture more intense near 6061.0': zone reduced to many small chips,
,e broken fragments, becoming more massive approaching sylonite p
+
- y +.
- zone.
6067.1'- 6068.1' Pegmatite, ductile mylonite shear zone: Pegmatite deformed af into small s-shaped fold in fine-grained chlorite schist
+
/
p.
matrix.
k 60Q8,0*
Tight irregular minor displacement fault (4
's use thick.
(dip 300) cuts mylonites fractures in core terminate
~
in rhyolite intrusive over next 6": contact relationship between rhyolite and schist not apparent, likely lost during coring and storage.
/a a
6068.4' - 6072.4' Metavolcanici reddish brown medium-grained rhyolite is sound 40f o.0 -
with finely disseminated quartz veinst massive core, no N
stickensides, a
s
$ /'
)
i e
s e
a b
t' U
4, ',-
/
e 6072.4' - 6074.1' Chlorite schist. shallow dipping foliation
[-
300):
multi-oriented slicked surfaces, scue opens no prcuinent through-going orientation) 450 to horizontal surfaces are irregular and discontinuous zone reduced to many small
-~. /
chips. broken f rapnents.
p.','
e#
1
/ vp 6014.1' -6415.5' Metavolcanic, black to reddish black meditn-grained 40f 8.0 -
[
metadiorite irregular small veins.
las thick, dolenite.
calcite mineralization oriented frm horizontal (irregular) to vertical (planar) cut the core.
h' a
e-PERRY HUCLE AR power PL ANT ANp THE CLEVELAND PLECTRIC ILLUMIN ATING COMPANY CALHIO Well #1 Precambrian Core Description FIGURE 2.2
1 I
i (7'.);
\\*,.
I m,...mo.q l
~
i!!
ll!"' "ijji' Ddli!' !!llil!!!L'il!l i!sii:li
- 111 l
i
=
g i
!g i 1
[)
I I
I I,I I
j m
I
}
l f
can oe e
W ew=
m
- s
{
sississieesas
(
pstem esseias essesttvasise C>
f 1
I i
TI APERTURE CARD F.: J.7,....
[,,[,'[,7,",,,
Also Available On Aperture Card l I i
ljill j
21 i
i
~~
jIz =2 }
J 11111 j
- JJ l
e 111 I
8
- lli I d
t l'
i 3
3
!. [.
]
I h
I<
I 3y
}
I l-
}
mf
=- h==-
j j
]
2
, ; l
,I{I 1 1 4
ij, l}
1 1 1 3
3 1
],
i, i
1 1
j
]
j 1
11 L
J i i.
_q c
-s
.'C**'
f
)
c===*=
e - - (U f
Cam =
w s.-**
.r.
u.
m:,.
)
j l
88071201,98-O!
A PERRY HUCLEAR POWER PL ANT (A N p THE CLEVELAND ELECTRIC ILLUMIN ATING CouPANY Generalized Stratigraphic Section for Ohio FIGURE 2.3 A
_M
l t
I')
Period Group Formatloc twerutss Rtaoets er
/
Cov(wANGO Sh. ss, cd 0 600' CONNtJuT CHAD AKOIN sh se 0*tod CW UN oin.'
- sh a se os PERRYsBURQ8 sh,ss 5A 5' UPPER
.f!!
west reus sr ss,sh
<is ow cas C
O SONTEJ Sh 45' 850' Gas
[
ctNtstt sg ss,sh ee ood Tuttv ts o -D '
Cm p
uOSCOw Sh Gas uaunrou g g gygs $
- N t
MIDDLE uaRCEllus Sh Ces ONON DAG A La 2523f' Gos, ou EPRihGvALL Ss 0- so' pgg7gg gggg oRisKANY k
0*?d Ces HtlCERSERG QNQ y
0 tt<
EEPHE A @ OH Ed O**Y CAMitLUs Sh, Cypsum UPPER seuNe svRacusc ow, ss san 4or 22,5 VERNoN sh be LoCKPORT Dd 165' 2M Cos U
ROCH(STER sh MIDDLE
's"$70*T E tri 45d
'*8 cuurou REYNatts Ls O
'@u"$?
M,ss 7FItr' LOWER umu4 G
cas wwintpoot se o ts' Gas outtustoN sh rey soiv o.s
',g UPPER
,3,ggo
,,,,73 LoaR AINt sa 54d-7a:t f
MIDDLE rg[fffyg, t Ng, -{
h, si oss
_U "LOWER ru< m rn.v Tmts witt u ed l5 UPPER e4 THER(sa Del & ss' 47s 868 Gas O
poisS4 use s o' M s' ca s me.m PRECAMBRIAN o~t=5 m.tt.ouaRmTr.=
,3 Source: Harth,1979 PERRY HUCLE AR POWER PL ANT ANpp' THE CLEVELAND ELECTRIC C
ILLUMINATlHG COMPANY Composite O
Paleozoic Stratigraphic Section for Western New York PIGURE 2.4
~-
gw.n i
\\g~
I
/
,.a
&//,)f'
/
p
'NN
%M r-Q O
,/./ /-
9,
W 'N j
i 7
g b~
I b,
e s
g.,
's ' ;
.>,s
. o's
.,',,N,
.NN s
,,,.. 't,,
..,. s.,N n
- o.
\\
..,. c, r
\\.\\
\\
e.
o N
h
.O
\\.
+,,,,,'#
\\
e 9.
s.
Nh Q.g "'
s N. C
,c, N
s
'b s'i, W.
/
,,,c yM.
s.
~.
A
%x
/%,' /
s i 4
u /
i i
/ NS l
=
L ','
s
~.., ' ~
i,l o
C
\\,
o N~~2-I a
. -(.
e
(_
d
.e_,-,,.
g.
g e
- 6 g - e
'g
/
.llr;l
.e f
c?,2 1 I I 7
...t.....
i,.;
i
,* h \\
~,...,
l
/y 'toenestet ten,s a stans 1
,=*e,une tae o I
em.
\\
\\'
Ns\\ s%
- i...
sg,'
1,,t.<-.
q
' \\s' S',6' 4 b" :=:t :.e--
,/
K se
- =.';;'.....
" = ".".,;"'
,/',/.e
...a............
e,
\\ Q' / [,,,','df<
ti.
wei... em im
/'
.=. em i.es.sie,
,r a
7 Tl l
\\
l,,,<
1Y
/
,,,e' N\\\\,,,-
T f
- N es Ns
//
, g'f A1.o Avanable Ou N
s j % f',,
\\p N Aperture Card
/,/ N'
%g')N,///,/ /.%
N
#og I f / y',k,/ ',',/ / l G
y w
v aw-
,* 7
,,/
o so nao mi
/
! ~/.f s.
/
- rQ i
/
/
l'/
/
N g g o 712 0 l'8 8 - D'A.,
v,,,,, Of o
Q PERRY NUCLEAR POWER PL ANT fpNpp THE CLEYELAND ELECTRIC ILLUMIN ATING COMPANY e
g 4
0 Regional Tectonic Elements FIGURE 2.5 e
~
I o
~/.
eme s5o.
t,
)
l Mf at A.ta PNPP
.g
,..,4 '. j i
'<g
- ' /,.':
- +
- ....... j
...g.., *., *.
C
.i
..Y
(~-
g g
m,
~4tM Y
7 I!
- w f
N,
.u..
I i
+
+
t e.
+
T1
- APERTORb, CAllD e
Al.o Anilable on A1>crture Card 8807120196-03 3
Q, PERRY HUCLE AR POWER PL ANT THE CLEVELAND ELECTRIC e
ILLUMIN ATING Coup ANY w
. e 4
i 4
Well Locations FIGURE 2.6
m#
81.25 81.0 i
l o
%'~/
J
-: w'"" Y '
/kV
}- m y
e
~~'
X
./~
/
e-- s-q~:~ _.23
~.
r, f 2600 )
m
"' /
,j
/ /
./ /
~ -.
/
,- n.,..
n w
==.s
N 80.75 05 d'
TI
/,p@
APERTURE CARD p-
,/,
Albo Aggi]ab]e 99
+
/ /
+
A erture Carel P
~
o S MILES
,%D 5 KM contour intervat 20 feet
/
/ / /
88071201696-O b
/
/
y /
ILLUMINATING COMPANY
'+
e
+ - - ~
- Queenston Structure Contour Map FIGURE 2.7
\\
C e
we F
(
h.,
A f
Wst Geauta Canty l Agge g I
44-I I
l 1256
.eys.
979 339
.sae.
1 378 4m.
p I
r i-I.
t
_/
-~-
p v
A
.)
)
(..
-=-
INDEX MAP
/.
L AKE ER)E
/
l LAKE c- -
M ASMTABUL A
[_Tx; / !
i
^
l
- CUYAHQGA I
L,
.. _. _. J'.
r.
T Rta/Sgtt
.b.
.j t' SV/MT i L.-.._.I.
PORTAGE I
I I
l e-.,
e c
n e
l-A-
mai Sist
)
t I.
3413
)
3See f
32to L
(
f(N (g
(
c L
og y
e
[/
j.
V
]--
)
/
~~-
/-
s p/s f
~~
N
..asco
% N
,y[
S EES d
ixu APERTURE
~
CARD Aho Available On Aperture Card 88071201296-06 PERRY HUCLE AR POWER PLANT N
THE CLEVELAND ELECTRIC ILLUMIN ATING COMPANY Cross-Section A-A' Parallel to Strike FIGURE 2.8
81 25 81.0
/,g a 5f,/, c s.
i f
h?"
- a. 5
+
p--
" ^ '
80.75 60.5
~7 i
/
\\
KM contour inte vat: 20 feet l
APERTURE CARD
/
Also Available On Aperture Card 88071201i98 04
/
Delaware Structure Contour Map I
FIGURE 2,9
~
./*
/
y' 0
/
^
/
/D
- e
/
l l
d p
./ /
.2ga0 2160 -
~
2180
/-
~
i
- P200 I b) oo C
s 2220 /
- \\
2240-h, 2260 %
w.
(3
'2280 THOMPSON
.2300 ELEVATION CONTOURS, TOP OF PACKER CONTOUR INTERVAL: 20 FEET PERRY HUCLE AR POWER PL ANT (ANp '
THE CLEVELAND ELECTRIC ILLUMIN ATIN^. COMP ANY 0
1 2 miles Packer Shell Structure
{
Contour Map Id Detailed Area 0
1 2
3 kilometers l
FIGURE 2.10
'/*
.s*
/,/
.se r ~..
L)
PNPP /
go
/
j
/
p& ~
8 5 e
- c. O
/
.660
/
i
.6*
/
xJ i
700
/3 C/
{
l t
N
-.720 1
60 y-(.
/ -)
g 160 0
/
h
~
HOMPSON j
.s '
o
/
g*
/
)
ELEVATION CONTOURS, TOP OF DELAWARE CONTOUR INTERVAL: 20 FEET PERRY HUCLE AR POWER PLANT THE CLEVELAND ELECTRIC ILLUdlN ATING COW ANY Delaware Structure O
1 2 miles Contour Map l
,I I
Detailed Area 0
1 2
3 kilometers FIGURE 2.11
f
/.
O
/
/..
/
/O y
. /./
e
> =
g 8
.' e s
C.
( %. N fx. )
\\
s./ w.
N.
)
8
~~
/
5 THOMPSON a
i uJ l
'A PERRY HUCLE AR POWER PL ANT THE CLEVELAND ELECTRIC ILLU'JIN ATING CO=.P ANY 0
1 2 miles l
Well 1,ocations I
i i
i O
1 2
3 kilometers j
Detailed Area FIGURE 2.12
b
\\
\\
j
,, \\
\\
j i
Nf"
- %m
.A 3,
iN
!!S k'
(59
- ggy.
ggC
.4.p.
[/
'\\
f N' {
@I [
(-
L._'s,
gs 84
~~
~
~~
"p
/
s f
NN v~#lN s1 j
g N
)
g l
g g
k MENTOR so l~_-__
,2)
I b
\\
p e
N N-I LAKE ERIE
\\
Si
.ggCg j-
\\
k
_ i N
k i
\\
d EAST CLEVELAND
\\
EUCLIQ/
I
\\
N
<f
~..
l k
S.
_.L.-.
1pggMg -
e I
Ti I
APERTURE CARD l
'Also Available On I
Aperture Card g
(eg EXPLANATION
~
^
LINEAMENT TRAVERSE L._ _
l Gb I
l
[
k N
Q 1r D 1 ~ / j \\ I I4 ~ . ED l 43 l 0 5 MILES o 6 S KM 14 \\ l A 4 i 8807120198-07 t d 'g PERRY NUCLE AR POWER PLANT THE CLEVELAND ELECTRIC i l Ig~p ILLUMIN ATING COMP ANY w w 3 Interpreted Lineaments and ^ Field Reconnaissance Traverses 3 Along AMll l l jr ( ' / \\ l s nouxu 2.0 T l
q 3.0 gg0 PHYSICS C 3.1 Jntroduction Although the origin of midcontinent earthquakes is poorly understood, it is generally agreed that earthquakes of magnitude 5 and greater are related to reactivation of pre-existing upper crustal structures appropriately oriented with respect to the ambient prevailing stress field. These stresses likely originate by ridge push forces associated with oceanic construction at the Mid-Atlantic Ridge. Where the local deviatoric stress field exceeds the brittle fracture
- limit, an earthquake will occur.
This situation develops where the rocks are locally weak, the stresses are amplified or both occur. Unfortunately, the upper crustal crystalline rocks where the vast majority of the earthquakes occur in the midcontinent is poorly known because of the cover of cratonic sedimentary rocks that provide few clues to the underlying basement { rocks and the limited and poor distribution of outcrops and basement drill holes. Therefore, geophysical data which remotely sense changes in the physical properties of the crystalline rocks are used to investigate intrabasement structure and lithotype variations. Gravity and magnetic (geopotential) methods, which respectively map rock density and magnetic polarization contrasts. have been l extensively used in this regard because of their ability to map the crystalline crust and the availability of these data on a regional scale. However, the geological interpretation of these data is not unique and thus interpretaticns are constrained by combined analysis of these data and extrapolation from poorly distributed seismic reflection profiling and direct information from basement outcrops and drill holes. Accordingly, a comprehensive geophysical program has been conducted to investigate the structural, and lithologic character of the earth's crust in northeast Ohio in the vicinity cf the 1986 1.er uy earthquake and to ascertain the extent and nature of the Akron 1993J
- 36 e Weston Geophysical
Magnetic Boundary, a relatively sharp change in the characteristics of the magnetic anomalies derived from the upper crustal rocks, and its related basement geologic provinces. The geophysical element of this program is based primarily on the compilation, processing and analysis of regional magnetic and gravity anomaly data from the U.S. and Canadian data repositories and detailed data acquired by CEI in the vicinity of the Leroy earthquake. The importance of regional data and analysis is~ emphasized because of the need to place the crystalline crust into a regional geological context. The interpretation of these data is complimented by available crustal seismic reflection data, basement drill hole information and geologic mapping in the Grenville outcrop area in Canada along the regional strike of the geopotential anomalies. The geophysical program consists of several fundamental steps. Kirst. regional magnetic and gravity anomaly digital data have been t: %911ed for an extensive region around northeastern Ohio from 44 latitude and 78.5 -84.8 W approximately 39.4 longitude. These data have been composited, gridded, and registered on a 2 km square grid. Second, a variety of secondary anomaly maps have been derived from the original anomaly grids by wavenumber domain processing to enhance particular attributes of the anomaly field in both contour and colored map form (see Appendix). These include wavelength filtering, strike-sensitive filtering, derivative, continuation, reduction to pole, and correlation of gravity and magnetic anomaly maps. The original and derived maps provide the basis for visual inspection, correlation and interpretation leading to the development of conceptual geologic models. The regional extent of these maps is particularly important in relating the geopotential anomalies to the geologic nature and seismicity of the mapped Grenvillian rocks in the Canadian Shield. Third, the geopotential anomaly maps and related profiles are used to identify the distribution and continuity of the geologic trends slong and adjacent to the Akron Magnetic Boundary. Fourth, the
- O 1993J e 37
- Weston Geophysico!
4 9 accumulated data and conceptual geologic models developed from these .(A) U data are used aA a foundation for gravity and magnetic enomaly modeling on which to baso geologic interpretation. 3.2 Jnterpretation 3.2.1 Regional Basement Framewog Grenville age rocks crop out in eastern Canada in the Precambrian Shield, to the south in the Adirondack Mountains and as far south as the southern Appalachian Mountains. However, the sparse and widely distributed nature of the outcrops and supplementary basement drill hole samples of Grenvillian rocks in the eastern U.S. and the adjacent midcontinent has inhibited definition of the western limit of the Grenville orogen, the so called Grenville Front, and identification of structural / lithologic terranes within the subsurface extension of the Grenville Province (Lidiak and Hinze. O 1988). Even where the basement drill holes are relatively numerous b as in Ohio near the crest of the Cincinnati Arch, the samples which are largely cuttings and penetrate only a few meters into the basement crystalline rocks provide essentially no evidence regarding structure, and the lithologies are difficult to interpret in terms of terranes which have been identified in the outcrop regions ot the Canadian Shield. This problem is exacerbated by the intensity of chemical alteration of the surficial rind of the subcropping crystalline rocks (Ceci. 1985). As a result, the mapping of Grenville Province in the U.S. has been primarily by indirect geophysical methods built upon benchmarks provided by the lithologies and isotopic ages of basement drill holes. j Regional geologic investigations of the Grenville Province in the Canadian Shield have led to identification of several major subdivisions or terranes (e.g.. Wynne-Edwards, 1972
- Davidson, f
1985). Recently more detailed investigations supported by peophysical studies have defined these terranes more precisely and l 1993J
- 38 +
Weston Geophysical
g suggested additional subdivisions or subterranes (e.g., Moore et V al., 1986; Forsyth et al., 1968). Mapping of these units in the buried basement of the eastern midcontinent has been difficult and slow for several reasons.
- First, the identified terranes and subterranes of the Canadian Shield are not necessarily characterized by diagnostic lithotypes.
Thus observations at a few, widely distributed points where drill hole samples are available do not provide critical information for mapping purposes. Second, the boundaries of the zones are often gradational, measured in kilometers or even a few tens of kilometers and with few exceptions the boundaries are not marked by characteristic geophysical anomalies which are continuous along their length (Forsyth et al.. 1988). Third, the extension of the Grenvillian rocks south of the outcrop limit of the Canadian Shield in Canada has been investigated to only a limited degree. As a result there is a gap between the southern outcrop limit and the U.S. border. Fourth, there is increasing evidence that many of the surface Grenvillian rocks are allochthonous having been tectonically transported for tens or b perhaps hundreds of kilometers (e.g.. Beardsley and Cable, 1983: Davidson, 1985). As a result, geophysical signatures are a mixture of both shallow tllochthonous rocks as well as deeper autochthonous or parautochthonous
- rocks, complicating the identification of terrane and subterrane units.
Fifth, there is no evidence that the subdivisions of the Grenville Province as mapped in Canada are continuous into the U.S., Mapping in Canada suggests a complexity in the subprovinces that limits their strike length. l The western margin of the Grenville Province, the Grenville Front. in Canada is mapped as a structural and/or metamorphic boundary between the high grade metamorphic rocks originating in the 1100 Ma Grenville orogeny and the granite /greenstone rocks of the older Superior Province to the west. Profound geopotential ancvnalies and changes in their pattern at the Grenville Front together with limited basement drill samples h."e been used to extrapolate the province boundary southerly across Lake Huron into the Southern 1993J
- 39
- Weston Geophysical
i Peninsula of Michigan and'into western Ohio (O'Hara and *,iinze, 1980; Lidiak and Hinze, 1988). The Grenville Front extends southerly from the Michigan-Ohio border at approximately 83 30'W where the Grenville Province is juxtaposed with the 1.5 na old Central Province felsic anorogenic rocks. The Grenville Front in Ohio (Lucius and vonFrese. 1988) ir marked by a change in both the magnetic'(e.g.. Figures 3.1 and 3.2) and gravity (e.g.. Figures 3.5 and 3.6) anomaly patterns, amplitudes, and gradients._ Recent seismic reflection profiling in Lake Huron (Green et al., 1988) and in Ohio by COCORP across the Grenville Front show that it is characterized by a eastward dipping ductile shear zone (Grenville Front Tectonic Zone) which at least locally cuts through the entire crystalline crust. The high-grade metamorphic rocks of the Grenville Province have been thrust westerly and upward along this shear zone over the Central Province or older rocks to the west. The crust is thickened by a few to several kilometers in the Grenville Province along the Front. The broad Central Gneiss Belt g I crops out east of the Grenville Front Tectonic Zone. however, this terrane appears to pinch out in northern Ohio (Lidiak and Hinze, 1988). The Central Metasedimentary Belt which occurs immediately i east of the Central Gneiss Belt in Canada occurs adjacent to the l Front zone in Ohio. The COCORP seismic reflection profile wt.lch images the entire crust and transects west to east across Ohio at roughly 40 15'N has not been fully processed. However, visual inspection of the unmigrated data indicates that the Central Metasedimentary Belt east of the Grenville Front Tectonic Zone is structurally complex with considerable faulting and probably tight folding and intrusias. A series of shallow west dipping reflectors extend from the upper crust through the entire crust in eastern Ohio at roughly 82 W to the West Virginia border. These reflectors flatten out updip and appear to overturn to an east arly dip in the upper crust. These westerly-dipping reflectors may represent a set of ductile shears Os l-1993J
- 40
- We9on Geophy9 Col
_., _ _ _ _, - _,_...____ m _ _ _ _,.. _... _ _ _, _ _. _, _ _ _
similar to the Grenville Front shear zone which originated at the ) time of the continental collision and associated compressional event v causing the thrusting at the Grenville Front. The western-most of these deeply penetrating reflectors suberops at the basement surface at the approximate positions of the AMB. Beardsley and Cable (1983) have shown that shallow dipping reflectors are prominent in the upper Precambrian basement of central and eastern Ohio and the area adjacent to the east. The reflectors characteristically dip east or southeast, but other prominent dips are present. The source of these reflectors remain equivocal, they can be related to thrusting, doming, or lithologic layering within the Precambrian Grenville rocks (Lidiak and Hinze, 1988). In summary, basement drill hole samples and extrapolation of outcropping crystalline geology in the Canadian precambrian Shield using geopotential data provide evidence that central and eastern O' Ohio is underlain by a basement which was involved in the Grenville orogeny 1100 Ma ago. East of the Grenville Front which extends north-south across western Ohio, the basement is composed of an apparent extension of the Canadian Central Metasedimentary Belt. This terrane was complex 1y deformed duririg the Grenvillian compressional event which thrust the deformed high-grade metamorphic rocks upward along the Front and possibly along a related set of shears dipping to the west in eastern Ohio. However, the overlying Phanerozoic sedimentary rocks are undeformed where the COCORP seismic reflection profile crosses the westerly-dipping deeply extending reflectors, indicating that the tectonic mechanism responsible for this deformation was terminated prior to Phanerozoic sedimentation 600 Ma ago. j O 1993J
- 41
- Weston Geophyucal
3.2.2 Eastern Mideontinent Magnetic Belt The Grenville province basement rocks of Ohio are considered to be largely made up of the subsurface extension of the Central Metasedimentary Belt of the Canadian Shield. This belt which contains the main outcrops of the Grenville Supergroup is characterized by an abundance of supractustal rocks which include marbles. calesilicates, quartzites. paragneisses, amphibolites, and metavolcanic rocks that apparently overlie older gneiss. These rocks were deposited from 1280 to 1100 Ma ago and were intruded by widespread felsic to mafic plutons during roughly the same time span. They have been highly deformed and metamorphosed to the amphibolite or granulite facies. The boundaries of the Belt and its subterranes are tectonic in origin and are commonly identified by zones of highly strained gneissic tectonites. The subterranes are recognized by diagnostic lithologic assemblages, structures, and metamorphic grades which lead to characteristic geopotential signatures which can be used to extrapolate them from the outcrop to O the subsurface in the U.S. 1 Lidiak and Hinze (1988) have recognized a subterrane of the Central Metasedimentary Belt based largely on geopotential anomalies which does not outcrop in the Canadian precambrian Shield, but makes up a major segment of the basement of Ohio. This unit. the so-called Eastern Midcontinent Magnetic Belt (EMMB). is recognized by a broad zone of consistent geopotential anomaly attributes, the most prominent of these are relatively intense curvilinear magnetic anomalies that extend from immediately north of western Lake Ontario southwesterly across Lake Erie and southwestern Ontario into northern Ohio where it turns south and continues southward to at least central Tennessee. It is identifiable on essentially all the magnetic anomaly maps. but is particularly prominent on Figures 3.1. 3.2. 3.3. and 3.4. It is clearly evident on the upward continued magnetic anomaly maps and their derived maps (Figures 3.7. 3.8. and 3.9). testifying to the depth extent of the unit well into the upper 1993J
- 42
- We9on Geodhyscal
crust. Positive gravity anomalies generally correlate with the magnetic maxima in the EMMB over a dominant wavelength range of 30 to 40 km (Figures 3.6 and 3.10). The positive correlation between the magnetic and gravity anomalies is evident on the maps which correlate the anomalies (Figure 3.11). The short wavelength gravity anomalies appear to originate from lithologic variations in the upper crust and are superimposed on broad positive and negative gravity anomalies whose sources are likely to be in mid to deep crustal level ranges. Geophysical anomalies and basement drill hole data suggest that the EMMB in northern Ohio is dominated by granite
- gneiss, syenite gneiss, granodiorite gneiss, mafic schists and gabbros. Minor metasedimentary rocks are anticipated.
The northwestern boundary of this subterrane in Ontario and northwestern Ohio juxtaposes with the Central Gneiss Belt. Parther south the limit of the unit is the Grenville Front and the eastern boundary of the intense magnetic linears and correlative gravity anomalies is the Akron Magnetic Boundary. It separates regions of high amplitude anomalies on the west from low amplitude, broader magnetic anomalies in easternmost Ohio and adjacent regions to the east. The EPMB has been subdivided into six separate segments free Ontario to Tennessee by Lidiak and Hinze (1988) on the basis of cross-strike discontinuities and minor variances in geophysical signature believed to be related to different 11thotype assemblages. The cross-strike discontinuities extend from the western margin of the EMMB in a generally east-southeasterly direction across the Belt and perhaps into the adjacen*: Grenville subterrane. Although uidiak and Hinze (1988) draw these discontinuities as individual lines. it is apparent that the boundaries between the segments of the EMMB are zones rather than lines. The units and discontinuities are particularly evident on the magnetic anomaly maps. The discontinuities as mentioned by Lidiak and Hinze (1988) are of ten coincident or closely associated with lineamento previously observed 1993J e 43
- Weston Geophy9 col i
in geophysical anomalies and bedrock geologic features. Three '_) identified segments of the EMMB occur in the study area - the Lake Erie
- segment, the Northern Ohio
- segment, and the Central Ohio-Northern Kentucky segment.
3.2.3 bkron Magnetic Boundary The Akron Magnetic Boundary (AMB) which forms the eastern margin of the EMMB is one of the more obvious features visible in both the regional and northeast Ohio magnetic anomaly maps. It is a trend which separates regions of intense anomalies on the west from low amplitude, broader anomalies on the east and thus forms the curvilinear eastern boundary of the EMMB. The AMB is not evident on the Bouguer gravity anomaly map except where wavelengths of 20 to 40 km are passed (Figures 3.6 and 3.12). The trend of this feature is essentially north-south in central Ohio, it turns to the northeast at roughly 41 N and continues across Lake Erie to
- 19 30'W.
r3 42 30'N where it turns abruptly to the north-northeast. continuing U across the eastern end of Lake Ontario. By extrapolation and correlation with the magnetic anomalies in Canada, this trend marks the western limit of the E12evir terrane of the Central Metasedimentary Belt although the anomalies are not continuous throughout its length. The AMB is mapped on the basic of an abrupt change in the overall magnetic polarization of the basement rocks on either side of the trend which reflect their lithologic composition. The limited wavelength of the magnetic anomaly pattern east of the AMB and the generally correlative magnetic and gravity anomalies indicate alternating sequences of curvilinear trending gneisses and schists of varying mafic composition. The positive anomalies in ooth the magnetic and gravity anomalies will correlate with the more mafic composition. The exact nature of the boundary between the EMMB and the Elzevir terrane, the AMB. is unclear. The seismic reflection data and the long-wave-length gravity anomalies do not support an U,o 1993J
- 44
- Wesen Geconysico!
interpretation of a profound vertical discontinuity or fault. By extrapolation into the canadian Shield, the boundary is likely to consist of highly strained. ductily deformed layered rocks. The consistent trend and cont ra.Jting amplitudes and wavelengths on either side of the AMB suggest the possibility that the rocks of the EMMB may continue to the east beneath the relatively non-magnetic. lower metamorphic grade rocks of the E12evir terrane. Acccrding to this hypothesis the magnetic anomalies east of the MB are broadened and attenuated in contrast to those of the EMMB by an increased depth from the surface. To test it. four west-east magnetic anomaly profiles were constructed across the MB. The profiles west of the AMB were upward continued to 2.0 and 5.0 km. The character of the profiles east and west of the AMB are quite similar when the data west of the AMB were upward continued to these elevations. The conclusion is that the anomalies east of the AMB are caused by anomaly sourcer, similar to the EMMB. but which are at a depth of several kilometers greater than to the west of the AMB. This visual comparison was verified by comparing the amplitude spectra from d east of the AMB to the 2.0 and 5.0 km upward continued spectra of the profile west of the AMB. The results are quite similar. This interpretation is consistent with the seismic reflection data and would suggest that the AMB is not a profound vertical fault margin, but represents the subcrop of a boundary of a more magnetic zone to the wast overlaid by a less magnetic unit to the east. This layering could either be structural by virtue of westerly thrusting of a less magnetic unit over a more magnetic zone or it could be stratigraphic and caused by dcaing or relative uplif t in the regior of the EMMB. The AMB. the contact between the two crystalline rock l units. is tenatively interpreted as a low-angle thrust fault which steepens near the subcrop at the AMB. Gravity and magnetic modeling along two profiles perpendicular to the AMB produce results which are generally consister.t with similar modeling of the Ohio crust by Lucius and vonFrese (1988). The modeling shows that the magnetic and correlative gravity anomalies O 1993J
- 45
- We9on Geophy9 col
i rw kilometers of the can be satisfied by sources in the upper e basement crystalline rocks. The anomalies are best satisfied by sources with steeply dipping boundaries. These boundaries are too steep to be mapped in the seismic reflection profiling and 91ve support to the vertical boundaries along and parallel to the AMB which extend for-several kilometets into the crust. They are associated with lithologic contacts that are caused by steep folds of varying lithologic units, faulting or locally by intrusivos, f It is significant to note that there are several geopotential lineaments within the EMMB which parallel the AMB or branch off from f it. These are particularly evident on a series of profiles of west-east gravity and magnetic anomalies and their horizontal gradients. Geopotential lineaments based on similar anomaly features can be traced from profile to profile across the area. The mapped position of these lineaments are shown on Figures 3.13, 3.14. and 3.15. The point is that the AMB is simply the eastern limit of G the intense anomalies of the EMMB and several other geopotential O lineaments occur within the Belt. In a regional context the AMB is smoothly curving, but in detail it is complex. This complexity is due to along strike lithologic variations and cross faults. There are two classes of cross faults. Primary cross faults which appear to transect the entire EMMB - several of these are noted along its strike length and divide it into discrete segments - and much more numerous secondary cross faults which do not transect the entire l Belt. The boundary undergoes two major changes in strike, one in northern Ohio (approximately 81 45'W. 41 N) from approximately N20 E in the south to N45 E and another less well defined one in eastern Lake Erie at approximately ~19 30'W. 42 30'N, from N45 E to N20 E in the north. f The AMa is not continuous along its entire interpreted length. Notably at the common intersection of Ohio. Pennsylvania and the Lake Erie shoreline an extensive area of higher amplitude, sharper magnetic anomalies occurs east of the AMB which is roughly 1993J
- 46
- l Weston Geophyscol
correlative with a gravity minimum. A similar magnetic zone occurs O east of the AMB in easternmost Lake Erie. These zones do not appear to be truncated abruptly as might be expected by steep faulting. These zones and their relationship to surrounding anomalies are consistent with the rocks of the EMMB occurring beneath the Elzevir terrane rocks and exposed occasionally in "windows" where the l-E12evir rocks are thin or even absent east of the AMB. l l l l 1 O l l l l O 1993J e 41
- Weston Geophyvcol
3.3 References %_/ Beardsley, R.W., and Cable. M.s. 1983. Overview of the evolution of the Appalachian basin: Northeastern Geology. v. 5. p. 137-145. Ceci. V.M., 1985. Petrology and geochemistry of Precambrian rocks from the basement of Ohio (M.S. Thesis): Pittsburgh, Pennsylvania, University of Pittsburgh. 298 p. Davidson. A., 1985. Tectonic framework of the Grenv1.le Province in Ontario and western Quebec, Canada, in Tobi. A.C., and Touret. J.L.R. eds.. The deep Proterozoic crust in the North Atlantic Provinces: Dordrecht. D. Reidel Publishing Company. NATO Advanced Science Institute Series. ser.C. v. 158, p. 115-215 Forsyth. D.A.. Thomas. M.D.. Real. D. Abinett. D., Broome. J., and Halpenny. J., 1988. Geophysicel investigations of the central metasediaentary belt. Grenville Province: Quebec to northern New \\ York Utate: submitted to Proceedings of the 7th international Basement Tectonics Meeting. 30 p. Green. A.G., Milkereit. B., Davidson. A., Spencer. C.. Hutchinson. D.R.. Cannon. W.S. Lee, M.W. Agena. W.F., Behrendt. J.C., and Hinze. W.J., 1988. Crustal structure of the Grenville Front and adjacent terranes. Geology. in press. Hildenbrand. T.G.. 1981. Filtered magnetic anomaly maps of Ohio. U.S. Geological Surv: Map GP-967 scale 1:1.000.000. Hildenbrand. T.G.. and Kucks. R.P. 1984. Residual total intensity magnetic map of Ohio: U.S. Geological Sury. Map GP-961 scale 1:1.000.000. Hildenbrand. T.G., and Kucks. R.P., 1984. Complete Bouguer gravity nomaly map of Ohio, U.S. Geological Surv. Map GP-962, scale 1:1.000.000. 1993J
- 48
- Weston Geophypcci
F i ( Lidiak. E.G.. and Hinze. W.J., 1988. Proterzoic rocks east and southeast of the Grenville Front (Subsurface Grenville-Age rocks between the Adirondace Massif and the Black Warrior Basin) in DNAG Precantbrian Volume. Geol. Soc. of America, submitted.
- Lucius, J.E., and vonFrese. R.R.B.. 1988. Aeromagnetic and gravity anomaly constraints on the crustal geology of Ohio: Geological Society of America Bulletin, v. 100, p. 104-116.
Moore J.M. 1986. Introduction "the Grenville problem" then and now, in Moore. J.M., Davidson. A.. and Baer. A.J., eds.. The Grenville Province: Geological Association of Canada Special Paper 31,
- p. 1-11.
I 0'Hara. N.W., and Hinze, W.J. 1980. Regional basement geology of Lake Huron: Geological Society of America Bulletin, v. 91, p. 348-358. Wynne-Edwards. H.R., 1972. The Grenville Province, in Price. R.A. and O Douglas. R.J.W., eds.. Variations in tectonic styles in Canada: Geo. Assoc. of Canada Spec. Paper 11. p. 263-334. 1 i l O 1993J
- 49
- Weston Geophysical
in l l@ FIGURES O O Weston Geophyscot
'O w/ C L,. e1 x. c,fo 4~ > \\ s o m,. 'f Q N
- E a
,/ (v f 43 N 1 xt ~ umafmp, ? % gk g p2 e bW M[ 's ',nig j /cag? 4 N<te 3 1 , m#, y, ye 3'p %? e7 .aA Ad
- [ftpy $
jj.. V og u s% %g$d w A%V(h r if gm tw ,,.~ - r Eti.[ M j f] 39 N 85 w 84 w 83 w 82 w si w so-(
e 11 0 4 OB ,mm 'e, a x p 0 { o'iF F/'f Contour intervat 100 ni G / { 0 40 80 120 160 KM r{'{ A P F.R T W F. / y CARD dieo dVallable Oft Aperture Carti ()c) ) ~ b 8 8 0 712 01,9 e - O S [ b, a " = f m ^. =,: st " ' ILLUulNATING COMPANY 79'W 78'W Cornposite Total Intensity Magnetic Anomaly Map FIGURE 3.1 (
Ys R Y se, ( i 3 7 ~W q{ 9 d 4!f14 S 16SW mrb8[3 ?h m \\g( u e \\ M n G
- 3. ~
y 'o ugfr x y o o D )0: 00, 9 9e C d-d f7 3 c> 0 m 9 c \\ (!$3(d#a ' f o .2.~ L=M,W i 09 2h3f8 f $l c? a ? c h,'p $;3 f$I I g a '. (,g ( t u Yh~ f l o ~ b ?$$$$$N "Y5l O W 39 N ^ es w 84 w e3 w 82 w si w eo v ~ ~ ' '
'a .5 $w ab s o Fo es s oh ? f Contour intervat 50 ni 'O ',e gpg fa. 0 40 80 120 160 KM V f,/ ~ // b APEll'I'URE CARD 9 0 Aho Avausble On y Aperture Card O / r' 8807.120196 -()O gq PERRY NUCLE AR POWER PL ANT LLuvsftwecoupawy Bandpass Piltered (20 - 40 km) 73,w Total Intensity Magnetic Anomaly Map PIGURE 3.2
t / /* } J fJ n 1 -... h u aEs3HB2FS ~ ? %,EEUR$ ~ w angenOy h1?$ N8h9rdN b c~ / f } g kf 7 c / m .,.s $iNL%@h d@ l sen mow # 2-40'30'N i J% Q & f~f (f) e-O /T o A/ n / s 82'W 81 %
() 7T O& Q> - i U tW f1 ?V k BEh L e T/ J ] contour intervat 100 ni g %.A// lh / / 0 20 40 60 80 KM }) [lV s / APEll UnE
- j
/ / CARD // / ( 'f g/ Also Avellable On h q Aperture Card N p#/ L. 8 8 0 712 01'9 fl - I O O----- N N-PERRY NUCLE AR POWER PL ANT g T H e c 'e v 5 ',^",o 5 ',5 c 7 aic 80 w 79 30w ,y composite Total Intensity Magnetic Anomaly Map FIGURE 'J.3 o
i,- JMEBRemn ETEMBEF i ~ yu,a g gu s sn m N t A. rc W)g & nun ,cc @b 1 IN Dbkw"dGlwn a w N3,bd 1 h ubbYkh?$hhb . ~.19pkW MEP3 82'W 81"W ~
fTh ? ( O 4 \\ 0 l/ q f ' / /) $)h} %( Go' )D hdb b'f C $ l// Contour intervat 50 nT kf/b / W sE ~i el /]n ,tA 0 20 40 60 80 AM &lff O snNeva CARD p Also Available 00 Aperture Crd [; / 3 k%l ,e, R M 3 8 0 712 01,9 e - l ( [iEEQ N\\ \\ x (j mE CL L^" 80* V 79'30 W t(UM N ATlNG COMPANY Reduced to Pole Total Intensity Magnetic Anomaly Map FIGURE 3.4 r*
-~# 4 4* N Q} C/ QW:== y ) ~ f)G M{fy e?? s 43'N v w/" 88 qdJ r f A e-a s, ,,.N . sv s,., ,a,; .m e
- h
) o 41'N m ay, a U ,l LVUfidd ~ ;(; ynsps 39'N 85'W 84'W 83'W 82'W 81'W 80'V. I i ev e, l
+ J h 2 4 to MC d tc hw /h 5 h n?) wuwe d m j Oj, !'"[s / Contour interval: 2 mGal .b e N 0 40 80 120 160 KM 3 N s 1 I i 1 I Q,V L rn P[ TI APERTURE CARD f p_/ Also Available On dt Aperture Card s yg/[V s 8 o n a o ve s - i 9- ,N ^ e umw 79'W 8'W Bouguer Gravity Anomaly Map 1 FIGURE 3.5
--w-- .--.m-n- f! / i
- 8. ~
RfE3Ei"4! 1 Ril3 BE.E.isa o aam ~ 85'W 84'W 83'W 82'W 81*W 80*V
(6 d adV E s c s n %g /( ) '* d R % 2 ' k 1 l F ?Q e y i, 'f 's s 1 ( SLb Contour intervat 1 mGal Y Y } Ui T TI s )g {} APERTURE i CANO tJ 1 IJ o ' Also Available On nO . Aperture Card ) ( 8 8 0 7 ] i'. O l' 9 6 - l 3 PERRY NUCLEAR POWER PL ANT LLUM N ATINO COMPANY 79'W 78'W Bandpass Filtered (20 - 40 km) Bouguer Gravity Map FIGURE 3.6 e'
NS3hi/Ma[*)fNt ..~ kb$ YYbl - -n.,,, @p rh,% C3 V ,) \\pqp,3 / m (' h . rsm kA h 4) T m E , ]_ ... ~ s ,s..-- ~ ,,.m 39'N 85'W 84'W 83'W 82'W 81'W 80'\\ e
N
- 9/E 4r 50
$k'( > k' t h contour interval 100 ni !I jN j / 0 40 80 120 160 KM J b o svJnm CA {gQD N -xx \\ Also Available On \\g Aperture Card L. 8 8 0 712 01i9 6 - di 'g PERRY HUCLEAR POWER PL ANT
- pnp THE CLEVELAND ELECTRIC ILLUulNATlHG COMPANY
,j 79'W 78'W Reduced to Pole Total Intensity Magnetic anomaly Map Upward Continued to 2.0 km FIGURE 3.7
i 44'N I O 1h . =. ~ nw m,e nA > u m ...~ . k) b'd 8 )hdM a .e rg ay hkf o?8 S#@hlf; Y W@ 6 lnhuh .,. ~ // 'bd) d bj 7 6 \\ 02 F %{.h 7J3 h I ey wh> Ns /kdfd 3 ) _ ~ ..~ WGMMM%{AW: 39'N 85'W 84'W 83'W 82'W 81'W 80'\\
JV 2 g ) .p /// yg e ( /of 8 Contour interval: 50 nT / l 0 40 80 120 160 KM y / Jo 9 maus c# CARD ~,, Also Available On s Aperture Card 8 8 () 71 9. 0 l ' O 'b ~ k 6 y PERRY HUCLE AR POWER PL ANT LLUM N AT,G COM A Y V 79'W 78'W Reduced to Pole Total Intensity Magnetic Anomaly Map Upward Continued to 5.0 km FIGURE 3.8
A e (.(- qv qu y e ,co / o h,? [ud u mp'b' bh x nm . 8. ~ > 1 uu p$ w v, W9d e uur x lo o c o 1 h ahh e ...~ ~ltdRdlf(r gewsrw k ... ~ n , n.b I ?Q)On 4 L O i%jf'. 8 Od d Ca kk e - r 6 %MS$I8A#2["g l 39 N as w 84.w 83.w 82 w 8, w 8o 3 7 l
N m/ N 3 n
- \\ '
y ?%6& 8)O Mg WW9 O ' CP y ( DG 8 di M th
- /
N Contour intervat 10 nT/Km ( 0 40 80 120 160 KM $,[ APE 1 URE CARD Aho Available On Aperture Card g J [ 8 8 0 712 01i9 8 - (h PERRY HUCLEAR POWER PL ANT THE CLEVELAND ELECTRIC ILLUMIN ATING COMP ANY f 79'W 78'W Vertical Derivative Reduced to Pole Total Intensity Magnetic Anomaly Map Upward continued to 5.0 km FIGURE 3.9 i _,_-__.r..
44*N Dhb b ,. w)m'cv s e, y b 42'N ~ ko/ b 4,.N BE$iMK8 mzma 39'N ^ 85'W 84'W 83'W 82'W 81'W 80'k '~ '-
/ m C% C 'o AM N -'W W f )' h / 'y^ MC O Contour intervat 0.2mGal/Km g
- g 0
40 80 120 160 KM ./ I I I i s ( Tl Q APERT M o CbEO ra f 419o Available On o g#g Aperture Card Td/ W /g 8807120196-([ PERRY NUCLEAR POWER PLANT LLUM N ATING COMPA Y Vertical Derivative Bouguer Gravity b' 79'W 78'W Anomaly Map Upward Continued to 5.0 km FIGURE 3.10 r"
44*N 5 . e ,an,2 42'N \\ PEMe%@M 41*N %,. am / 39'N ~ 85'W 84'W 83'W 82'W 81'W 80 - - ~
l y oA 1) d (' d$d () ' ;&P asi id: Oc48!' i / o ,?? l \\y m e Q
- l i
s D' / COntouf intervat 0.2 f Og / ? 7 170 m 120 i p ); 'l O T1 Us APEllTU11E CAllD Also Available On Aperture Card 8807120198'l ,Q PERRY HUCLE AR POWER PL ANT LLUM NAT H CouPANY 'l 79*W 75'w Internal Corres ndence Ana sis Co to Pole Total Intensity Magnetic Anomaly and vertical Derivative of Gravity Up d Continued FIGURE 3 L
.. s. E SM?%ENE ~~ MBF M ) U 19, )? ~ .- l FV /
- 0
(./ ' s o.s (( o p, c. C Ab5')[9 Ifi\\ ,wlle nt y / o w6 'l / o 7 t "'o Ys&}% 8 p l 0; d c i ,g. .o i ~ / \\ o.S' o l E 7 057 /* ]!Mk [ l p g;GC) r Vggc D w)
- . o
) / s Q )M} '5/ 1 ff M j f k S ', lo .6 .s h i n- ?!E I x ' ",." wy (?7 mgeigw opm n ) 82'W 81*W O l - - ~
kk'I N ,UI A y po +l \\ - ; ( Yr' [ PM[ h Y 290 ,e' Contour intervat 0.5 mGal rwn 0 20 40 60 80 KM v en c / O AFE TRE ,G ), < cm ~ j N r I Also Available On / Aperture Card
- CcD, P6 //
8 8 o n 2 o 3,9 8 - ic; j / / PERRY HUCLEAR POWER PL ANT 80'W 79'30W THE CL vELAND EL TR1c U Ay g CupAHy Bandpass Filtered (20 - 40 km) Bouguer Gravity Anomaly Map FIGURE 3.12
44'N c L 3 o r/ \\ 74pp. g n$ N \\ ... ~ mppmgsm.,w<,a 42 N _l o [ ,afot h [ ohi9 2
- b
\\, 2 k(0 s n i ?< .: 9 a A{ 3 ( s Nk? kBES$'LD / k l.cfXq)gq%egge% b 4,.n k9 a nna#m me 39'N l 85'W 84'W 83'W 82'W 81'W 80'0
N 9 T-l I L J DMN Q " ~~ w e k. E l a qp J% (Wbk, a yo Contour intervat 100 nT f !L 0 40 80 120 160 KM A/ L I I I i - V// o// Jh'd I b PE 'URE A CARD / s% Aleo Available On \\ Aperture Card 88cwc-s-w ,/, y I PERRY NUCLE AR POWER PL ANT THE CLEVELAND ELECTRIC b.i ILLUM'N ATING COMP ANY Reduced to Pole Total Intensity / 79'W 78'W Magnetic Anornaly Map with Interpreted EMMB Lineaments FIGURE 3.13 l
,a / we nsma 1Y N a /d O .O ) \\ / )p NU p n,n l x / (ld IQ/4 J, ?s f Sc \\ d n y >w - p v; 1 hL Y M4h@ltrd/ 'N o.s M ( / a t 'rsyena'~mw ll5 / h /A k A 4 3 *y i -;cje 3 obry ( .p/n,nsY-N s /N v v v b g f b %.o l C\\ J' DBdREER 40'30'N 82*W 81 Y/ k
N W koff h i l{ \\ ) -? h // h% [ ) Q { F f j s bW H i / / kdoe Contour interval: 0.5 mGal l *' NYl[ As> 0 20 40 60 80 KM 3 I I I i i /*C ) s O APE 1 URE / )[ Y CARD
- 7 ',,.s
[ j ~ N C Alto Available On 'Yliperture Card P 88071201'96-9,l j/ Q PERRY NUCLE AR POWER PL ANT " CL L" 80iW 79 *30V/ LU NATiNo co Asy Datsdpass Filtered (20 - 40 km) Bouguer Gravity Anomaly Map with Interpreted EMMU Lineaments FIGURE 3.14 s~
,d 42*Nnasan n 8 FTMLM311 a_ ;,a Kun kc 3 1 y ? )$Y/hI 'f*' N wi 41'N ' / ^ E P' % J)g We lBA zR 3 %$f?dbd988b h 0 N j Inis -h f[kN[d$$ I MY5ddl@Mbl 82'W 81'W
N. Yf N 'fMd i V U. f to 4 \\ \\_. x p, ks 0 /A P h WJ s / Contour intervat 50 nT h Y/ ~ )/ ,p 0 20 40 60 80 KM t_ _ I I i r / O Appe MF, g / Og_ 7 CANO f ( (s[;! / Aleo Availabic Ou 0) Aperture Card l'q, ,t?,,/ 8807120106-RL "cq k T PERRY NUCLE AR POWER PL ANT 80'w 79 30w ( THE CLEVELAND ELECTRIC Reduced to Pole Total Intensity Magnetic Anomaly Map with Interpreted EMMB Lineaments FIGURE 3.15 7"
O I APPENDIX 3A DAT A SOURCES, COMPILATION, AND PROCESSING OF GEOPOTENTIAL DAT A O f l 4 I i l r i l l O i. l Weston Geophy9 col 1
Introduction s \\,) The objective of this program, the need to prepare high-wavenumber processed maps, and the modeling requirements over an extensive region of both the U.S. and Canada necessitated the preparation of gridded Bouguer gravity and magnetic anomaly data sets utilizing the highest quality data available. As a result numerous data sets were evaluated and the best data from each area was selected and compiled into consistent gridded data sets which have been processed by a wave number domain filtering. Bouquer Gravity Anomaly Map The Bouguer gravity anomaly map of northern and central Ohio covers not only the majority of Ohio, but portions of the states of Pennsylvania, Michigan and [ ' West Virginia and Lake Erie and segments of Lake Ontario, and the province of I ontario, Canada. The region covers the area between approximately 39.4 and 44 N latitude and 78.5 and 84.8 W longitude. The available gravity data (either in station or grid values) from this region which comprise five -s separate data sets were edited for erroneous and redundant values, merged into a single data set, converted to rectangular coordinates with U.S. Geological survey Lambert Conformal Conic Projection with 33 N and 45 N as standard parallels and 83 W as the central meridian, and interpolated on to a 2 km square grid using a minimum curvature computer code. The following Bouguer gravity anomaly data sets were used in the compilation: 1. Geological Survey of Canada gravity data files for: a) Lakes Erie and Ontario and b) adjacent U.S. and Canada. 2. Bouguer gravity anomaly values of Ohio used to prepare the U.S. Geological Survey Map GP-962 (Hildenbrand and Kucks, 1984). 3. Approximately 1,700 gravity stations obtained by Weston Geophysical (} Corporation in the Painesville (Leroy) Ohio area. V 1993J
- 1*
Wevon Geophyucol
4. National Geophysical Data Center Bouguer gravity anomaly station values of the following areas: a) between 42.5 -44 N 84 -85 W and b)between 39 -40 N. 78 -80 W. 5. A total of 10 values of the 4 km grid values over Lake St. Clair from a file used to prepare the U.S. Gravity Anomaly Map. All data were reduced using the GRS-1967 and the IG3N-1971. A density of 2.67 gm/cm was assumed for earth materials between the station and sea level. The following data were excluded during the editing of the data sets. Data set lb: Data excluded because of erroneous values indicated by visual interpolation of adjacent values or because station values are not provided: O V x km from 830W y km from equator value 459.78 4776.80 -(missing value) 504.05 4812.82 441.84 4841.59 415.24 4855.06 ~ 379.79 4853.30 -95.0 223.04 4743.27 201.96 4742.90 -98.16 123.18 4738.88 131.44 4739.14 -87.83 -24.61 4741.21 -44.13 4741.48 -19.12 4841.69 -22.61 4841.92 -91.97 414.59 4937.69 255.03 4859.17 268.47 4859.87 -115.12 411.30 5029.84 457.41 5033.09 -129.15 466.40 5076.55 466.37 5076.55 -81.79 483.87 4844.55 -97.16 (~T (ml L 1993J
- 2*
WWon Geophysrcol
Data Set 2: Duplicate stations with Data set la) were excluded, iV) All data of Data Sets 1 through 4 have an estimated accuracy of roughly 0.5 mGal or better. The contour pattern of the Bouguer gravity anomaly map indicates that a few stations may have greater errors because of isolated closed contours, but no additional proof is available and, therefore, these point values have been retained in the data set. The vast majority of the stations excluding those in the Great Lakes should have an accuracy of better than 0.1 mGal. Data from Data set 5 are potentially the least accurate because no observed values are available in Lake St. Clair. All 10 values of this data cet were determined by interpolation. Errors are estimated to be as large as 1.0 mGals. Total Intensity Magnetic Anomaly Map The total intensity msgnetic anomaly map was prepared for the study area in the same manner as the Bouguer gravity anomaly map. A total of five data sets were used: V 1. Lake Erie data acquired from the Geological Survey of Canada. The data were gridded at a 1.2 km spacing. No adjustments were made to this data set. 2. The 1 km grid data set used to prepare U.S. Ge> >1ogical Map GP-961 was decimated to 2 km. No adjustment was made to the data. Data holes near ~10, 4720 km and 4, 4730 km were filled with a visual nierage of -200 nT. 3. The 2 km spacing grid f rom the U.S. National Magnetic Anomaly Map was used from 200,_ X _400 km and 4650 _y_5120 kn sfter -350 nT were added to the data. 4. The data over Ontario and Lakes Ontario and Huron and adjacent regions were derived from the 2 km grid used to prepare the Magn. etic Anomaly Map of North America. A constant value of -50 nT was added 1993J
- 3*
Weston Geophysical _ _ _ _ _ _ _, _ _ = _
to this data set to minimize join problems with the adjacent V regions. However, minor problems remain in the join with the Michigan data. A small hole in this data set in southern Ontario was hand digitized at roughly 22 km spacing from a regional magnetic map of Ontario. These data sets were merged into a single data set and regridded at 2 km at locations registered with the Bouguct gravity anomaly grid. The resulting data set is superior tc the data set used to prepare the Magnetic Ancmaly Map of North America, especially in Ohio and in the joins between the data of the two countries. DATA PROCESSING Bouguer gravity and total intensity anomaly values were plotted for the entire study region at a reale of 1:1,000,000 and at 1:500,000 scale for the region of northeastern Ohio and adjacent Lake Erie surrounding the Leroy earthquake epicenter. The gridded data sets of both gravity and magnetic anomaly fields were converted by a FFT program to the wavenumber domain, processed by a variety of filters, and converted back to the space domain for plotting at 1:1,000,000 and 1:500,000 scales. Filters were employed to reduce the magnetic data to the pole (RTP), eliminating the distortion of the anomaly field caused by inclination of the earth's magnetic field. The data were also bandpass filtered to emphasize the anomalies in both data sets derived from the upper crust. Short-wavelength anomalies were focused upon by vertical and horizorital derivative filters. The horizontal derivative is also useful in localizing the margins of the anoresly sources. The longer wavelength anomalies were investigated with upward continuation filters and strike-reject and stril.e pass filters were used to emphasize anomaltes of particular strike direction, correlacion of anomalies was effected by determining the correlation coefficient of the linear relationship between the vertical gradient of gravity and the reduced-to-pole magnetic anomaly at a grid point using all values within a 20 km square window surrounding the grid point (Internal correspondence Analysis). The local favorability (or correlation) of the registered vertical 1993J
- 4*
Weston Geophysico'
l t gradient of gravity and tlie reduced-to pole (RTP) mcgnetic anomaly was determined on a grid point by grid point basis by adding the quotients of the RTP magnetic value divided by the standard deviation of all these values over the region and the quotient of the vertical gradient of gravity divided by its regional standard deviation. l A total of 73 different contour maps were prepared from the compiled and processed gravity and magnetic anomaly data. Only selected examples of these maps which illustrate critical points are reproduced although all maps were used in the interpretation process, copies of all maps are on file at Weston Geophysical corporation. i l + 1993J e 5* Weston Geophysg:ci
s N 4.0 SEISMOLOGICAL REVIEW (O - 4.1 Introduction In the period following the occurrence of the January 31, 1986 5.0) in Leroy Township, of northeastern Ohio. earthquake (m = big Dr.Y. Aggarwal prepared "at the request of the Ohio Citizens for Responsible Energy" (Aggarwal, 1987) a critical review of studies conducted, either 10 years ago during the Final Safety Analysis of-the petry Nuclear Power Plant or more recently during the 1986 detailed investigations of the Leroy earthquake. The Leroy earthquake was subject to more detailed observations and analysis by governmental agencies, university scientists, and public utilities (Borcherdt, 1986: Wesson and Nicholson, 1986, Nicholson I et al., 1988; Herrmann and Nguyen, 1986; Seeber, 1986; Talwani and Acree, 1986: Weston Geophysical, 1986 and 1987:), than any previous earthquakes in northeastern Ohio. Although a general consensus on seismic parameters was achieved, a question on the nature and specific cause still remains unanswered, as it does for most of the earthquakes of eastern North America. In an effort to shed new light on this question, the Aggarwal Report proposes a structural relationship (p. 14 of the Report to OCRE) between a selected group of historical earthquakes and a magnetic boundN' observed on an aeromagnetic map of Ohio by Hildenbrand and Kucks (1984). It is suggested that selected epicenters, taking into account their location uncertainty, form a NNE trending lineation, quite similar to the magnetic boundary which the Aggarwal Report assumes to represent a fault zone. From there, the report infers a causal relationship between the assumed fault zone and the selected epicenters, and on the basis of fault length, concludes that "a large earthquake potential is a realistic possibility", page 2 and page 25. O 1931J
- 50
- Weston Gecphyscal
Among the various recommendations made for additional research q V required to test the conclusions. (p. 25-26, item IV). the report calls for an attempt to reduce the location uncertainties of some historical earthquakes that occurred prior to 1980. In the following pages, additional work recently done in this context to complement Appendix 2D-D of the 1979 FSAR is described and interpreted. Conclusions are made and compared to those contained in the Aggarwal report. 4.1.1 Regional Seismicity Before addressing the specific earthquakes included in the proposed seismic lineation, a cumulative seismicity map with a 200-mile radius around the Perry Plant was prepared (Figure 4.1) so that the seismic activity in northeastern Ohio can be evaluated in the regional context. All events with magnitude equal to or greater than 1.0 or intensity equal to or greater than 1(MM) have been included. The filled symbols correspond to those epicenters considered parts of "the strong alignment" suggested by the Aggarwal Report (page 19). In Figure 4.2, earthquakes within a 50-mile radius have been identified by dates of origin for reference. From Figure 4.1, it can be seen that the Ohio historical seismicity is made up mostly of small events, with intensities III and IV or magnitudes in the 3.0 to 4.0 range, often calculated from felt areas by Nutt11 (1979). From this low historical seismic background, one prominent cluster stands out in the Anna region, where a few intensities reach VII and VII-VIII, and magnitudes 4.5 to 4.9 m In
- addition, a
fairly concentrated broad zone of big. epicenters, can be seen in an east-west band in northwestern New York which crosses into Ontario along the Niagara Peninsula. It includes the Attica, New York 1929 earthquake, associated with the north-south trending clarendon-Linden fault. As reported in the 1988 Updated Safety Analysis Report (USAR), the northeastern Ohio q quadrant is dominated by the Leroy event of January 31, 1986 V 1931J
- 51 e 1
l wc9on Geophy9COI l
5.0) and the March 9. 1943 (m 4.5) events, both with (m = a blg w I = VI and V respectively. The observed seismicity has been superimposed on Reduced to Pole magnetics. (See Figure 4.3). Considered within the framework of northeastern United States and Canada, the level of seis:aicity in Ohio, is only nederate. No causal relationship of earthquakes to known structures have been identified, with the exceptions of La Malbaie, Quebec. Attica. New York, and Anna, Ohio. 4.1.2 Correlation Between Maqnetics and Seismicity The existence of a sharp change in the character, i.e. dominant wave length and intensity, of the magnetic anomalies in Central Ohio, has been noted since 1984 and named the AMB for Akron Magnetic Boundary. Yet neither its geologic nature nor its seismogenic potential have been clearly defined. Nonetheless, researchers have (]/ [ noted that several earthquakes have occurred in its general proximity (EPRI 1984). After the 1986 Leroy earthquake, seeber (1986), h ton C:cphysical (1986), and Seeber and Armbruster (1988), commented on the spatial relationship of the epicenter with the AMB. They pointed out that several historical events. taking into account their location t.ncertainties, could be grouped in a broad linear
- trend, parallel to or superimposed on the AMB.
The possibility of a causal link was entertained, but was not proven decisively. Spatial coincidence between epicenters and geological features or geophysical anomalies is frequently observed in seismotectonic studies; in fact, it is common practice to look for a spatial correlation. It is harder to support a causal relationship because spatial coicidence does not necessarily imply or prove the causal relationship. Most magnetic and gravity anomalies are asoismic, and generally earthquakes occur in the absence of specific anomalies. Those observations illustrate the danger of making a spatial correlation the only requisite of a causal link, e b w/ t 1931J
- 52
- i we9on Geophy9 cal
o In the present case, it is necessary to examine in detail the integrity of the proposed seismic lineation and estimate objectively the importance of each of the component earthquakes. Similarly, the spatial delineation of the AMB needs to be clearly established, without any prejudicial reference to the spatial extent of the seismic lineament, with which it is to be correlated. Furthermore, a reacona'aly complete analysis of possible structural features and lithological properties capable of generating the observed anomalous signatures must be made and modeled before their seismogenic potential can be defined. Only -after this analysis can the probability of causal relationship between a structure and the seismicity be logically advanced. This type of analysis has been conducted by CEI. 4.2 Re-Evaluation of Specific Epicenters i The proposed NNE alignment of earthquakes with an approximate length of ~10 km, in the vicinity of the AMB. is made up of four groups of epicenters. 1. Two events in 1983 2. The 1986 Leroy earthquake The 1943 and 1951 earthquakes 3. The two ' Aurora' 1955 earthquakes 4. Three events, near Akron, in 1885. 1932 and 1940 These selected earthquakes differ substantially in their location accuracy, e.g. from 0.5 to 16 km., and size, e.g. magnitude 5.0 down to 2.3. Using equal size symbols is misleading. For this rearon. on Figures 4.1 and 4.2. relative scaling has been used. It is particularly important to note that the quality of the data set is very inhomogeneous. O 1931J e 53
- Westen Geophy9 Col
4.2.1 The 1983 Earthquakes v These events were previously relocated, as part of Weston Geophysical's post January 31. 1986 earthquake studies (Weston. 1986) 4.2.2 The January 31, 1986 Earthquake, This event was analysed in a thorough manner, as referred in the Introduction (Section 4.1). 4.2.3 The December 3. 1951 Earthquake The following information was obtained for further analysis: 1. Twenty four questionnaires sent to postmasters or police chiefs by Rev. H. Birkenhauer, of John Carroll University, immediately af ter the shock. They were used to complement newspaper data already available. Figure 4.4 presents the distribution of all available felt reports. 2. Correspondence of Rev. Birkenhauer with J. T. Wilson of the University of Michigan, at Ann Arbor, with E. 1.. Sulkowski of the University of pittsburgh, and A. C. McTighe of Canisius College, in Buffalo, reveals that the earthquake was definitely not recorded at these closest observatories. Respective epicentral listances are estimated at 210. 180 and 260 km. 3. Seismograms from John Carroll were re-examined by several experienced seismologists. Rev. W. Ott of John Carroll kindly made available originals and enlarged photographs. Figure 4.5 shows the three components, reproduced from the enlargements. The vertical component was recorded at 30 m/mia while the horizontal components was 60 mm/ min. j O 1951J
- 54
- Weston Gecrysical
o 4.2.3.1 piscussion of the 1951 Earthquake U l. The felt reports collected ' indicate a felt area confined to a narrow rectangular band, almost 5 miles in width and 20 miles in length, along the lake shore, extending from Bratenahl to Fainesville, and with Willoughby near the center. This is new information: in Appendix 2D-D (1979), it was assumed that the earthquake had not been felt in Cleveland or Painesville, since the cleveland News and the Painesville Telegraph had not mentioned any local effects but only stressed the reports from the Willoughby area. A repeated quote from a communique to the press by Rev. Birkenhauer refers to a weakness of some sort below Willoughby. In addition. Rev. Birkenhauer cent a notice for publication in the Bulletin of the Seismological Society of America, 1951: "Willoughby. Ohio - December 3. 1951. The John carroll University seismologiul observatory reports an earthquake nineteen miles northeast of the station, which was felt at Willoughby. Chio and nearby villages. No damage caused." l i It is probably on the basis of this note that the "U. S. {. Earthquake - 1951" publication (1953) referred to Willoughby as l the epicenter. The Earthquake History of the United States (1973) simply omitted the event: Smith (1962) was first to attach the geographical coordinates of Willoughby to this event: Docekal (1970) and Nuttli (1979) did the same. In Appendix 2D-D of the FSAR (1979), the same coordinates were kept but an uncertainty of 15 miles adjud. Page 17 of the Aggarwal Report states that Weston used only a 15 km epicentral distance, and refers to his Figure 6. In j Appendix 2D-D. Weston states clearly that the epicentral coordinates are 41.65W and 81.41W. the same as those of Willoughby: this corresponds to 20.6 km from John Carroll 1931J
- $5
- Wepon Geophysical
/~T University, assuming the John Carroll station coordinates to be 41.489N and 81.b32E (Poppe, 1979). On the other hand, the report is correct in stating that the Weston location does not correspond to the 30 km or 19 miles that Rev. Birkenhauer refers to in his note. The reason for this difference: Weston (1979) did not find the S-P interval clear enough to support by itself a new relocated epicenter; Weston also assumed that Rev. Birkenhauer was aware of the discrepancy but could not resolve it clearly. In view of the information recently reviewed, confirming that felt reports similar to those observed at Willoughby, about IV(MM), extend to Mentor and Mentor-on-the-Lake, located almost 30 km from the station, one might wish to relocate the epicenter from Willoughby to a location in the Mentor region. This might seem more correct but would not guarantee a better accuracy as the possibility of an offshore epicentral location exists and is quite compatible with the observed intensities along the shore. Within this scenario, if one insists in placing the epicenter on the arc segment drawn with a 19-mile epicentral radius, a Mentor relocation would need a location uncertainty that increases with the distance from the shore line. In this case, the original Willoughby location, with an uncertainty of 15 to 8 miles remains equally adequate. Appendix 2.D-D proposed an epicentral area, not an epicentral point. 2. The John Carroll University seismugrams (Figure 4.5) reveal a rather short duration, 40 seconds at the most, equivalent to 3 l magnitude Mc = 2.0, Normally events of this size are not well recorded at distances beyond 200 km: this is in agreement with the negative answers received from Ann Arbor, MI, Pittsburgh. pA, and Buffalo, NY. l Usually, magnitude 2 earthquakes are not felt unless some I special factors come into play. It is believed that the soil amplification due to soft and saturated alluvial material along 1931J
- 56
- Weston Geophysical
p the shore is responsible for such a small event, propetly identifiable as a micro-earthquake, being felt ovar a 4 restricted area. The m = 3.2 derived from the total felt blg area relationship and associated with this event in the Nuttli (1979) catalog appears to be anomalously high compared to the observed 40 sec duration. A duration of 160 see is required for a Mc = 3.2. It is hard to explain this large discrepancy, even with differences of instrumentation. Most likely, the magnitude was smaller than previously inferred from the anomalous felt area. A magnitude 2.6 might be a good compromise, correcting for the instrumentation. References in the felt reports to a similarity with a "furnace exploding" support a small event. with a short duration due to the proximity of the epicentes. 1 4.2.3.2 Summary of 1951 Event The December 3, 1951 event was most likely a small event, possibly larger than Mc = 2.0 calculated on the basis of duration observed on John Carroll University seismograms, but less than 3.2 calculated from felt area. A compromise of 2.6 is suggested. The epicentral distance calculated by Rev. Birkenhauer from the S-P interval was 19 miles (30 km) and the northeast direction reported was surely based on felt reports and not on first motion observed on seisungrams. Although an emphasis on the felt reports from Willoughby was interpreted at the time as a suggested epicenter. it appears from a review of intensity data collected by questionnaires. that other
- towns, in particular Mentor and Mentor-on-the-Lake experienced sim!lar effects.
These locations would be in better agreement with the calculated 19 miles distance. Yet, an offshore epicenter is equally realistic and would explain the observed felt + data; such a case makes the selection of Willoughby and Mentor equally inaccurate. 1931J
- 57 +
We9on Gecphy9 Col
Considering the distribution of the towns where the event was not () felt, it seems unlikely that the true epicenter was further inland in a ESE direction from Willoughby as suggested by Aggarwal. 4.2.4 The May 26 and June 29. 1955 Ear _t_hquakes Although the two evaluations contained in Appendix 2D-D of the FSAR (1979) seemed satisfactorily complete, an effort was made to acquire additional information. 1. First, Rev. V. Ott of John Carroll Observatory was contacted; enlargements of seismograms for these earthquakes and copies of related correspondence files were kindly provided. 2. Dr. Anne Stevens of the Geological Survey of Canada was contacted, and her expert opinion solicited to resolve ambiguities in reported phase arrivals. 3. Dr. Shelton Alexander. Chairman of the Pennsylvania State i University Geoscience Department, was also contacted for L similar purpose. P.S.U. operates the State College, PA (SCP) station. Unt'ortunately, prior to 1962 when WSSN instrumentation was installed. SCP operated seismographs mostly suitable for the recording of long period waves. The 1955 events were not recorded. 4. Weston Observatory of Boston College, MA, was sisited and original seismograms examined; expert opinion of Dr. John Ebel was also obtained. I 4.2.4.1 Discussion of the 1955 Events i 1. Among the new information were the questionnaires sent and l received by Dr. Ed Walter of John Carroll immediately after the i ' O 1931J
- 58
- Wesbn Geophysicol
-r two earthquakes. Postmasters and police chiefs are the usual preparers. These questionnaires contained information more specific to locations than the newspaper reports where particular observations, such as "rattling windows, slight
- shaking, explosion-like noises, distant rumble " etc.
are applied generically to a list of towns. A large portion of the . questionnaires have simple negative answers: not felt here, not reported by anyone, no effect, etc." This type of negative information is ex*,romely useful in delineating the felt area more accurately: it is seldom mentioned in newspapers. For the May 26 event. 48 questionnaires were sent. 37 returned; for the June 29 event, 32 were sent and 21 returned. Pooling all the information available. Figures 4.6 and 4.7 were prepared as a complement or revision of Figures 15 and 16 of Appendix 2D-D. The felt reports from the two earthc29akes are very similar, both in content and distribution. They correspond to the lower range of the Mercalli scale, with intensities III, III-IV, and IV. For each event, there may be one or two reports in the IV-V range. leaving the contouring of isoseismals practically impossible, or too subjective. Cenparing felt areas is probably more objective and informative. 1 In Appendix 2D-D. Prepared mostly on the basis of newspapers
- data, the May event had been attributed an IV-V.
I, = IV given to the June event. slightly higher than the 1 = The basis of this choice was weak: for the May tremor. there was one case of a ,1! reporting a cracked window and one house where pictures fell uCf the wall, one reporter had also given his subjective evaauation that the June event was unlike the May event, since there was no report of "crying babies and bouncing refrigerators." A common set of epicentral coordinates, slightly northwest of Aurora had been chosen as 1931J
- 59 e Weston Geophyucal
the best compromise, and no meizoseismal had been contoured for b) lack of sufficient data. The general area of Aurora, suggested y by Dr. Walter of John Carroll University as the probable I epicenter, had been given full consideration and merit. It r should be noted that a 13 mile radius arc corresponding to an epicentral distance estimated from an S-P interval of 2.2 seconds passes close to the point where the four affected counties meet just northwest of Autora. At this time, after a review of the questionnaires and some seismograms from distant stations, there is no reason to change the common epicenter, but there is a basis to consider the June 29 event as probably larger than the May 26 tremer. The questionnaires for the May 26 tremor show nothing higher that Intensity IV. in Bedford. Solon. Geauga Lake, and Chagrin Falls. For the June 29 event. Geauga Lake reports a IV-V. "f rightened some." In the John Carroll University Bulletin. it is stated that field investigation carried out after each event revealed that "sanding of well" was observed in Portage County for the June event. The John Carroll University seismograms are reproduced in Figures 4.8. 4.9. and 4.10. Clearly, some resolution is lost with each copying, but an examination of the original data confirms an almost complete wipe-out of the trace after its sharp beginning. This wipe-out makes it dif ficult to identify the S arrival time with confidence. As a ecnsequence, a large epicentral uncertainty must remain in these two cases. The suggestion that the John Carroll instrumental data provide constraints on the epicenter inferred from the felt data is too simplistic, since only one station is available and the recordings are of poor quality. Figures 4.8. 4.9 and 4.10 do suggest a similarity although not perfect, between the two earthquakes. O 1931J
- 60
- Weston Geophysical
q Examination of seismograms from Ottawa and Kirkland Lake, iC's ontario confirm that the second event is marginally larger than the first one in May (Dr. A. Stevens, private communication). The examination of Weston Observatory's seismograms supports the same conclusion. Only the June 29 event has a faint Lg phase recorded. (Figure 4.11). while the May 26 event was absolutely not recorded. All of these recordings are too poor to allow a good coda magnitude estimate: yet Dr. Stevens, using amplitude of Lg and en approximated magnificatiori level for the Ottawa instruments, suggests a m magnitude of about 3.5. big or slightly larger, for the June 29 earthquake. In addition. Dr. Stevens has been able to calculate a rough epicentral solution us$ng the most reliable phases obtained from four stations: it confirms that a location in the general stea routheast of Cleveland is probably correct. Her analysis of the data has also led to the removal of event No. 654, from Smith's catalog. This event was initially placed northwest of ( Toronto, with an origin time of one minute af ter the reported \\ ohio June 29 origin time. She has also inferred an error of one minute in the origin time printed in the Cleveland newspapers in 1955, a point confirmed by Rev. Ott. The origin time included in Appendix 2D-D was correct. 4.2.4.2 Summary cf 1955 Events Additional research on these two earthquakes confirms that the epicentral at aas are common. most likely in the vicinity of Aurora. Ohio, with a 10-mile uncertainty. The felt areas of the two earthquakes are now delineated with greater confidence due to new information from the files of John carroll University observatory. The maximum felt intensity seems to be IV for the May 26 events, and IV-V for the June 29 event. just the reverse of what had been 1931J
- 61
- Wepon Geophyscal
suggested ten years ago. The few consulted seismograms from di'. tent m stations confirm that the second event was indeed larger, possibly 3.6. The May 26 event could then be assigned a with M = c M = 3.4. c 4.2.5 The March 9. 1943 Earthquake In the Aggarwal Report, it is stated that the 1943 event should be relocated using the 1986 Leroy earthquake as a master event, and that the inclusion of th< John Carroll station would be useful for this purpose. This suggestion has been examined carefully and found unrealistic. The joint epicentral determination (JED) method is a valuable technique when sufficient data is available. By referring to the ISS bulletin for 1943, one can easily find the data used by the ISS for locating the event. and by Dewey and Gordon (19*18) for relocating it, with a more appropriate geological model. Table 4.1 O shows 12 stations contributing data. Of these. 9 have been closed v much Lefore the 1985 earthquake, and no comparison can thus be made. Most of the closed stations belong to th Jesuit seismological Association; one to the Canadian observatories and one to Harvard University. The John Carroll station seismogram has been reproduced in Appendix 2D-D: with a drum speed of 12 mm/ min and no time control, it can not be paired with the 1986 John Carroll University seismogram obtained from a modern system. In Weston's opinion, the relocation by Dewey and Gordon was and remains the best improvement possible their calculated uncertainty (14 km) will not likely be reduced. Weston has nonetheless attempted to uncover new information. One finding consists of three short period seismograms for the 1943 event from Weston Observatory, and one short period vertical for the 1986 event. Recording of horizontal components has been discontinued. Although the 1943 and 1986 seismographs are not the O 1931J e 62 e Weston Geoohysicc u
same, they are comparable. Unfortunately, a storm of microseisms makes the 1943 data eFtremely noisy (Figure 4,12), and prevents any accurate phase picking. At best, the pair of records was used to confirm, as expected, a certain resemblance of the two signals. Trace wipe-outs make the Lg phase unreadable. The approximated coda 5.0; for the duration for the 1986 event gives a magnitude M = c 19(3, a coda magnitude of 4.4 is obtained from the noisy vertical. very close to the expected range (4.5 - 4.*1). 4.2.5.1 Summary of the 1943 Earthquake The suggestion for a JED is well-intentioned but not feasible, since the majority of the stations operating in 1943 have been closed. From the Weston Observatory records, one can find a general support for the present nearby epicentral locations and estimated magnitudes. 4.2.6 The Akron Earthquakes (1885. 1932. 1940) At the southern end of the earthquake alignment suggested by Dr. Aggarwal. there are three historical earthquakes of various importance and credibility. All of them have been discussed in Appendix 2D-D. and no additional information is available. Some comments are still in order. 1. The January 18. 1885 is the most significant of these events, since it was the most widely felt, although no damage ever occurred anywhere. Its nature remains mysterious, particularly because in several reports one finds conflicting references as to the ti.ne or number of shocks, and a possible cont ection to frost is mentioned. It appears somewhat strange that an earthquake would af fect distant localities with oto.it the same intensity, but net show a more definite center. Temperature conditions, which sometimes can be judged favorable to frost quakes, are not available. 1931J
- 63
- Wevon Geophy9 col
Although this event was relocated in 19*19 by Weston and the intensity increased from II to IV. it still remains a small event, with a large location uncertainty, and preferably with no magnitude assigned. 2. The January 21, 1932 event was felt only in e very restricted neighborhood on the shore of Summit Lake in Akron. The Intensity IV. reportedly observed, is not consirtent with the size of felt area. A possible shallow focal depth can explain this discrepancy. Explicit questioning of the true tectonic nature of the event remains without answer; a connection with a frost quake would. explain both localized effect and shallow depth. 3. on May 31. 1940, a "slight tremor" was felt by a few in Akron. The Intensity II and coordinates chosen by Bradley and Bennet have been kept. No additional information could be found in the newspapers. 4.2.6.1 Sununary of the Akron Events The most southern point of the seismic lineation proposed in the Aggarwal Report is based on two historical events only, near Akron, with no instrumental constraint but with scae mysterious a characteristics. Of the three repot ted tremors. only one in 1885, has a felt area that includes more than one town. Given the uncertain nature of these eva.ts located at the most southern end of the earthquake alignment, it seems that their inc'usion weakens the hypothesis more than it helps it, since the length of the assumed singular fault capable of generating large earthquakes is extended on the basis of poor data, j 1931J e 64 e i Weston Ge@ySCO! l
P l 4.3 general Discussion on the Seismic Alignment I From the data presented above, includin'g the basic references mentioned, it seems that the theory of a seismic alignment c.aused by i a single structure revealed by the magnetic - data -is a personal interpretation.' The. validity of the Aggarwal Report's conclusion that a potential for large earthquakes in the 6.5 magnitude ' range exists should be evaluated not only on the quality of the data. but on the degree of subjectivity in interpretation, particularly in view of the brief discussion presented and the current understanding of what the AMB represents. The report considers as established j that the AMB is an expression of a continuous fault zone, which eventually is <tssumed to be the equivalent of "a major active fault" (page 24). In this reasoning, spatial coincidence seems necessarily interpreted an implying a causal relationship. This type of spatial correlation is often made in empirical sciences, particularly in.the testing or early modeling stages of an experiment, but it is usually understood that the assumed causality relationship 'is only a ~~ hypothesis that needs to be tested. l I If the spatial coincidence of a seismie lineation with a sharp I contrast of the magnetic character of residuals is put aside i momentarily, other interesting scenarios or hypotheses can be entertained.
- First, the treatment of the geology included in this report j
illustrates in detail the high complexity of the subsurface lithologies resulting from a long history of deformation. often [ j under northwesterly forces. Pervasive joilting. in both NE and W f i direction, and interspersed zones of ductile shear surely affect [ large parts of the upper crust. In this review. the concept of f intersecting features as sources of enhanced stress and thus l earthquakes is sufficiently supported by observational data to be ) given equal consideration as an alternate seismogenic model to the extended singular fault. ( 1931J e 65 e f l Weston Geophysical {
- Secondly, the detailed investigations of the geopotential data gU support the geological analysis of the historical evolution of the upper crust.
Modeling along selected profiles suggests that the crustal region under investigation can be represented as an l-assemblage of many rock units of diverse shapes and dimensions with their own anomalous signatures. Local stress concentration is l possible at some of these multiple boundaries. Thirdly, an examination of the entire observed seismicity, including recent instrumental data, suggests that the distribution of both historical and recent events is not adequately accounted for by the single fault model suggested in the Aggarwal Report. On the other hand, the low seismic background with only several clusters or groups of events, including those with very small magnitudes. could be explained satisfactorily by the intersection model. In this
- model, the north-northeast trend of the Eastern Midcontinent Magnetic Belt (EMMB). is preserved, but the emphasis is put on the multiplicity of smaller cross-trending faults and zones of weakness revealed by the discontinuous anomaly pattern, with only few intersections being seismogenic.
1931J
- 66
- Wedon Geophy9 col
4.4 Feferences Aggarwal. Y.P., 1987. Seismicity and tectonic structure in Northeastern Ohio: Implications for earthquake hazard to the Perry Nuclear Power Plant. Report to Ohio Citizens for Responsible Energy. Inc., 28 pp. Borcherdt. R.D., 1986. Preliminary report on aftershock sequence for earthquake of January 31, 1986, near Painesville. Ohio, U.S.G.S Open-Pile report 86-181. Coffman. J.L., and von Hake. C.A.. 1973. Earthquake History of the United States. Pub.No.41-1. U.S. Dept of Commerce /N.O.A.A.. Boulder. CO. Dewey, J.W. and Gordon. D.W., 1984, Map showing recomputed hypocenters of earthquakes in the Eastern and Central United ('T States and adjacent Canada. 1925-1980. MFS MF-1699. U.S. '~') \\ Geological Survey. Department of the Interior. Docekal. Jerry. 1970. Earthquakes of the Stable Interior, with Dtphasis on the Midcontinent: University of Nebraska rh.D. Thesis 332 p. Electrical Power Research Institute, 1986. Seismic Hazard Methology for the Central and Eastern United States. Final Report. 10 vol. NP-4726. Herrmann. R.B. and Nguyen. B.V.. 1986. Focal mechanism studies of the January 31. 1986. Perry. Ohio, earthquake. Abstracts of the 58th annual meeting of the Eastern Section of the Seismological Society of America.
- p. 32.
v 1931J
- 67
- Weston Geophysical
Hildenbrand. T.G. and I:ucks. R. P. 1984. Residual total intensity . w) magnetic map of Ohio: U.S. Geological Survey Geophysical Investigations Map GP-961. Scale 1:500.000. Nicholson. C.. Roeloffs. E. and Wesson. R.L., 1988. The Northeastern Ohio earthquake of January 31. 1986: Was it induced?. Bulletin of the Seismological Society of America, vol 78. pp. 188-217. l Nuttli. O.W., 1979. Seismicity of the central United States, i l Geological Society of America. Reviews in Engineering Geology. i Vol. IV, pp. 67-93. Poppe. B.B., 1979. Historical Survey of U.S. Seismograph Stations. USGS Prof. Paper 1096. 389 p. Seeber. L., The January 11. 1986 Earthquake near Chardon Ohio arid its significance for the Perry Nuclear PoWr Plant and for Earthquake Hazard in the Eastern U.S.. Testimony before subcommittee on Energy and Environment. U.S. House of Rep., Washington D.C.. April 18. 1986. Seeber. L. and Armbruster. J.G. 1988. Recent and historic seismicity l in Northeastern Ohio: Reactivation of Precambrian faults and the role of fluid injection. Prelim. Rpt. to US NRC. Smith. W.E.T. 1966. Earthquakes of Eastern Canada and Adjacent Areas. 1928 - 1959: Publications cf the Dominion Observatory. V. 32. No. 3. Department of Mines and Technical Surveys. Ottawa. Canada. 115 p. Talwani. P. and Acree. S., 1986. Deep well injection at the Calhio wells and the Leroy. Ohio, carthquake of January 31, 1986. A report to the Clevelar:d Electric Illuminating Co.. Cleveland. Ohio. 92 p. I 1931J
- 68
- r I
Weston Geophysco!
U.S. Department of Commetce, 1953. United States Earthquakes-1951 Serial No. *162.. by L. Murphy and W.K. Cloud. 49 p. Wesson. R.L. and Nicholson. C.. 1986, Studies of the January 31. 1986. Northeastern Ohio earthqucke: A report to the U.S. Nuclear Regulatory Commission. U.S. Geological Survey Open-File Report 86-331, 131 p. Weston Geophysical Corp., 1979. Evaluation of Local Seinmicity around the Perry Nuclear power plant Site. Appendix D. FSAR. prepared for Cleveland Electric Illuminating Co. Weston Geophysical Corp. 1986. Investigations of confirmatory seismological and geological issues. Northeastern Ohio earthquake of January 31.
- 1986, prepared for Clevelend Illuminating Co.
Weston Geophysical Corp. 1987. Quarterly progress reports. CEI O Seismic Monitoring Network. Numbers 1.2.3 and 4. O 1931J
- 69
- Weston Geophyscol
M 4 ,s ,t 4 i ( i 1 i 1 1 b l I I i 4 i I FIGURES i d l d i .I { l a l I 1 t h { t I r i a ? l 6 Westor. Gecphysicol r
~ [,., 86._ .mc ,7 q / / / / .) / O / / \\ l / /,a~ ~ ~ ~ ~. / / O / e / e$ i e g i / 's / I 9 e N a I l I l / + f 1. l / Ie O I PtPP / O / i e ( n O e N O e' ( ) DOS [ 5 e 0. m\\- \\ s .I + . \\ \\ o \\ \\ Q 3 0 8' s g e s e ~~ ~ 0. M\\ 10 s 's as m o N s e \\ i 9 d 's b l O a ? O s e 3 s . O 'sc C e e N s ',o ~ O 200.+M1 9 W a O. b r e B e N o m e e /k
p l l-77 + 4G Y PA L s. s, s N w s. % : s \\ N-b p* ._ s. e > x. e. . q n .' \\ N LEGEND
- \\
o g MAculfp0C RANCES FROM 1 0 TO 40.0 I INf(NSlff RANCES FROM 1 f0 X11 I, flME WIWDOW SEclus IF00 ' ENDS 1998 -\\ MACN!TUDE INTENSITT \\ g g s ist a 3 0 ] l l 0 O 3 i e L I T o I. I ~ % i i l l l s i / / O / f 0 So 100 / / i a a e a _1 i i 5/ SCALE N HALES i T1 APERTURE e O CARD i g / i j Also Available On j g i Aperture Card o e i ,e g 8 8 0 712 01i9 5 - RD O PERRY NUCLE AR POWER PL ANT j j spN THE CLEYkLANC (LECTRIC O ILLUWIN A)(NG COMP ANY g e ' 38 Cumulative Seismicity l g M 61.0 Io 1 I 200-mile radius PNPP FIGURE 4.1 i I L
(, 83* + 0 + 0 C e.D -c l / r} / / 1. ( 'm / O O I prep ? I gf 9 \\ 4/10/1858 g 2l28/87 a' Q* E \\ /12/03/51 a g \\ g \\ 5/26/55gg e 6/29/55 N 0 8/ h S0. M-s, h ~~ ) + E'
e O LEGEND - s N MACN1TUDE RANGES FROM 1.0 TO 10 0 N INTENSlff RANCES FROM i TO Xll O \\ flME WIN 00il BECINS 1700 ENDS 1988 \\ s MAGNITUDE INTENSITY s e in h c 3 0 + y- 'T O O 't e I 9 til 22/83 o l Q Tl 1/8/ l D/86 El APERTURE CABD o \\ / / "/ Also Available On $31/88 / ' Aperture Card i 19 Y 5/85 / i SCALE N MLES y- ) 8807120196- @ M PERRY NUCLEAR power PL ANT (pNpp THE CLEVELAND (LECTRIC ILLUWIN ATING COWP ANY cumulative seismicity M 2 1.0 Io 1 1 50-mile radius PNPP PIGURE 4.2
1 w ~ {' i j/ . vgg/.g{d,..._, ;;7 p,@j g< y 'pj@ ) i i,4 c tr) f.2 u b_ .j-3p-/ fa i ~-O,- e. e t tv r-- u j 1 r 'i f)sf w,.. - Ut kb M5{ff==* j'\\.Ny d}r L.f? f ,.) , ^;, f^"5O7,4"J.'."[Ey.iT/' $ *MlL% :: d V')^,.-fi's " [ ^ W i{ .. V5 6;^ $' z-i r . ? ^ $[ is Y N.; 's 4o* 1. f '.. ( '- fQ G Oi ,.,. p&.., v.;J)l,llGg:(')} g r' f, Q, j,y'
- f L'*3 C',N i. p' $g*$,1,-j O-,
~m 2/ .y s s q 4 l *. ) 2 f'isi ' f'j, f (1 d W NO!3 --J-Y v '^'a b ~- ;N E ~ 24J AhM; %' @ 7 'k i C @ ^ W %*" ~ " 6 " \\ 42*N r 'Efiljy Y f)-pf [ j. ,(_ f s lp[' o& ffgJ d-y = N' ) )Y ',j';, < ::~&(7" lll\\, (i &g j., j y lL l 'kj$ E ~$) -4 ( 1 _ \\ \\ 5 /',' T4 Ski @hL,nnvn DN*C c y b.mgqwyz p p 41 *N / { b' O 'h fb '\\ ... +,7 h,. ' s ))[ - pp,a -Cm Y A - [ 4 ~.. - r ~ 'N i 1) '\\ 4 } 4)hW7%y gL Og 6 1 w) [/ :[(m I'i1 4 ic j G', Rj o Tk ?[^ ~ .h
- y;g
,"*-' g h 40'30'N - y fff 7d Q rv_' p s 'gh I %{. ? - :;# W' ~ o \\
- c' t,vM.G o a;\\
7, q . (,Jw}l - Q w) d 82*W 81*W i 8L' .~ 1
~ m 1 O{'d,. [Q w%yfj,t; w ~ y // N?? ?pn(($b. (D J %% o ) '.isi L i.w LEGEND r k NAmtlfu0C RANGES FA0t' -5.0 TO 80 0 .Ig (NIENSlff RANCES FRou l 10 Ilt. (, s D \\ flNE WIN 00tt SEGINS 15(4 (WOS 2000 h .t) /j naast rung iers.sier f g@g w, O / / i C b ' 'd +
- f t, h (
T g eni f .f 3 ( l IS$/', 2' // L N / //A ( ' '?{j, 7 I Contour intervat 50 nT s y, e )f[ 0 20 40 60 80 KM f f f f I i / ./ O_ TI
- v /
T 7 c
- 3.,;A 17 '
O APERTURE CARD U ,/0/i. . /! [& I (w) Aperture Card W Also Available On /- l ( 0 a ,}l \\
- hh 8 8 0 712 o 1,8 8 - a6 s
a t___ \\. I PERRY NUCLE AR POWER PL ANT 80'W 79'30w N THE CLEVELAND ELECTRIC ILLUMINATir40 COMPANY Cumulative seismicity and Reduced to Pole Magnetics Northeastern Ohio area FIGURE 4.3
P ( L AKE ERIE cP' O O L-O o o L-.. c' ' k-1 g _ __J _ _4 j i i J 1 1 1 L3 _.a (~. - f-t I" %
-m / l 9 r- - i J r-l _. J o / T1 o APERTURE .o CARD l l 1
- Felt Also Avellable On A crture Card P
s o Not Felt i e i O 10 2,0 miles w_,,, s t i J l I I ji 8 8 0 712 0149 6 'Alo l PERRY HUCLEAR POWER PLANT DNob THE CLEVELAND ELECTRIC { l 0- 'v ILLUMINATING COMPANY J m.. j Felt Report Map December 3, 1951 ,- 1,. 4 I J s i r \\s FIGURE 4.4
\\ y = :.- 7 : =, ; : :, =,, = _ : l L,, _ _ _ _..p. ..( - r- - >y Bluf'utfif%ss. ~ ~ a ~ ,bf, ~ g, ,g g m I / .. ?. r.n, - f+a,...2 _L g_e 7._3 -~g n 7y my,m gn,,, y < j e DEC 3,1951 Z . m w- - y , - - y m.. n-( m ..ww ,r-m- - -- -w -
w-
.a.L ,r- _a y.--_-- p_ as- - a ..,x. w.__ .u, tu.- py,,,, n n -
- p. -
<r y- - -- ~ _ _. _ m A 4 a m a ad - 2 -.c ., m..,gy- ~ _I,._ _ 7_ m = 4~ V F "MP T F - 'N7 y-- ,-pg =,, y 'r P" i- . _ ~3 gg ,- vr. _,o _ a m m_ y ,m s O__ A-.. y
- 5. _.
-m ,, -,g, s - w -,w-- .- y' l DEC 3,1951 NS __ _ x p_ x. y -_ m W~w { 7 g- _._x__ biblin x._ p sent ,, ~ _ - ~ ~ f- ^ inuseduquefbufttuguftung sp i nu ~ an k 8 n y, _ - _.. A, uuc A o_ _ _ - m, -.- A- .'M g4 Mpg DEC 3,1951 EW PERRY HUCLE AR POWER PLANT (Q ) ANpp THE CLEVELAND ELECYRIC ILLUMIN ATING COMPANY w John Carroll Observatory Seismograms December 3, 1991 I l FIGURE 4.5 /
f L AKE ERIE 4 l G' CP O O C I l l j I p O v! O O I O L_q ._+ (~- O 00 o o, y O. i ~ ~ ~ O O O O f r _ __J O l ..__J i l e l i i i J I t t 1 Lq _..J F- [. ,I i W '-8
N i ~ _J r-- TI _J o APERTURE o 1 CARD Nw Available On s -J Aperture Card e Felt l o Not Felt g l 0 10 2,0 miles i. t i i -. _J l i 8 8 0 'i 12 01 > 9 6 - a 7 z, O' f l g' PERRY HUCLEAR POWER PL ANT (pnp THE CLEVELAND ELECTRIC 4 8 e a Q. ILLUMINATING COMPANY i L.. ~j - ~ 1.s [ ~ <>. Pe1t Report P,ap May 26, 1955 I !_. J 3 PIGURE 4.6
I..s L AKE ERIE 47cf P 4 e, e' O e. e 'l e i 0 O i (- --o-. O a O O O i ~ -e-O i F i O (- p-1 1 f ) I. I 3 1 I I t l _.q -] _...J p-( r. p t W ar%
l 7 s l p-. i o _. _.] TI APERTUltE ~ j l CARD 0 Also Available on Aperture Card
- Felt o Not Felt o
l 0 to 20 miles t l .J l i i 6 8 0 712 0 lie 6 - 23 x, o' l r-- PERRY HUCLEAR POWER PLANT f ( THE CLEVELAHo ELECTRIC
- o.
iLLuwiH AtiNo CouPANY i L.- l ~' 1 --[ "',<i Felt Report Map l June 29, 1955 s f' ' j \\ g 3 \\ FIGURE 4.7
m:.
- ::,- :::::, ^ =^. - ::. ::._ : W ^ ^ - - ^ ^-
^ - ^ ^ * ~ ",f%'t:4 ir. l' ~L--- ^ --r ,.m
- . ^f-[;.'^g" fQ^u- _x ;^
n n: :,:.:::::: ::- no., m;;;;; - : y- , e. y-- .____-r . - --. w -vv N w-- 77-w '""'N N'T U "- w v T v- -w y w ,,7.- -, - m __ _ _ w --- 7 j..,,,,.
- . m
. b
- ^.
^^z^. ^;-'; -* ^^^^:: ^-^ ^
- -^-
,.....).'yyy%Ap' ^'M;:,,1:;5@y.9.;;y; - ;::.::,=,_.::.v; =. y:.f .: =,. = :.e,s w . ni ,:=.= = = 4 ,~ p %e &,.$ <?lth i 2 3 4 5 6 7 m 48.* (4.9+fd MAY 26,1955 EW = m_... a .x. c+- = =_=: _ -_ c -- w x. = .= g+ M
- a
_ g'= __ .anummuunu e . m.augn s s w y.y...ww,,w=;;q:g_.r y 3 o m s 1 ^ A RR Y "*M% ^ ^ L :' ^ ^- 3 \\ p ad' '*m**, 7 _ - g v.g -_-C (F:' d C' u_ _ _- a y _._ JUNE 29,1955 EW PERRY NUCLE AR POWER PL ANT IANpb THE CLEVELAND ELECTRIC v ILLUMINATING COMPANY John Carroll observatory Seismograms May 26, 1955 and June 29, 1955 East-West Component FIGURE 4.8 [
i oGL,, + 'L E Q y _ -^----t_m - __ __ ^y ^___f_C- ^g m __ - ; : g - --_m .- - - -- :.=--:r- _ -
- _ =
o.4',v.,***:.*,,,m w "- ' - - - ^-
- = -
--^ : : g,-
^^ --
^ ^^ ^ - - -^ ^ m,,.- i e'; 1 2. 3 4 5 6 7 8 a MAY 26,1955 Z O ~. l s l =,. .. :,. wwm;i.. g g-y { A E M J ff?tf 1. _ O_ O t_ 7_-.- _.. - - -. - = JUNE 29,1955 2 l l I PERRY NUCLEAR POWER PL ANT Np ~ THE CLEVELAND ELfCTRIC lLLUMINATING COMPANY John Carroll Observatory l Seismograms May 26, 1955 and June 29, 1955 vertical coroponent FIGURE 4.9
t 1 1 4 ,. e :::= =: = := -
- =_w-= =
- = ::=:::.,
f
- y. ;.
- v4m+,se:: :.v:::_,=.-
-== w=.vmw::e:=,v:::m:::;:,:= l
- _ =- :, ::.: :=: :n;_x:i.x::. :::z=: :;::: ::::: ::, :=::
- .=e_
- =v:<,== e
- =_._ ~ ::,,;:-
- =:: --==
- =_._ ~ ::,,;:-
- =v:<,== e
^ ^#f:. ^r,'A^.^ -,^," J.^ - ^^:J ^ -^.,^. ^. ?,' ^:: ,"v^,- ^ ^/- ^. ^- ^ ^_^.^g':i.^,'. " ^ ^ ^^.'-
- [,\\^,^-,."_C
^^ ^' 4 :: :, .=r:::n'.4', =,'l:en ^::::: ^ '::::::: : ^^:::.':/,"=.Q':.^,%^:::^:.:^ ^ ',v,"::-,w _._::, _.._ _ ^--., - ^ ^;^:^ : ^ ^ ^ : ; :',,, - -.^ ' " ^ ^ ^ ^: L ^: -^ ^:.'Q'-^ ',^ '^ ^ ^ ^':-^i.7,^^-~,","; '^ ^, ?- l ^ ^ ' ^ ^ ^ ^ ^
- ,v
- r ::. c; ^^ '- --W6%=//,WMV/,': -t:s,wnes%a*%p up;;;. z!.',sswM4wwv:::::-
.-l::.';: : J::: :,:. : ^ :lg.,': - * ^:: ^ n:.,
- .:: :: ',':ll.-'.
6;',u..v.w y, w w w r==:x p.-: = : w : w w--::=:=.u,w ::,=:-%v)w 1 1 METRIC 1 i 2 3 4 5 6 7 8 9 MAY 26,1955 NS I 1 mw.. . _ - = :
- _ =
m .-w - __-_o- ,.-y ~ -- ,,-y -W-w m-v w w W w ~ yw y_ v ._.-_.w.."i_ __ _. _.. =: w w v_.w-w w w g w vV T_ 1^_-___--- ^ ^^ -m ___-__m R_ __v' _ met _ _ _ _ l ! _A J _. ___m. ^^^^^^*--,w ,, _.,, 7 r w _.m a JL a i. '_ _ A u.. __ __ l ',',T. .m ,,1,.,.,,,,..-,_, .-n amnuunnun . maunno as=====aanv===WmQu h a d4 e a e i e e e a e a e a t u a e a u a e a u4 e a e e e a eo e a a a a a e a n a s e a a p u a e a ,u s uo g,,ea aeanioea qi p"'upuunnuwnhemmenson """"******'""*%Muunmoonasun nuinuu nnanmu l gmanns3====g g aq mis .uggsaghesame r^ r-r JUNE 29,1955 NS g PERRY MUCLE AR POWER PL ANT (ANpp THE CLEVELAND ELECT 0C ILLUulN ATlHG COMP ANY y.s John Carroll Observatory Seismograms May 26, 1955 and June 29, 1955 North-South component FIGURE 4.10
) ( l\\ c, N@ CCZm i.@U0 I 1 Lg
- i.
{ t \\, J i, l l I l 'I I I N P I-W g I I 1 l Y g U p, I i< g I g I-e re t l I h i ) H l I { l T h i I, R L I, 1 g l, ) A y, ' i i, l ( 1, l i g g E y l ? l t 4 i l N i ' 'l i g '( i W r g 'g O I l
- 'r., ng=, ~;'
l< 3 i
- =
i 3 g s l 8[ D ,i Ig l 'i g l I wf l
- i i
I y j l n l [ l I q' l i, I / l D l 'q l ,'j R o ,i il l i O i n l'j C l o f j E !g f R. c i I i l4 D- 'I ) e fl l O7 n t I 9 - i I R I o I 1 c r.f E I n ) i P-i e 'y '3-e T e 1 R g i -. r O i [ r ,t E g H 't p. g n r t 'l o e S u 1 e ) l S i i I i k 4 L i ii ,i!' ' t - .!g e i lL 1
'11 N APERTURE CARD 1hr 20 min Aho Available On Aperture Cer I r% L L v) x q tt, j t ~__ q lij g, (A ~ - - ~2 = 2 m,,,, ~,,,,, _ C--tN 21 T,l,, r_, x_ r_f s_ g
- _~
~ _c 3 -u-x c c_- a c-- w e_ e f-o o \\ ~ ~ 5 ~ c a w c. k c e o r _a y) h-1 Weston Observatory, Mass. 88071201'9b ,2.9 PERRY NUCLEAR POWER PLANT (ANp THE CLEVELAND ELECT AIC ILLUMINATING COMPANY Veston Observatory, June 29, 1955 Seismograms lh 21m FIGURE 4.11 . - - - - ~
- ~ " '
Laf g.. ~ Xff ' W.* RlpVGQQ ~ jT-? * ~ v~ Q .n . -mu t ,h"Mi ' ~* w Ay w&x r.; , JW WgWW ^ ft k& ,w ~ 'w T s n A s s, N '.~ h k = r, m V!5 m.
- N y
6%vg -obg
== yv m % h. '( ~ a%va., r e s.sww N w. &p I ff a w e fi@ em+ ~n 3.u W N "m .e 4 'A.A [ MIk J v W'd
- )
,(g e. t Wh y,4 .~ ,S 'hda. r w \\' ^N N Q ,3 l w.// '. s.Y'-).. N jy;,,,"x[. 6 v e -a w'.i W i.. p$%ff'kfb' cf u ~'b. d y c, &} QQ'," 'A. v* " ( -V .v. ~ w h o <\\Wm \\
- ^
g q~~'~%' s%(Qtssy**>gh'.h, bgg.7 bv sq E b,7M ' + 6 Lc, ~,.e.; p * ,Q g p r w s a < e.' g[4 9v.}4h^ @S.C(? Q p v y ~/' 4C ~ sr w.[Ob h ( D,/v'i - W g-U
- k*
'\\/ s '^ C' QlQc.w-n' a s VEc*'s./,W v.g/ V.WY'r@t.*,ABY8 *,. v, v Wr'.VT?,W@I ? - Awsrs es ,i YA.w
- '4. Wv.'?
..... /ad Weston Observatory, Massachusetts 1 ' ~ ' -
Af A A w w "Y ^' i A Ys~. '~ ~ &( ~ ~ x n... %eN. d w, s e. J s \\ \\ e 3 N/ = ....,,,4. ... g.,,. 'f w +. W n /A.s 9 A / w s_. f. 'a-d g ^ 'At A-V k' Gr \\ 'Ym l A, h$a ~ g .g y,. a /,a, .* W.a // mV/ .e %
- / M V
i D it .y..s.t.... f4 ^ ..m. 's PERRY HUCLEAR POWER PL ANT ,ks yr (({ THE CLEVELAND ELECTRIC pNo w ILLUMIN ATING COMPANY p.g }{ {} Weston observatory. March 9, 1944 Seismograms ^I Alm Avsih.h1c On Aperture Card FIGURE 4.12 8807120li96-3d ~,
-a I i P e b 4 TABLE 1 1 A A d I 4 l I t I i I F i d Weston Geophysical ---,--o,,----- w -w-er m - a-~.w -,.wwa-m-e-r-e-
- s e l l l n,.ll 3n.ea-va.vev. ll.ev.e cele.s -evgl -ee9l -.ll-jegll ,.a a .iel.v- ~. ~...,-.- m ~~~n. oi IIL di II iii lE attih IloEE illiE StI5i IE st tilit E tE ltjihl '. l l .s e s z x S o. s ,t g' g . a 8 4.... m .n....- 4 o. s nn. ..s n n n o n.. _.,.. l..l-n .I-la. 11 ,i ; a. - l......, l l.o., e. 1-.!.,..I g _o_._.. i ." a a.en _.,, ..ln.n..n .-z,.. nlnr,. z11,3 -1:sI :2.tgn 2 ,,w.i
- e. i. =. ~ _ e - _
1* i4>,. ++i -i i.i.. A ..4, i *-i + -.i.+, ++iii ,+ .,e.n. 4=,..-. ...._.--..,... A e.,- _.,.l ~...n ..l ~...,4.11.. l.o.o.l . e -- u,,.. .n A m *a; w......, s,-- -,, .....,.,..4.4 i u. ,e. x .... e t u v. a.-- _._- _ _n. -,I-...n-.- .--.. 1 - ( _.._ -.....3 a. I,.. I.,.,. r .g -S x-LAj A 4" l 4> g ig ["i+its 2 sist+ * * +
- b "A
AL I ++ &l 8o f as
- ...... n g.,.-
- 4 g A a,..,.. o.
a,. s... -.. _. _. - _. l.. _..._ _. _ o. 4.,. l..l.. ._.l .,e,.. A..u-o - g. n o - ; l _,. l. w. e -a,4 s, j....,.s..,., 1,,i.x. _, a: 5as = 3, _,# a._._._... ........~........_...A - -.....-..... -..-. , nnnnn....._.. e _... --- --. - -.~ ~~ *- eunuo...-- ~ .n 3y. nn --- ~_-- n nn en n n n n 4 W .W 4a.e. n.I _g. -],s. s 4 ....n ...m... .e.e.ee e.... n.... 4 e.. ee.e.e.e. .9..e.ees -.e. see,a -..A ..e.see. 3333 -e e onen. 3 333 33 3- - : -) ; m..,.g a ,am a 7ss.2 4 = 1 =2 to3 -
- <s o
a a 3*3 2 a. .E, 3 M .c. st = 2 s.a=tal j ifdfi$13i)3 394t 45 A "1 !I 34 = Ili!e5El as . =,5 2! 3 2 2 4-3 25ji3 'E m = 1);xx$ s
- !IIjd
.s er.<< Ait'jj s! 223 E!3 4*EJ' }}$'e=Tj!litil}j!.-3 3 j E 1(esE *E = xx,=sjt as !l2eES" >l. t rM sc=3w c;x =* : 145 1 f a f a es n s-c- at e f-~x a. h d .Jat 3 l ! ! " *. mII:=3 i.2 =p3 .i e ,e sais7; g 4 o -s y e F sxx .f.g,. a} r .j =1,2e,4 8 r x 1 4 it1I 152A 1 l I l l.- .a. i n 4:yp*ia 2 g"']3 -5 E i i L'i s O s .s,I u g j=s: i 2a t. i i 3 s i! 9 Is t 4 i: ** R
- "j
-1; I t v a e'w! ae j gIlli- 's I 2 i s ya 2i 3s."7, a j$r. 2"8 wiiiji
- {.: ;
av '.t u e 1 xy;
- 2E i
d 3 e4:e a1s =.se,,, s .* 0 . cxa 2 2 w e 2 si, u .a. ~ s i '. l. a wasva a ex. xa e x n 25.=n '. _a.l g a s a s 2 2 4 n I a,..- ,s,r. .e.x.. t i n-ta. 4 = 1 -i j;. s :s = a-;J20' g a e3 ei , g.
- .s i
- e,. =a ~ <
re,
- i "*1.*l""
s;. 'a 3 m sse g = S e n ad-j. I. 3 a.,. il ] w" I :s '-*s y s 'I "5f2a a- "n t =..a1 = s -- = .; a} a . 4, a, 43*p.1-i r 2 se-
- e. a.
_a-e - x. s. g ~*, rA 1. -s=
- ==.=r,.
~> r .]a-xr.. =5 i!*2 a -i -a i.. g +- -r a 2 1.- ;
- t L.a
.ia 3".3 x i _& ". J. !.3 id as 1ai v d i3. g- +- i 5E"74'k ci,i 1..iisd2i.3vn's*x445id53$ 213j!.=l $ff$ $(# $# IdU 4 rs sf o. 2,4 2.x je. j ". 1 I a... < s a-. l.- a* e 1 i 2 =1 fd.s.. rw.=J N._ 3, x.g
- _r a.,
e%,. x io. 3 o .. s <. 2, y, g .- p..w(. ax...s o i s ..t a.j.i.s
- gay 3, 3
3-g u-i.* - ". 'M=, 2,1 j,i x 12 e =s2n x [-sJ s;.ig e j a. = x n:a a d ej u n ta x a ..E1 } w-xa F F - a ,2 :a" A n 2.L i s ri]al i " g siaa.( ?a rtsm s p.e a J i 5 *ca:- m, s s A *! ! s.FL ao ski:e., Jn s.2 .a
- -ij"
-,x d . j J g.lj0 I
- >3
=s s t24,1}*ns,jdj..a34*8 O
- 4'e....
v* N 4 j$1 A ;= -== ,j"i i y s_4 rJs i j.1. if::,x,jgf 0"s3x 7}.$. a i i sa.6 8 M s ssB } malig i i3.-ty j )ges 7xd #, wa* n:i "l l s8 2 _gg_52 ; 3",j ga. - M. 4,i iwe Exs;. i't:7 a t 'ggI8d;x,_'iyS*fraxr,x; y a! g . p.7 x,- -It!jlds 1GriEt2 1 1 I a 6 <a -3 t:i it %:1 37 3 il=1r?xei'3a -v -.... ,5 3 JMf1jsE j 3 m.i g".i;5s. !'=!?)*a.;2 3E Lgg1l"3 ggjlIGU ee.-y < Ji. it. d1'I ,., o = .a3se s s . >l [1 =14 - - 2 g ' ~- .= --a .g taajgys a' eji -3 a 2 gi gj -~ / 4L .u g g 1 1 = m-. 1}}