ML18220A785
| ML18220A785 | |
| Person / Time | |
|---|---|
| Site: | Clinch River |
| Issue date: | 08/08/2018 |
| From: | Gerry Stirewalt NRC/NRO/DLSE/RGSB |
| To: | |
| Stirewalt G | |
| Shared Package | |
| ML18220A749 | List: |
| References | |
| Download: ML18220A785 (4) | |
Text
CC-B2 CC-B1 MP-423 MP-101 Figure 1. Geologic cross-section K-K across the CRN Site showing locations of boreholes MP-101 and MP-423 that penetrate shear-fracture zones in rocks of the Chickamauga Group (i.e., the Rockdell Formation and the Eidson Member of the Lincolnshire Formation, respectively) and boreholes CC-B1 and CC-B2 that penetrate fault gouge associated with the Copper Creek thrust fault. (Figure from SSAR Figure 2.5.1-30.)
CALCITE VEINS BEDDING-PARALLEL STYLOLITES BEDDING CALCITE VEIN STYLOLITES AT HIGH ANGLES TO BEDDING Figure 2. Details of stylolites oriented parallel and at high angles to bedding in the shear-fracture zone penetrated in borehole MP-101. This shear-fracture zone occurs in the Rockdell Formation of the Chickamauga Group and underlies potential site Location A as shown in Figure 1. The center portion of this core was extracted from a depth between 248.1 and 250.6 ft below the ground surface. (Image by G. Stirewalt from January 2018.)
ROCK UNIT OUTSIDE THE FAULT ZONE WITHOUT CATACLASIS FAULT GOUGE PRODUCED BY MECHANICAL CRUSHING AND GRINDING (CATACLASIS) DUE TO FAULT DISPLACEMENT BEDDING Figure 3. Fault gouge associated with the Copper Creek fault penetrated in borehole CC-B2. The gouge, a product of mechanical crushing and grinding (i.e., cataclasis) related to thrust displacement along the fault dated at 279.5 +/- 11.3 Ma, occurs between the base of the Cambrian Rome Formation and the top of the stratigraphically younger Ordovician Moccasin Formation of the Chickamauga Group. The Rome Formation overlies the Moccasin because it was thrust over the Moccasin Formation along the fault. Thickness of gouge ranges from about 1.5-2.3 m (4.3-7.4 ft). The fault, located about 1 km (0.6 mi) southeast of the CRN Site, has a reported displacement of 12-50 km (7.4-31 mi). Regional thrust faults comparable to the Copper Creek fault in age and extent are characteristic of the Valley and Ridge physiographic province in which the CRN Site is located. (Image by G. Stirewalt from January 2018.)
VERTICAL JOINT WELL-DEVELOPED BEDDING PLANES SHOW RELATIVELY SHALLOW DIPS AT THIS LOCATION Figure 4. Entrance to Copper Ridge Cave, which occurs in carbonate rock of the Knox Group. Entrance geometry suggests epigenic, not hypogenic, dissolution processes formed the cave. This cave is located about 6 km (3.7 mi) east of the CRN Site. (Image by G. Stirewalt from January 2018.)