Influence of stress-induced deformations on observed water flow in fractures at the Climax granitic stock
Three examples of stress-induced displacement influence on fracture-dominated hydrology were noted in drifts 1400 ft below surface in granite. Seepage into drifts was limited to portions of shears near a fault zone. No water entered the drifts from the fault itself, although its orientation relative to Basin and Range extension is favorable for fracture opening. Localization of seepage appears to result from excavation block motion that increased apertures of the shear zones in contrast to the fault where asperities had been destroyed by earlier shearing thus minimizing aperture increases. Seepage was also noted, in an adjoining drift, from a set of shallow-dip healed fractures that intersected the rib, and from vertical fractures that increased the crown. The restricted location of this seepage apparently was a result of shear opening of the joints that occurred because of cantilevered support of tabular rock between joints. Interpretation of paleostresses based on joint chronologies and orientations indicates that sets subjected to shear stresses at a time when normal stresses were low contained mineral infilling. Sets subjected to shear stresses at a time when the normal stresses were significant had minimal mineral infilling. 8 refs., 7 figs.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 60450
- Report Number(s):
- UCRL-95539-Rev.1; CONF-870625-19-Rev.1; ON: DE88008342
- Resource Relation:
- Conference: 28. U.S. symposium on rock mechanics, Tucson, AZ (United States), 29 Jun - 1 Jul 1987; Other Information: PBD: Jun 1987
- Country of Publication:
- United States
- Language:
- English
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