SHEAR DEFORMATION OF NEVADA TEST SITE ROCKS: TESTS TO 60KB AND 900C.

Abstract : Six Nevada Test Site rocks were sheared in a large opposed anvil shear press to maximum pressures of 60 kb and maximum temperatures of 900C. The torsion tests on tuff, dolomite, shale, granodiorite, and quartzite were designed to determine shear strength and internal friction data for underground test media. The most significant result is weakening of the tuff caused by dehydration of associated zeolite alteration products. This weakening mechanism might occur near the shot point of nuclear tests in tuff where temperatures rise above the dehydration temperatures for zeolite. (Author)