Elastic moduli, thermal expansion, and inferred permeability of two granites to 350oC and 55 megapascals.

Abstract

The coefficient of thermal linear expansion alpha , Young's modulus E, and bulk modulus K have been determined for the Westerly and Stripa granites to temperatures T of 350oC and pressures P to 55MPa. Using conventional triaxial apparatus, displacement measurements were made on three samples from each of three orthogonal directions for both rocks. Comparison of the directional values at any P, T, and those from the 9-sample population indicated that within our precision, both granites are isotropic in E, K, and alpha . Both E and K for both rocks decreased with T and increased with P in a nonlinear fashion. From 19-350oC, E decreased by as much as a factor of 2 and K decreased by 2-3 times, depending on P. From 6-55MPa, E increased by factors of 3-6 and K increased by 3-5, depending on T.-Authors