Fluid-Rock Interactions in a Paleo-Geothermal Reservoir (Noble Hills Granite, California, USA). Part 2: The Influence of Fracturing on Granite Alteration Processes and Fluid Circulation at Low to Moderate Regional Strain

Fracture connectivity within fractured granitic basement geothermal reservoirs is an important factor controlling their permeability. This study aims to improve the understanding of fluid–rock interaction processes at low moderate regional strain. The Noble Hills range (Death Valley, CA, USA) was chosen as a naturally exhumed paleo reservoir. A series petrographic, petrophysical, and geochemical investigations, combined with fracture distribution analysis, were carried out on samples collected across zones. Our results indicate that several generations fluids have percolated through An increase (1) alteration degree; (2) porosity values; (3) calcite content observed when approaching No correlation identified among degree, porosity, or content. At local scale, showed degree does not necessarily depend density amount It concluded influence strain coeval drastically petrophysical properties zones, which in turn impact production potential.