The Mint Wash Granodiorite comprises the Mint Wash Pluton that has intruded into Paleoproterozoic sedimentary, metasedimentary, and metavolcanic rocks. On the northern end of Granite Mountain, these strata include weakly to moderately metamorphosed mudstone, siltstone, and fine-grained sandstone; basalt lava flows; ferruginous, white and dark laminated silica rock; infrequently laminated, epidote-silica rock; thinly interlayered silica and carbonate; laminated, highly platy, talc and/or pyrophyllite schist. Some of siliceous rock types are suspected of being primary chemical precipitates from Paleoproterozoic ocean water. The south end of the Mint Wash Pluton, has intruded into Paleoproterozoic mafic, metavolcanic rocks that include basalt lava flows and Paleoproterozoic intrusive rocks, hornblende-rich gabbro-norite, gabbro, and gabbro-diorite.