Geology of the Upper Tick Canyon area, California

Abstract

The rocks of the upper Tick Canyon area comprise pre-Cretaceous crystalline complex (basement complex), the Oligocene (?) Vasquez formation, the Miocene Tick Canyon formation, the upper Miocene Mint Canyon formation, and Quaternary terrace deposits, alluvial fan material, and stream deposits. The oldest rocks are schists and gneisses, intruded by granitic rocks. The Vazquez formation, more than 4,000 feet thick, contains fanglomerates, arkosic sandstones, fine-grained lake deposits, and volcanic flows. It lies against or upon the rocks of the basement complex in places with fault contact and elsewhere with depositional contact. It dips steeply, and in places it is folded into anticlines and synclines that gently plunge south of west. It contains faults of predominantly strike-slip motion in northeasterly or northwesterly direction. The Tick Canyon formation consists of fine-grained arkosic sandstones and coarse-grained conglomerates. Its average thickness is about 600 feet. It lies with strong angular unconformity upon the eroded beds of the Vasquez formation. The Mint Canyon beds are coarse-textured fanglomerates with some interbedded finer-grained arkosic sandstones. The Mint Canyon formation is disconformable upon the beds of the Tick Canyon formation. The Tick Canyon and Mint Canyon formations dip moderately to the southwest and are slightly folded and faulted along lines of deformtion previously extablished during folding of the Vasquez rocks. Some of the structural features of the area may be related in origin to the San Andreas rift. There has been some mining in the area for gold and other metals and for borax and gypsum.