By: M. A. Shubat and M. A. Siders
Geologic mapping of the Silver Peak quadrangle focused on the volcanic stratigraphy, mineral resource potential, and structural geology. Pre-Tertiary rocks crop out in the quad rangle and record a brief marine invasion in Middle to Late Jurassic time, followed by continental sedimentation through out the Cretaceous. Tertiary volcanic rocks are the dominant lithology. Ash-flow tuffs of the Isom Formation, Quichapa roup, and Racer Canyon Tuff are the most voluminous products of calc-alkaline volcanism, and local rhyolite to dacite flows represent late Miocene bimodal volcanism. Structural events recorded in the quadrangle include Sevier-age thrusting, deformation related to mid-Miocene intrusion, and Neogene extensional tectonism. Middle to late Miocene extensional deformation produced west-northwest-trending folds, northwest-striking normal faults, strike-slip faults, and oblique-slip faults. Late Miocene to Quaternary basin-range style faulting produced as much as 9800 feet of offset along the western-bounding fault of the Antelope Range.
Pages: 13 p.
Plates: 2 pl.
Location: Iron County
Media Type: Paper Map