| Description |
The Cedar Mountains are in northwestern Utah in the northeastern part of the Basin and Range Province. The area mapped is about 60 miles west of Salt Lake City, Utah and includes an area of about 550 square miles. Sedimentary strata exposed in the Cedar Mountains range in age from Late Mississippian to Recent. No Mesozoic beds outcrop in the Cedar Mountains. The sedimentary rocks have been divided into 10 different formations with a total thickness in excess of 20,775 feet. The Paleozoic strata have a thickness of about 19,700 feet distributed among the systems as follows: Mississippian 5790+, Pennsylvanian 5695, Permian 8190+. Thickness, in feet, of the series of Permo-Pennsylvanian age are: Guadalupian, 652+; Leonardian, 4772; Wolfcampian, 2772; Virgilian, 2390; Missourian (?) 487; Des Moinesian, 1473; Morrowan- Atokan, 1345. Quartzose sandstone, medium and dark gray limestone, black shale, and quartzite are typical of the Mississippian strata. Overlying beds of the Oquirrh and ""Permian unnamed formation"" are composed of sandy, cherty, and bioclastic limestones, sandstones and quartzites. Mas¬sive limestone, dark gray, thin-and medium-bedded dolostone, chert and phosphate beds succeeded upward by yellow-brown and pink limestone constitute the highest units of the Paleozoic succession. A basal red conglomerate and a sandy, tuffaceous form¬ation constitute the early Tertiary sedimentary rocks and have an estimated minimum thickness of 1,100 feet. Unconsolidated deposits of alluvial gravel, lacustrine clay and sand and gravel, and eolian sand comprise the latest Tertiary and Quaternary materials. Folds, domal uplifts, thrust faults, high-angle reverse faults, strike-slip faults, transverse faults and block-faults constitute the more important structures recog¬nized in the Cedar Mountains. Folds, thrust faults, high- angle reverse faults and a strike-slip fault developed dur¬ing the Laramide Orogeny. Domal uplifts are probably relat¬ ed to intrusive activity and can only be dated as younger than folding of Early Laramide age. Transverse and block faults are features younger than early Tertiary basaltic andesite extrusives. Rhyolites, of probable intrusive origin, a basaltic andesite series and basalt comprise the igneous rocks of the Cedar Mountains. The rhyolite and the basaltic andesite series are considered to be of early Tertiary age while the basalt is probably of Miocene or Pliocene age. Probable source areas for part or all of the extrusive rocks are located within the area of the investigation. Vein deposits of aragonite, sand and gravel, and ground water have been of economic importance in the Cedar Mountains. Thin beds of phosphate rock in the west-central Cedar Mountains will not be of economic importance in the foreseeable future. |
