Geology of the South Fork of the Ogden River area, Weber County, Utah

The South Fork of the Ogden River area is in eastern Weber County , Utah approximately two miles east of the town of Huntsville and comprises a portion of the northcentral Wasatch Mountains. The rocks exposed in the area range in age from Pre- cambrian to Quaternary. The Precambrian consists of quart- zite, quartzitic sandstone, arkosite, and phyllite (10,000-feet) ; the Cambrian rocks are meta-quartzite', limestone, dolomite and shale (3500 feet); the Ordovician is limestone5 dolomite and shale (600+feet); the Silurian rocks are largely arenaceous dolomite (243- feet); the Devonian is dolomite, arenaceous limestone and dolomite, sandstone, and shale (1144 feet); the Mississippian system is represented largely by limestone and sandstone (3300- feet); the Pennsylvanian is limestone and sandstone. The Eocene Knight (?) formation, which once covered the entire area, is a cobble and boulder conglomerate with sandstone lenses; Quaternary deposits consist of Lake Bonneville sediments and alluvium. The Upper Cambrian and base of the Ordovician are not exposed in the area. The Paleozoic strata were found to correlate with the formations of the Logan auadrangle. Detailed measured sections are included. Except for minor disconformities, sedimentation was probably continuous from Precambrian to Pennsylvanian time. No evidence for an unconformity could be found at the base of the Cambrian. The area is located very near the southern limit of Ordovician and Silurian deposition; neither system is represented in the Uinta Mountains to the south. The most important structural feature of the area is a north-trending syncline. The trace of the Willard (?) thrust is believed to be exposed in the western part of the area near Ogden Valley.