is 170 feet thick. In the Eureka District of Nevada, 135 miles northwest of Pioche, this formation lies between the Prospect Mountain quartzitic sandstone and the great limestone series and is about 200 feet in thickness. In the House Range section, 105 miles north-northeast of Pioche, the formation is 125 feet thick. In the Big Cottonwood section of the Wasatch range, about 125 miles northeast of the House Range, near the old shore line, the Pioche formation is represented by the lower portion of the arenaceous shales which are here 250 feet in thickness. The Pioche formation horizon is next met with to the north where the line of the Canadian Pacific railroad crosses the Continental Divide. At this place the formation is called the Mount Whyte formation.
Organic Remains.—At all the localities mentioned except that of the House Range, where no fossils except annelid borings and trails have been found, the Lower Cambrian Olenellus fauna occurs.
Prospect Mountain Formation[1]
Type Locality.—Prospect Peak, Eureka District, Nevada.
Derivation.—From Prospect Peak, the type locality.
Character.—Gray to brown quartzitic sandstones.
Thickness.—At Prospect Peak, 1,500 feet. Estimated 1,200 feet on the western face of the House Range, Millard County, Utah, in the vicinity of Dome and Sinbad Canyons.
Organic Remains.—Annelid trails and trilobite tracks. Lower Cambrian in age.
- ↑ This formation was first named by Mr. Arnold Hague in 1882, in the Second Ann. Rept. U. S. Geol. Survey, p. 27, and defined in 1883, in the Third Ann. Rept. U. S. Geol. Survey, p. 254.
