Middle Cambrian Stratigraphy of the House, Wah Wah, and Adjacent Ranges in Western Utah

Abstract

Geologic mapping and paleontologic evaluation of Middle Cambrian strata in western Utah have extended the usage of several formations first defined in the House Range by Walcott and have shown that new units are needed outside of the House Range for upper Middle Cambrian strata of different facies. The following usage is proposed for the House Range: Lower Cambrian — Prospect Mountain Quartzite and the lower member of the Pioche Formation; Middle Cambrian — Tatow Member of the Pioche Formation, Millard Member and upper members of the Howell Limestone, Chisholm Formation, Dome Limestone, Whirlwind Formation, Swasey Limestone, Wheeler Shale, Marjum Formation, and the lower part of the Weeks Limestone. New formations defined in the Wah Wah Mountains include the Eye of Needle Limestone (Wheeler Shale equivalent), Pierson Cove Formation (lower Marjum Formation equivalent), and the Wah Wah Summit Formation (Weeks Limestone near equivalent). The Trippe Limestone is extended from the Deep Creek Range into west-central Utah, and a new member, Fish Springs Member, is defined as a thin but widely mappable unit. The House Range contains the most continuously fossiliferous trilobite sequence, but most ranges in western Utah contain the following faunas: Albertella , Glossopleura , Ehmaniella , Ptychagnostus gibbus , Bathyuriscus fimbriatus , and Eldoradia .