Petrologic Study of the Fox Hills Sandstone, Rock Springs Uplift, Wyoming

摘要

New petrographic data provide support for many earlier conclusions regarding the depositional history of the Fox Hills Sandstone, Rock Springs Uplift, Wyo., and also provide the basis for new interpretations. The presence of framework grains of primary dolomite, sedimentary structures, and coarsening-upward grain-size sequences supports a shallow-marine, regressive origin of the Fox Hills Sandstone. Detrital dolomite and limestone (rare) in conjunction with a large fraction of chert indicate that the source area provided a large volume of dolomite and limestone and was near enough to the depositional basin that small quantities of the carbonate rocks survived the transport. Moreover, numerous rock fragments consisting largely of shale, siltstone, and sandstone indicate that the Fox Hills Sandstone was derived from a sedimentary terrane that was probably in the vicinity of the Sevier orogenic belt to the west.