ABSTRACT: Stratigraphy, Sedimentation and Basin Analysis of the Permian Dollarhide Formation, Smoky Mountains, Central Idaho
The Dollarhide Formation is a fine-grained, carbonaceous, mixed siliciclastic-carbonate unit deposited in the southwestern part of the Pennsylvanian-Permian Wood River basin in the Smoky Mountains, west of Sun Valley, Idaho. The Dollarhide Formation is approximately 2000 m thick and is divided into lower, middle, and upper members. The lower and upper members are dark-colored argillites, siltstones, fine-grained sandstones, and sandy limestones, with lenticular conglomerates. The upper member is coarser-grained in comparison with the lower member. Sedimentary structures include incised channels and graded bedding.
The lower member represents an anoxic, middle and lower slope environment characterized by low-concentration sediment gravity flows. The middle member is lighter colored and represents channelized high-concentration sediment gravity flows in an upper slope environment. The upper member records a return to euxinic lower slope conditions.
The lower and upper members are thought to represent deposition during times of sea-level highstand (Virgilian and Wolfcampian, respectively) on a south-southeast-facing slope. The middle member is thought to represent lowstand siliciclastic and allodapic deposition resulting from an influx of cratonic quartz sand near the Virgilian-Wolfcampian stage boundary.
AAPG Search and Discovery Article #91002©1990 AAPG Rocky Mountain Section Meeting, Denver, Colorado, September 16-19, 1990