The Poorman Peak Formation is named for exposures along Poorman Peak, in Secs. 11 and 14, T. 44 N., R. 55 E., in the western portion of the Mount Velma Quadrangle in northern Elko County (Coash, 1967).

Although fossils recovered from the Poorman Peak suggest a possible age range from Late Mississippian to Late Pennsylvanian and/or Permian, the formation is provisionally assigned a Permian age (Coash, 1967). The Poorman Peak Formation conformably overlies the Hammond Canyon Formation and is conformably overlain by Triassic rocks in the Mount Velma Quadrangle (Coash, 1967).

The Poorman Peak Formation is a sequence of interbedded shale and chert, with lesser amounts of limestone which are locally sandy and conglomeratic. The fissile shales are black or green and are locally fossiliferous. The cherts are black and commonly alternate with shale in beds up to 1 foot in thickness. The gray limestones are concentrated in the upper few hundred feet of the formation and make up about 25 percent of the unit. The limestones are locally crinoidal and also contain thin beds of calcarenite and coarse-grained sub-angular impure sandstone with quartz, feldspar, sericitized muscovite, calcite and hematite (Coash, 1967). Sandstones near the top of the formation are locally up to 60 feet in thickness.

A faulted section of the Poorman Peak near the type section is 3,860 feet thick (Coash, 1967).

The Poorman Peak Formation is exposed in the Mount Velma Quadrangle (Coash, 1967) in northern Elko County. Depositional Setting

The depositional setting of the Poorman Peak Formation is very poorly understood. It may represent relatively shallow marine deltaic sedimentation similar to units within the Carlin Sequence.