Siliciclastic Overlap Assemblage - Conglomerate, sandstone, siltstone, and limestone

Unit represents rocks that are stratigraphic sequences that include both Lower Permian and Pennsylvanian rocks, and also sections that have not been broken out regionally into younger and older Permian and Pennsylvanian units. The Antler sequence (Roberts, 1964) rocks are present in Humboldt and Lander Counties and include the Antler Peak Limestone, the Highway Limestone, the Battle Formation or Battle Conglomerate, and the Etchart Limestone. The Brock Canyon Formation of Permian or Pennsylvanian age is in the Cortez Mountains in Eureka County and the siliciclastic and carbonate Strathearn Formation is exposed in Elko County (Theodore, Moring, and others, 2003). Scattered remnants of conglomerate, sandstone, siltstone, and limestone in Nye County, and unnamed limestone and dolomite in Elko County are also included. In the northern Hot Creek Range in Nye County, PIPacl is faulted with lower Paleozoic Carbonate shelf sequence rocks. Additionally, Early Triassic fossils in the area have caused reassignment of some of the rocks to the Candelaria Formation (TRcl). In the Pancake Range, PIPacl lies on the Ely Limestone (IPMbc). In the Toquima Range, the Pennsylvanian Wildcat Peak Formation lies unconformably on Slope assemblage rocks (DOts). In the Monitor Range and in Lander County, this unit lies unconformably on the lower Paleozoic Basin assemblage rocks (DCs). At Battle Mountain the Antler sequence lies unconformably on both the Harmony Formation, which is the Dutch Flat terrane (DF), and the Valmy Formation of Basin assemblage unit DCs. At Edna Mountain near Golconda and in the Osgood Mountains it lies unconformably on Cambrian and Late Proterozoic quartzite (CZq) and Cambrian phyllite and shale (Ctd) of the Nolan belt, as well as on units of the Basin and Slope assemblages (DCs, DOts). In the Cortez Mountains of northern Eureka County, it lies unconformably on Basin and Slope assemblage rocks (DCs, DOts). In the Adobe Range and the Sulphur Spring Range, it lies unconformably on Pennsylvanian and Mississippian Foreland basin rocks (IPMcl) (Trexler, Cashman, and others, 2004). In northern Elko County in the Bull Run and Copper Mountains, it lies unconformably on strongly deformed Ordovician to Cambrian rocks of the Nolan belt (OCtd). In the Snake Mountains and the HD Range, the Pennsylvanian Quilici Formation lies unconformably on the Basin and Slope assemblages (DCs, DOts, Ss) and is unconformably overlain by the Permian Siliciclastic overlap assemblage rocks (Pacl). In far northeastern Nevada, upper Paleozoic rocks around Contact are very poorly known, but are similar to the Siliciclastic overlap assemblage rocks recognized in the HD range, and are thus included in this group.
State Nevada
Name Siliciclastic Overlap Assemblage - Conglomerate, sandstone, siltstone, and limestone
Geologic age Permian to Middle Pennsylvanian
Lithologic constituents
Sedimentary > Clastic > Conglomerate (Bed)
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Clastic > Siltstone (Bed)
Sedimentary > Carbonate > Dolostone (Bed)
Sedimentary > Carbonate > Limestone (Bed)
NGMDB product
Counties Elko - Eureka - Humboldt - Lander - Nye