Named as one of six formations of Copper Basin Group (rank raised) for Scorpion Mountain 1 mi south of type section. Type section measured from SW1/4 NW1/4 sec 25, T4N, R21E to NE1/4 SE1/4 sec 19, T4N, R22E, Custer Co (Idaho Mountains province) and Blaine Co (Snake River basin), ID. Gradationally overlies Drummond Mine Limestone (new) of Copper Basin Group and gradationally underlies Muldoon Canyon Formation (new) of Copper Basin. Base placed where limestone is not dominant. Top defined where thin-bedded quartzite predominates. Is exposed discontinuously from T2N, R23E to at least T8N, R20E to northwest. Is 3,625 ft thick at type; thins to northwest (600 to 1,200 ft thick), and to south and southeast. Consists of medium- to dark-gray, chert-quartzite-argillite conglomerate interbedded with gray, very fine to coarse grained, moderately to well sorted quartzite. The lower 300-500 ft are very thin to thin-bedded quartzite interbedded with dark-gray argillite and some sandy limestone. Main part of formation is thick to very thick-bedded, channeled, weathers brown. Conglomerate clasts range from granules to boulders, mostly chert and quartzite. Amount of and size of conglomerate clasts decrease to south and southeast. No fossils found. Considered Upper Mississippian, "Chesteran." Nomenclature chart.

Source: GNU records (USGS DDS-6; Denver GNULEX).

Recognized as one of six formations of Copper Basin Group in central Pioneer Mountains, Custer Co, ID, Idaho Mountains province. Overlies Drummond Mine Limestone of Copper Basin; underlies Muldoon Canyon Formation of Copper Basin. Stratigraphic chart. Age modified from Upper Mississippian to Lower Mississippian. [Reason for age change not stated.]

Source: GNU records (USGS DDS-6; Denver GNULEX).

Rank reduced and assigned as lowermost of four members of newly named Argosy Creek Formation of Copper Basin Group (revised). Argosy Creek includes all units within Copper Basin Group above Drummond Mine Limestone: Scorpion Mountain, Muldoon Canyon, Brockie Lake Conglomerate, and Iron Bog Creek Members, all reduced from formation rank. Argosy Creek defined because upper part of Copper Basin Group is poorly exposed and abrupt facies changes make previous formation-rank units difficult to map. At type contains 1100 m of channelized turbidite and graded conglomerate. Occurs in Pioneer Mountains area, Blaine Co, south-central ID (Snake River basin). Unit occurs west of Copper Basin thrust fault. Measured section; geologic map (fig 4); correlation charts. Overlies Drummond Mine Limestone of Copper Basin Group; underlies Muldoon Canyon. Assigned Early Mississippian (Kinderhookian) age.

Source: GNU records (USGS DDS-6; Denver GNULEX).