Named as a member (1 of 5) of the Gothic Formation for exposures along west bank of Middle Brush Creek about 1/4 to 1/2 mi north of junction of Middle and East Brush Creek, sec 14, T13S, R85W, Gunnison Co, CO in the Piceance basin. These exposures designated the type locality. Is 278 ft thick at type where it is composed of gray, sandy, very thin bedded, calcareous siltstone, gray-red, very fine, fine-medium- to coarse-grained arkose, gray, massive ledge-forming limestone, and interbedded gray siltstone and shale. Arkose may be calcareous, micaceous. Fusulinids of Cherokee or Des Moinesian age in limestone beds. Overlies unnamed part of Gothic. Underlies Crystal River Siltstone Member (new) of Gothic, or Hot Springs Conglomerate Member (new) of Gothic, depending on locality. Cross section.

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