Type location is north end of Spectre Spur, northeastern Soda Mountains [approximately 35 deg 18'30"N, 116 deg 13'30"W, Baker 15' quad] San Bernardino Co, CA where unit is most complete and least metamorphosed. Consists of thick series of volcanic flow breccia and sandstone ranging from massive andesite flows through flow breccia, pyroclastic rocks and welded tuff to volcanic sandstone and finally to nearly pure quartzite. Displays little bedding. Yellow, gray, red, purple and green colors common. Generally bound in complex fault-block relations by limestones of late Paleozoic age. Intruded by Late Mesozoic plutonic rocks. Estimated thickness is 7000 ft. At type disconformably overlies sedimentary rocks of Early Triassic age. No rocks known to overlie unit in mapped area of northern Soda Mountains [geologic map included in report]. On basis of field relations age is post-Early Triassic and pre-Cretaceous.

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

Sketch map shows name "Soda Mountains Formation" although text has "Soda Mountain Formation" (Grose, 1959). Overlies Moenkopi Formation. Is probably Middle to Late Triassic age.

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

Sketch map indicates following map units (descending): quartzite, hypabyssal intrusives, sandstone, tuff, and andesite (of Soda Mountain Formation). Conformably or disconformably overlies Silver Lake Formation (new). Age of Soda Mountain Formation probably ranges from Middle Triassic to Middle Jurassic because of its apparent conformity with Silver Lake Formation and presence of probable Jurassic quartzite in its upper part.

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