ANTLER PEAK LIMESTONE

The Antler Peak Limestone is named for exposure on Antler Peak in T. 32 N., R 43 E., near Battle Mountain (Roberts, 1951).

The Antler Peak Limestone, the middle unit of the Antler Sequence, contains abundant fusulinids, corals, and brachiopods in the lower portion of the formation which indicate a Late Pennsylvanian and Early Permian (Missourian to Wolfcampian) age. Although there is no evidence for erosion, an apparent hiatus exists between the Battle Formation and Antler Peak Limestone with the Desmonian missing. This is correlative with the regional sub-Strathearn or Middle Pennsylvanian unconformity (Dott, 1955; Steele, 1960).

At its type section, the Antler Peak Limestone consists of 15 to 155 feet of medium to thick-bedded, light to dark gray and black limestone, with lenses and nodules of chert, and interbedded light grey to brown, shaly limestone and shale (Roberts, 1964b). Some of the limestones are clastic containing grains and pebbles of chert and quartzite derived from the Battle Formation. Shaly units tend to be concentrated in the lower portion of the formation.

In the Shoshone Range, the Antler Peak Limestone consists of light-gray, thick-bedded, fine to coarsely-granular, fossiliferous limestone with chert beds a few inches to 5 feet in thickness (Gilluly and Gates, 1965). A few thin interbeds of shaly and sandy, yellowish limestone are also present. Although considerably deformed, the Antler Peak conformably and apparently gradationally overlies the Battle Formation.

In the Toiyabe Range, the Antler Peak is a light to dark gray, fossiliferous limestone. The thickness of the Antler Peak is highly variable, and in fact the unit thins or pinches out entirely in several places (Stewart and McKee, 1977).

In the Owyhee Quadrangle, the Antler Peak Limestone is blue-gray to medium-gray, encrinal calcarenite with quartzite and limestone clasts, and minor amounts of interbedded gray to brown weathering siliceous limestone, and gray and red-weathering phyllite (Coats, 1971).

The Antler Peak Limestone is about 625 feet thick at the type section near Battle Mountain (Roberts, 1964b), 700 feet in the structurally complex Mount Lewis area of the Shoshone Range (Gilluly and Gates, 1965), and 100-300 feet in the Toiyabe Range (Stewart and McKee, 1977).

The Antler Peak Limestone is exposed in the Battle Mountain area, Toiyabe and Shoshone Ranges, and Owyhee Quadrangle.

Roberts (1964b) suggested a shallow marine origin for the Antler Peak Limestone. The Antler Peak probably represents tidal flat and delta margin sedimentation.