Named as 1 of 8 formations of the Dove Creek Group (new) for exposures in the highest parts of Mount Harrison in secs 4 and 9, T13S, R24E, Cassia Co, ID in the Great Basin province. No type locality designated. Present only on Mount Harrison in the Albion Range. [Geographic name for this unit may not appear on a topographic map.] Consists of massive quartzite; is divisible into a lower rusty-weathering half and an upper gray-weathering half. Is usually less pure and more irregularly bedded than the Elba Quartzite (new), basal formation of the Dove Creek Group. Has lenses of quartz pebble conglomerate and mica schist scattered throughout formation. Overlies the Cambrian and Ordovician Conner Creek Formation (new) of Dove Creek; underlies the Cambrian and Ordovician Land Creek Formation (new) of Dove Creek. Lower contact placed at top of last schist or carbonate below massive quartzite of Harrison Summit. Upper contact placed at base of lowest schist or carbonate above massive quartzite of Harrison Summit. Geologic map. Cambrian and Ordovician age.

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

Harrison Summit Quartzite. Sample collected in the NW/4 sec. 34, T. 11 S., R. 24 E., Mount Harrison 7.5-min quadrangle, Cassia County, Idaho. Metamorphic age 70.2 +/-2 Ma [Late Cretaceous] based on a radiometric (K-Ar; biotite and chlorite) determination.

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