Harney Peak Granite and associated pegmatites, Black Hills, South Dakota
The Harney Peak Granite is located in the south-central portion of the Precambrian core of the Black Hills, South Dakota. This field study includes five sites near Keystone, South Dakota (Figs. 1 and 2). All sites are accessible by passenger car. At Site 1, the Harney Peak Granite is exposed at the Mount Rushmore National Memorial. (Large groups visiting at Mount Rushmore are expected to check in at the memorial headquarters.) Hammers or sample collecting are not allowed at the Rushmore site. A suite of Harney Peak Granite maybe collected to the west of the memorial (Site la). Sites 2 through 5 are pegmatites (Diamond Mica, Etta, Peerless, and Dan Patch) associated with the Harney Peak Granite. Permission for access to the Etta pegmatite may be obtained from the Pacer Corporation, Box 912, Custer, South Dakota 57730 (605/673-4458). Permission for access to the Peerless pegmatite maybe obtained from the Rushmore Borglum Museum in Keystone, South Dakota (605/666-4449). The other sites are on public land.
Figures & Tables
Rocky Mountain Section of the Geological Society of America
One of six volumes generated by each GSA section for the Decade of North American Geology (DNAG) project, this Centennial Field Guide contains descriptions of 100 sites or site clusters representing outstanding geologic locations in northern Arizona, Colorado, Idaho, Montana, North Dakota, New Mexico, South Dakota, Utah, Wyoming, and Alberta.