The Elkhorn thrust is defined by the juxtaposition of Early and Middle Proterozoic metamorphic and igneous rocks against Mesozoic and Tertiary rocks. Within the mapped area, an imbricate frontal thrust system juxtaposes Upper Cretaceous rocks against Paleocene rocks of the South Park Formation. In the southeastern section of the quadrangle, Middle Proterozoic igneous rocks are thrust over the South Park Formation. Syntectonic conglomerates (Txc) are preserved both on the hanging wall and footwall of the Elkhorn thrust. North of the map area we have identified normal faulting of probable Quaternary age.
Additional publication details
USGS Numbered Series
Geologic Map of the Elkhorn Quadrangle, Park County, Colorado