OF-08-12 Geologic Map of the Cameron Mountain Quadrangle, Chaffee, Park, and Fremont Counties, Colorado

The purpose of this map is to describe the geologic setting, mineral and ground-water resources, and geologic hazards of this 7.5-minute quadrangle located southwest of Denver in central Colorado. The original field work for this map was completed by C.A. Wallace and A. D. Lawson in 1997; this is the newly colorized version of the original Cameron Mountain map, Open File Report 98-04. Digital ZIP/PDF download. OF-08-12D

From the Author’s Notes:

The Cameron Mountain quadrangle is located in southeastern Chaffee County, southern Park County, and western Fremont County in the southern part of the Mosquito Range about 10 km north of Salida, Colorado. The map area includes rugged terrane along the western border, and high rolling hills and a high plateau in the central and eastern parts of the quadrangle. Elevations range from about 8,500 to 11,000 ft. The oldest rocks in the quadrangle are Proterozoic metamorphic and igneous rocks that are overlain unconformably by Paleozoic sedimentary rocks, Tertiary volcanic rocks, and Quaternary glaciofluvial, slope-wash, and stream deposits. The Late Cretaceous Whitehorn Granodiorite intruded Paleozoic sedimentary units. Steep faults offset Proterozoic and Paleozoic rocks. Late Cretaceous plutonic rocks are not offset by most faults and most faults a pre-Late Cretaceous in age. Tertiary volcanic rocks are composed mainly of silicic welded tuff and airfall tuff, and Tertiary sedimentary rocks are composed of silt, sand, and gravel.