Hornblende schist of Idaho Springs formation: intruded by pegmatite near Eldora. Boulder County, Colorado. Circa 1911.
Dates
Date Taken
1911
Summary
Hornblende schist of Idaho Springs formation: intruded by pegmatite near Eldora. Boulder County, Colorado. Circa 1911. Plate 12-B in U.S. Geological Survey Professional Paper 94. 1917.
Summary
Hornblende schist of Idaho Springs formation: intruded by pegmatite near Eldora. Boulder County, Colorado. Circa 1911.
Plate 12-B in U.S. Geological Survey Professional Paper 94. 1917.
This USGS product is considered to be in the U.S. public domain. For further information on the USGS Information Policies and Instructions, refer to the Copyrights and Credits section on this web page: http://www.usgs.gov/laws/info_policies.html