Photomicrograph of porphyritic hornblende diorite taken from Swan River. Boulder County, Colorado. circa 1932.
Dates
Date Taken
1932
Summary
Album caption and index card: Photomicrograph of porphyritic hornblende diorite of group 4 from Swan River 2 miles south of Tiger [extinct mining town], showing reaction series. Core of augite (a) bordered by hornblende (h) which in turn is completely rimmed by biotite (b). Cross nicols. Boulder County, Colorado. Notes: Published as figure X-F in U.S.Geological Survey. Professional Paper 223. 1950.
Summary
Album caption and index card: Photomicrograph of porphyritic hornblende diorite of group 4 from Swan River 2 miles south of Tiger [extinct mining town], showing reaction series. Core of augite (a) bordered by hornblende (h) which in turn is completely rimmed by biotite (b). Cross nicols. Boulder County, Colorado.
Notes: Published as figure X-F in U.S.Geological Survey. Professional Paper 223. 1950.
Available in the U.S. Geological Survey Denver Library Photographic Collection, Lovering, T.S.
Rights
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