Photomicrograph of Boulder Creek granite from east of junction of Middle Boulder and North Boulder Creek. Boulder County, Colorado. circa 1932.
Dates
Date Taken
1932
Summary
Album caption and index card: Photomicrograph of Boulder Creek granite from ridge half a mile east of junction of Middle Boulder and North Boulder Creeks. Primary gneissic structure indicated by quartz- oligoclase contact and by biotite is nearly horizontal in photograph. Slight secondary shearing shown by undulatory extinction of quartz in upper right. b, biotite; o, oligoclase; q, quartz. Polarized light. Boulder County, Colorado. Notes: Published as figure X-C in U.S.Geological Survey Professional paper 223. 1950.
Summary
Album caption and index card: Photomicrograph of Boulder Creek granite from ridge half a mile east of junction of Middle Boulder and North Boulder Creeks. Primary gneissic structure indicated by quartz- oligoclase contact and by biotite is nearly horizontal in photograph. Slight secondary shearing shown by undulatory extinction of quartz in upper right. b, biotite; o, oligoclase; q, quartz. Polarized light. Boulder County, Colorado.
Notes: Published as figure X-C 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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