Dike Ridge from Porphyry Basin, shows characteristic cliffs of San Juan tuff. Hinsdale County, Colorado. 1904.
Dates
Date Taken
1904-08-04
Summary
Dike Ridge from Porphyry Basin, shows characteristic cliffs of San Juan tuff- agglomerate and overlying Potosi volcanic series, with four notable dikes of monzonite porphyry, which in some places stand out as walls. Hinsdale County, Colorado. August 4, 1904. Figure 8 in U.S. Geological Survey. Folio 153. 1907.
Summary
Dike Ridge from Porphyry Basin, shows characteristic cliffs of San Juan tuff- agglomerate and overlying Potosi volcanic series, with four notable dikes of monzonite porphyry, which in some places stand out as walls. Hinsdale County, Colorado. August 4, 1904. Figure 8 in U.S. Geological Survey. Folio 153. 1907.
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