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U.S. Department of Energy
Office of Scientific and Technical Information

Intrusive rocks northeast of Steamboat Springs, Park Range, Colorado

Technical Report ·
OSTI ID:6094037
Major Precambrian and minor Tertiary intrusive rocks northeast of Steamboat Springs in the Park Range between 40/sup 0/30' and 40/sup 0/45' N. lat. are described and compared with related rocks elsewhere in Colorado and Wyoming. The Precambrian intrusives were emplaced in a sequence of high-grade interlayered felsic gneisses, amphibolites, and pelitic schists of sedimentary and volcanic origin. These rocks are cut by a major northeast-trending Precambrian shear zone where mainly left lateral movement of 1/2 to 1 mile is certain. Cumulative movement of many miles is possible. The Precambrian intrusives consist of a batholith, the Mount Ethel pluton, a smaller Buffalo Pass pluton, and small dikes or lenses of fine-grained porphyry, pegmatites, and ultramafics.
Research Organization:
Geological Survey, Denver, CO (USA)
OSTI ID:
6094037
Report Number(s):
USGS-PP-1041; ON: DE83902180
Country of Publication:
United States
Language:
English