stripes
Occurrence number:
174-00-073
Country:
United States
Region:
Wyoming
Location:
Longitude: -104.35, Latitude: 44.2
Carbonatite:
No
Inyan Kara Mountain stands 100 m or more above the surrounding countryside and forms bold, near vertical cliffs. The principal rock type is a syenite with prominent oligoclase and some orthoclase phenocrysts, in a trachytic groundmass of alkali feldspar, diopside/aegirine-augite, minor brown amphibole and magnetite. A highly feldspathic facies with a little quartz occurs near the margins in some places.
References:
MAPEL, W.J. and PILLMORE, C.L. 1963. Geology of the Inyan Kara Mountain Quadrangle, Crook and Weston Counties, Wyoming. Bulletin, United States Geological Survey, 1121-M: 1-56.
DARTON, N.H. 1905. Sundance Folio: Wyoming-South Dakota. Geologic Atlas of the United States: 127
Location: