"Careful petrographic study of the ash-flow tuffs in the Indian Peak District of southwestern Utah reveals hydrothermal alteration around the fluorite veins. The alteration minerals themselves and the intensity of alteration vary with distance from the veins. Primary plagioclase has altered to secondary feldspar, calcite, sericite, and traces of epidote and zoisite. Hornblende and biotite have altered to chlorite, calcite, and secondary iron oxide, and traces of epidote and zoisite. Diopside has changed to calcite and secondary iron oxide. An overall picture of the mining district shows that certain minerals increase and others decrease as one nears the veins. Hydrothermal quartz veins and veinlets increase in concentration toward the veins. Epidote and zoisite appear only in trace and small amounts and have no particular trend of concentration. Sericite generally increases toward the vein, but decreases immediately adjacent to it. Secondary feldspar varies very little until immediately near the veins, it decreases, as sericite does. Chlorite generally increases away from the vein. Secondary iron oxide occurs only in small amounts and seems to have no particular general trend. Calcite appears to increase away from the vein. Hydromuscovite appears only near the veins. The primary mineral content decreases toward the veins"--Abstract, page ii.
Grant, S. Kerry
Hagni, Richard D.
Day, D. E.
Geosciences and Geological and Petroleum Engineering
M.S. in Geology
V. H. McNutt Memorial Foundation
University of Missouri--Rolla
ix, 87 pages
© 1971 Michael Allan Tolley, All rights reserved.
Thesis - Open Access
Volcanic ash, tuff, etc. -- Utah
Hydrothermal alteration -- Utah
Fluorspar -- Analysis
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Electronic OCLC #
Link to Catalog Record
Tolley, Michael Allan, "Hydrothermal alteration of ash-flow tuffs in the Indian Peak District of southwestern Utah" (1971). Masters Theses. 7236.