"The Ohio and Mt. Baldy Mining Districts near Marysvale, Utah occupy a cauldron complex in the Bullion Canyon Volcanics. This complex contains three rock groups of three volcanic episodes. The oldest is a volcanic cone framework series of lahars. The middle group is represented by lava flows, ash flows, and breccias which represent intra-caldera fill. The upper group consists of a local vent complex and the Delano Peak Tuff Member both of which may be related to ring fracture activity.
The stages of veining in the area include in order of gradational deposition: (1) early quartz veins, (2) pre-productive main stage quartz veins, (3) productive precious metal bearing main stage quartz veins, (4) productive base metal bearing main stage quartz veins, and (5) alunite veins. The initial fissures and veining probably accompanied resurgent doming of the Delano Peak Tuff Member and older rocks. A period of quiescence of about 7 m.y. occurred between Delano Peak Tuff Member deposition and base metal mineralization (Steven and others, 1977). Fissure deepening and vein mineralization was contemporaneous with magmatic doming. Trace amounts of Mo deposition increased with fissure deepening.
The earliest stage of hydrothermal alteration is that of alteration activity that formed K-silicate minerals. This preceded veining activity. Pervasive sericitization and argillization accompanied vein stage (1). Advanced argillic, sericitic, argillic, and propylitic alteration zones accompanied vein stages (2) through (5) and envelope those veins in a zonal fashion in the sequence listed.
The dome margins were intensely silicified sometime during vein stages (2) through (3). This fringe area developed stockwork fractures and open fissures after silicification. Vein solutions during vein stage (5) oxidized to sulphuric acid near the water table. K and Al, probably leached from the hot volcanic wall rock, reacted with the acid vein solutions to deposit alanite in the stockworks and fissures soon after base metal deposition"--Abstract, page ii.
Proctor, Paul Dean, 1918-1999
Grant, S. Kerry
Spokes, Ernest M., 1916-1995
Geosciences and Geological and Petroleum Engineering
M.S. in Geology
University of Missouri--Rolla
ix, 112 pages, 2 maps
Piute County (Utah)
© 1979 Lawrence M. Nuelle, All rights reserved.
Thesis - Restricted Access
Library of Congress Subject Headings
Geology -- Utah -- Piute County
Mines and mineral resources -- Utah -- Piute County
Print OCLC #
Electronic OCLC #
Link to Catalog RecordElectronic access to the full-text of this document is restricted to Missouri S&T users. Otherwise, request this publication directly from Missouri S&T Library or contact your local library. http://laurel.lso.missouri.edu/record=b1067843~S5
Nuelle, Laurence M., "Geology and mineralization, Ohio and Mt. Baldy Districts, Marysvale, Piute County, Utah" (1979). Masters Theses. 3198.