GEOLEX

Summary of Citation: Equity

Publication:
Emmons, W.H. and Larsen, E.S., 1923, Geology and ore deposits
   of the Creede district, Colorado: U.S. Geological Survey
   Bulletin, 718, 198 p.

Usage in Publication:
Equity quartz latite*

Modifications:	Geologic Province:	Dominant Lithology:
Named	San Juan Mountain province	Quartz latite

Summary:
Named as the upper formation of 5 of Alboroto group of Potosi volcanic series for development around the Equity mine in the Creede district, Mineral Co, CO in the San Juan Mountain province. Overlies Campbell Mountain rhyolite (named) of Alboroto, thereby occupying same general stratigraphic level as the Phoenix Park quartz latite (named) of Alboroto; these two latites are not in contact with each other. Upper contact covered. The quartz latite has abundant crystals of white plagioclase and some quartz, glassy orthoclase and biotite in a dense groundmass with delicate fluidal texture. Some olive-gray lenticular coarser areas present. Is present in upper part of West Willow Creek basin from upper Deerhorn Creek to and above Equity mine. Occurs in upper parts of stream valleys. Makes rugged outcrops. Geologic map. Is about 1,000 ft thick. Stratigraphic chart. Miocene age.

Summary of Citation: Equity

Publication:
Cross, C.W. and Larsen, E.S., 1935, A brief review of the geology
   of the San Juan region of southwestern Colorado: U.S. Geological
   Survey Bulletin, 843, 138 p., Also, U.S. Geological Survey
   Professional Paper 258.

Usage in Publication:
Equity quartz latite*

Modifications:	Geologic Province:	Dominant Lithology:
Areal limits	San Juan Mountain province

Summary:
Is a unit in the Creede district, Mineral Co, CO in the San Juan Mountain province. Is included in or mapped as part of the upper biotite-hornblende-quartz latite of the Alboroto quartz latite of the Miocene Potosi volcanic series. Geologic map.

Summary of Citation: Equity

Publication:
Steven, T.A. and Ratte, J.C., 1964, Revised Tertiary volcanic
   sequence in the central San Juan Mountains, Colorado; Article
   132, IN Geological Survey research 1963; short papers in
   geology and hydrology; Articles 122-170: U.S. Geological
   Survey Professional Paper, 475-D, p. D54-D63

Usage in Publication:
Equity Quartz Latite

Modifications:	Geologic Province:	Dominant Lithology:
Abandoned

Summary:
Abandoned as a unit in the Creede district, Ouray Co, CO in the San Juan Mountain province. Rocks formerly assigned to Equity are part of Nelson Mountain Formation as redefined in this report.

Summary of Citation: Equity

Publication:
Steven, T.A., Lipman, P.W. and Olson, J.C., 1974, Ash-flow
   stratigraphy and caldera structures in the San Juan volcanic
   field, southwestern Colorado, IN Cohee, G.V., and Wright,
   W.B., Changes in stratigraphic nomenclature by the U.S.
   Geological Survey, 1972: U.S. Geological Survey Bulletin,
   1394-A, p. A75-A82

Usage in Publication:
Equity Member*

Modifications:	Geologic Province:	Dominant Lithology:
Reinstated	San Juan Mountain province

Summary:
Reinstated as Equity Member of Rat Creek Tuff. Is younger than the outflow member of Rat Creek and older than the outflow member of Nelson Mountain Tuff. Is an Oligocene unit in the San Juan Mountain province.

Summary of Citation: Equity

Publication:
Steven, T.A. and Lipman, P.W., 1976, Calderas of the San Juan
   volcanic field, southwestern Colorado: U.S. Geological Survey
   Professional Paper, 958, 35 p.

Usage in Publication:
Equity Member*

Modifications:	Geologic Province:	Dominant Lithology:
Revised	San Juan Mountain province

Summary:
Original correlation of Nelson Mountain Tuff with Equity in the San Luis caldera thought to be correct. Is therefore removed from Rat Creek Tuff and reassigned to Nelson Mountain Tuff. Is used in the Creede district, Mineral Co, CO in the San Juan Mountain province. Of late Oligocene age.