STRUCTURE AND HYDROTHERMAL ALTERATION OF THE DIAMOND JOE STOCK, MOHAVE COUNTY, ARIZONA (FELDSPAR, QUARTZ, SERICITE).

Persistent Link:
http://hdl.handle.net/10150/187572
Title:
STRUCTURE AND HYDROTHERMAL ALTERATION OF THE DIAMOND JOE STOCK, MOHAVE COUNTY, ARIZONA (FELDSPAR, QUARTZ, SERICITE).
Author:
GERLA, PHILIP JOSEPH.
Issue Date:
1983
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The origin of fractures in plutons has been ascribed to differential stress resulting from regional tectonics, magmatic emplacement, crystallization, and cooling. The evolution of stress, and hence the evolution of fractures in plutons, controls the timing and spatial distribution of fluid flow and alteration. Quantitative data on fracture orientation, density, vein width, and alteration systematically obtained from the 70-m.y.-old Diamond Joe stock, west-central Arizona, were used to determine the evolution of stress and fractures within the stock during its crystallization. The dome-shaped chamber of the predominantly quartz monzonite stock is 8 km in diameter. Regional east-northeast compression produced the north-northwest crustal dilation necessary for the ascent and emplacement of the stock. Two-dimensional models using analytic solutions for stress in elastic media indicate that the prominent radial fractures within the stock developed in response to magma pressure, contraction, and regional stress. Most fractures formed by tensile failure during cooling, although magma pressure led to shear failure near the center. Deflection of radial fractures away from the east-northeast axis of the pluton at increasing distances from the center indicates north-northwest and east-northeast orientation of regional maximum and minimum principal stress, respectively, during crystallization. Apparently, north-northwest-trending uplift in the vicinity of the pluton led to a shallow local reversal of principal stress after magma emplacement. Theoretical strain estimates show a correlation with high fracture densities and abundant alteration along the north-northwest axis and the pluton margins. Zones of fracture selvage K-feldspar+quartz, muscovite+K-feldspar+quartz, and muscovite+chlorite+quartz alteration are concentric about the center of the stock and extend a short distance into the surrounding host rocks. Younger sericite+K-feldspar, argillic, and carbonate alteration occurs locally. Mineral equilibria and fluid inclusion data indicate low hydrothermal temperatures ( < 150°C) near the center of the stock and higher temperatures (200°C-400°C) near the margins. Apparently, fractures continued to open and fill as cooling proceeded within the center of the stock, whereas fluid circulation ceased at higher temperatures near the margins.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Geology -- Arizona -- Diamond Joe Peak.; Geology -- Arizona -- Mohave County.; Hydrothermal deposits -- Arizona -- Diamond Joe Peak.; Hydrothermal deposits -- Arizona -- Mohave County.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Geosciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Titley, S. R.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleSTRUCTURE AND HYDROTHERMAL ALTERATION OF THE DIAMOND JOE STOCK, MOHAVE COUNTY, ARIZONA (FELDSPAR, QUARTZ, SERICITE).en_US
dc.creatorGERLA, PHILIP JOSEPH.en_US
dc.contributor.authorGERLA, PHILIP JOSEPH.en_US
dc.date.issued1983en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe origin of fractures in plutons has been ascribed to differential stress resulting from regional tectonics, magmatic emplacement, crystallization, and cooling. The evolution of stress, and hence the evolution of fractures in plutons, controls the timing and spatial distribution of fluid flow and alteration. Quantitative data on fracture orientation, density, vein width, and alteration systematically obtained from the 70-m.y.-old Diamond Joe stock, west-central Arizona, were used to determine the evolution of stress and fractures within the stock during its crystallization. The dome-shaped chamber of the predominantly quartz monzonite stock is 8 km in diameter. Regional east-northeast compression produced the north-northwest crustal dilation necessary for the ascent and emplacement of the stock. Two-dimensional models using analytic solutions for stress in elastic media indicate that the prominent radial fractures within the stock developed in response to magma pressure, contraction, and regional stress. Most fractures formed by tensile failure during cooling, although magma pressure led to shear failure near the center. Deflection of radial fractures away from the east-northeast axis of the pluton at increasing distances from the center indicates north-northwest and east-northeast orientation of regional maximum and minimum principal stress, respectively, during crystallization. Apparently, north-northwest-trending uplift in the vicinity of the pluton led to a shallow local reversal of principal stress after magma emplacement. Theoretical strain estimates show a correlation with high fracture densities and abundant alteration along the north-northwest axis and the pluton margins. Zones of fracture selvage K-feldspar+quartz, muscovite+K-feldspar+quartz, and muscovite+chlorite+quartz alteration are concentric about the center of the stock and extend a short distance into the surrounding host rocks. Younger sericite+K-feldspar, argillic, and carbonate alteration occurs locally. Mineral equilibria and fluid inclusion data indicate low hydrothermal temperatures ( < 150°C) near the center of the stock and higher temperatures (200°C-400°C) near the margins. Apparently, fractures continued to open and fill as cooling proceeded within the center of the stock, whereas fluid circulation ceased at higher temperatures near the margins.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectGeology -- Arizona -- Diamond Joe Peak.en_US
dc.subjectGeology -- Arizona -- Mohave County.en_US
dc.subjectHydrothermal deposits -- Arizona -- Diamond Joe Peak.en_US
dc.subjectHydrothermal deposits -- Arizona -- Mohave County.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGeosciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorTitley, S. R.en_US
dc.contributor.committeememberNorton, D. L.en_US
dc.contributor.committeememberGuilbert, J. M.en_US
dc.contributor.committeememberMeijer, Arenden_US
dc.contributor.committeememberLoomis, T. P.en_US
dc.identifier.proquest8403229en_US
dc.identifier.oclc690260726en_US
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