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GEOREF RECORD

High-potassium intrusive rocks of the Crandall ring-dike complex, Absaroka Mountains, Wyoming

A. M. Kudo and David E. Broxton
High-potassium intrusive rocks of the Crandall ring-dike complex, Absaroka Mountains, Wyoming
Geological Society of America Bulletin (April 1985) 96 (4): 522-528

Abstract

The Crandall ring-dyke complex has a gabbro-diorite core intruded by a shoshonitic ring-dyke, with medium-grained diorite as the most abundant rock. Both the core and the ring-dyke have been cut by granular and porphyritic quartz monzonite dykes. The shoshonite has large phenocrysts of plagioclase and augite in a microcrystalline groundmass of biotite, sanidine, plagioclase, amphibole, magnetite-ilmenite and glass. The plagioclase and pyroxene appear out of equilibrium with the surrounding matrix in both the ring dyke and core rocks. The gabbro, diorite and porphyritic quartz monzonite are characterized by plagioclase with bimodal core and rim compositions, indicating that one group is possibly xenocrystic. The gabbro can be formed as a cumulate from the diorite by fractional crystallization. The diorite, shoshonite, and even porphyritic quartz monzonite have chemical and textural signatures which strongly indicate contamination by plagioclase and pyroxene accumulation. The nature of non-contaminated magma is uncertain. Chemically, the diorite is a plutonic equivalent of shoshonite.


ISSN: 0016-7606
EISSN: 1943-2674
Coden: BUGMAF
Serial Title: Geological Society of America Bulletin
Serial Volume: 96
Serial Issue: 4
Title: High-potassium intrusive rocks of the Crandall ring-dike complex, Absaroka Mountains, Wyoming
Affiliation: Univ. N.M., Dep. Geol., Albuquerque, NM, United States
Pages: 522-528
Published: 198504
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 22
Accession Number: 1985-040539
Categories: Igneous and metamorphic petrologyGeochemistry of rocks, soils, and sediments
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 table, sketch map
N44°45'00" - N45°00'00", W110°00'00" - W109°30'00"
Secondary Affiliation: Los Alamos Natl. Lab., USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2018, American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
Update Code: 1985
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