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Petrology and tectonic significance of augen gneiss from a belt of Mississippian granitoids in the Yukon-Tanana terrane, east-central Alaska

Cynthia Dusel-Bacon and John N. Aleinikoff
Petrology and tectonic significance of augen gneiss from a belt of Mississippian granitoids in the Yukon-Tanana terrane, east-central Alaska
Geological Society of America Bulletin (April 1985) 96 (4): 411-425

Abstract

An approximately E-W-trending belt of porphyritic peraluminous granitic rocks, metamorphosed and deformed to augen gneiss, is exposed for 400 km across the Yukon-Tanana terrain. Chemical, textural, and isotopic data from large augen-gneiss bodies indicate that these bodies originated as early Mississippian granitic rocks that assimilated, or were anatectically derived from, early Proterozoic crust or metasedimentary rocks. This plutonic belt probably formed in a middle Palaeozoic continental magmatic arc that developed near the edge of a Precambrian craton somewhere along the western margin of North America and was later translated NW to its present location. U/Pb zircon data and concordance of augen-gneiss contacts with metamorphic layering and with probable late-stage sills suggest that regional metamorphism to amphibolite facies of these rocks was synchronous (late kinematic) with intrusion of the porphyritic granitic protolith.


ISSN: 0016-7606
EISSN: 1943-2674
Coden: BUGMAF
Serial Title: Geological Society of America Bulletin
Serial Volume: 96
Serial Issue: 4
Title: Petrology and tectonic significance of augen gneiss from a belt of Mississippian granitoids in the Yukon-Tanana terrane, east-central Alaska
Affiliation: U. S. Geol. Surv., Menlo Park, CA, United States
Pages: 411-425
Published: 198504
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 78
Accession Number: 1985-040530
Categories: Igneous and metamorphic petrologyGeochemistry of rocks, soils, and sediments
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 2 tables, geol. sketch map
N63°00'00" - N65°00'00", W147°00'00" - W141°00'00"
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
Program Name: USGSOPNon-USGS publications with USGS authors
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