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Post-accretion magmatism within the Kuiu-Etolin igneous belt, Southeastern Alaska

Jennifer Lindline, William A. Crawford, Maria Luisa Crawford and Gomaa I. Omar
Post-accretion magmatism within the Kuiu-Etolin igneous belt, Southeastern Alaska
The Canadian Mineralogist (August 2000) 38, Part 4: 951-974


The 20 m.y. Burnett Inlet bimodal igneous complex in central SE Alaska consists of coeval granite and gabbro plutons. The within-plate characteristics of these rocks relate to the post-terrain accretionary magmatism within the Kuiu-Etolin igneous belt to the extensional tectonic regime described from the neighbouring Queen Charlotte Basin. It is suggested that tholeiitic mafic magma was generated by partial melting of enriched upper mantle via decompression-induced mantle melting in a tensional environment. Mafic magma ponded at the base of the crust causing partial melting of a source comprised of greywacke and intercalated volcanogenic material to generate mildly peraluminous A-type granite. Mafic and felsic magmatism began to evolve at depth by fractional crystallization, and rose through the lower and middle crust along post-Eocene extension-related fractures. These magmas underwent further fractional crystallization after their emplacement in the upper crust. Intrusion of mafic magma into the felsic magma chamber caused superheating and convection of the granitic melt, enabling the entire magma suite to enter an eruptive phase, leading to rapid crystallization and cooling of the magma system.

ISSN: 0008-4476
EISSN: 1499-1276
Coden: CAMIA6
Serial Title: The Canadian Mineralogist
Serial Volume: 38, Part 4
Title: Post-accretion magmatism within the Kuiu-Etolin igneous belt, Southeastern Alaska
Affiliation: New Mexico Highlands University, Natural Resources Management Program, Las Vegas, NM, United States
Pages: 951-974
Published: 200008
Text Language: English
Summary Language: French
Publisher: Mineralogical Association of Canada, Ottawa, ON, Canada
References: 79
Accession Number: 2001-009688
Categories: Geochemistry of rocks, soils, and sedimentsIgneous and metamorphic petrology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 2 tables, geol. sketch maps
N56°00'00" - N56°19'60", W132°34'60" - W132°04'60"
Secondary Affiliation: Bryn Mawr College, USA, United StatesUniversity of Pennsylvania, USA, United States
Country of Publication: Canada
Secondary Affiliation: GeoRef, Copyright 2018, American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
Update Code: 200104
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