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A-type granites revisited; assessment of a residual-source model

Robert A. Creaser, Richard C. Price and Richard J. Wormald
A-type granites revisited; assessment of a residual-source model
Geology (Boulder) (February 1991) 19 (2): 163-166


A residual-source model for the origin of A-type granites is assessed by examining the likely mineral content and geochemistry of the residue remaining from generation of an I-type granite. Although this model may explain some characteristics of A-type granites, available data suggest that a residual source is unlikely to generate a partial melt with the appropriate major element characteristics. An alternative model for the origin of some A-type granites involves partial melting of crustal igneous rocks of tonalitic to granodioritic composition. Modeling the partial melting of these source rocks suggests that partial melts with water contents appropriate for A-type granites may be generated by approximately 15% to 40% melting. This model can predict many other characteristics of A-type granites.

ISSN: 0091-7613
EISSN: 1943-2682
Serial Title: Geology (Boulder)
Serial Volume: 19
Serial Issue: 2
Title: A-type granites revisited; assessment of a residual-source model
Affiliation: La Trobe Univ., Dep. Geol., Bundoora, Victoria, Australia
Pages: 163-166
Published: 199102
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 24
Accession Number: 1991-011342
Categories: Igneous and metamorphic petrology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 table
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute.
Update Code: 1991
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