DMCA
A detailed geochemical study of the island arc crust: the Talkeetna arc section, south-central (2006)
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BibTeX
@MISC{Greene06adetailed,
author = {Andrew R. Greene and Susan M. Debari and Peter B. Kelemen and Jurek Blusztajn and Peter and D. Clift},
title = {A detailed geochemical study of the island arc crust: the Talkeetna arc section, south-central},
year = {2006}
}
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Abstract
Chugach Mountains of south–central Alaska is 5–18 km wide and extends for over 150 km. This accreted island arc includes exposures of upper mantle to volcanic upper crust. The section comprises six lithological units, in order of decreasing depth: (1) residual upper mantle harzburgite (with lesser proportions of dunite); (2) pyroxenite; (3) basal gabbronorite; (4) lower crustal gabbronorite; (5) mid-crustal plutonic rocks; (6) volcanic rocks. The pyroxenites overlie residual mantle peridotite, with some interfingering of the two along the contact. The basal gabbronorite overlies pyroxenite, again with some interfingering of the two units along their contact. Lower crustal gabbronorite (10 km thick) includes abundant rocks with well-developed modal layering. The mid-crustal plutonic rocks include a heterogeneous assemblage of gabbroic rocks, dioritic to tonalitic rocks (30–40 % area), and concentrations of mafic dikes and chilled mafic inclusions. The volcanic rocks (7 km thick) range from
Keyphrases
detailed geochemical study talkeetna arc section island arc crust mid-crustal plutonic rock volcanic rock crustal gabbronorite km thick basal gabbronorite upper mantle lithological unit volcanic upper crust chugach mountain mafic inclusion heterogeneous assemblage residual mantle peridotite south central alaska gabbroic rock mafic dike tonalitic rock basal gabbronorite overlies accreted island arc well-developed modal layering abundant rock residual upper mantle harzburgite
