Skip to Main Content
Book Chapter

Aleutian magmas in space and time

By
Suzanne Mahlburg Kay
Suzanne Mahlburg Kay
Institute for the Study of the Continents (INSTOC), Snee Hall, Cornell University, Ithaca, New York 14853
Search for other works by this author on:
Robert W. Kay
Robert W. Kay
Department of Geological Sciences and Institute for the Study of the Continents (INSTOC), Snee Hall, Cornell University, Ithaca, New York 14853
Search for other works by this author on:
Published:
January 01, 1994

Abstract

The Aleutian arc provided the setting for a proposal by Coats (1962) that arc magmas are related to a subducted oceanic plate in a convergent tectonic setting—a proposal that predated the theory of plate tectonics. Since that time, the study of Aleutian arc magmas has generated controversies over their origin and evolution that are fundamental to understanding the origin of magmas in all island arcs.

The first and longest controversy has been over the composition of the most important parental lava (precursor to most arc magmas) derived from the mantle. The question is whether this magma is a high-Al basalt generated by partial melting of the subducting plate (e.g., Marsh, 1982) or a more Mg-rich basalt derived from the peridotite overlying the plate that has been fluxed by a component from the plate (Kay, 1977; Perfit and others, 1980b).

The second major controversy is over the origin of the arctype trace-element and isotopic characteristics of Aleutian magmas. The models considered for the magmatic source include (1) a mixture of subducted oceanic crustal and sedimentary components with a depleted mid-oceanic ridge-type mantle (Kay and others, 1978; Kay, 1980); (2) a subducted oceanic crustal source (Marsh, 1976) that includes a subducted sedimentary component (Brophy and Marsh, 1986); and (3) an upper mantle source composed of mid-oceanic ridge and oceanic island-type components (Morris and Hart, 1983). The third major controversy is over the origin of the petrologic and geochemical diversity along the arc and within individual centers, and the relation of this diversity

You do not currently have access to this article.

Figures & Tables

Contents

DNAG, Geology of North America

The Geology of Alaska

George Plafker
George Plafker
U.S. Geological Survey MS 904, 345 Middlefield Road Menlo Park, California 94025
Search for other works by this author on:
Henry C. Berg
Henry C. Berg
115 Malvern Avenue Fullerton, California 92632
Search for other works by this author on:
Geological Society of America
Volume
G-1
ISBN electronic:
9780813754536
Publication date:
January 01, 1994

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal