Why are high-Mg# andesites widespread in the western Aleutians? A numerical model approach

Changyeol Lee, Scott D. King

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

High-Mg# andesites are thought to be derived from partial melting of subducting oceanic basalts. Slab thermal modeling has shown that this requires a young (<25 Ma), very shallow (flat) slab and/or high shear stresses along the slab surface. These conditions currently do not exist in the Aleutian arc, the typical locality of high-Mg# andesites. Using kinematic-dynamic thermal models of a subduction zone that include time-dependent age and subducting rate of the oceanic plate entering the trench since subduction initiation, we find that partial melting of the subducting oceanic basalts is restricted to the western Aleutians (from ~174° W to 195° W), consistent with the widespread occurrence of high-Mg# andesites in the western Aleutian arc. Our modeling suggests that consideration of temporal and spatial evolution of slab age and subducting rate along the Aleutian island arc is fundamental to the genesis of high-Mg# andesites in the western Aleutians.

Original languageEnglish
Pages (from-to)583-586
Number of pages4
JournalGeology
Volume38
Issue number7
DOIs
Publication statusPublished - 2010 Jul 1

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andesite
slab
partial melting
basalt
modeling
subduction zone
shear stress
island arc
trench
subduction
kinematics
rate

All Science Journal Classification (ASJC) codes

  • Geology

Cite this

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Why are high-Mg# andesites widespread in the western Aleutians? A numerical model approach. / Lee, Changyeol; King, Scott D.

In: Geology, Vol. 38, No. 7, 01.07.2010, p. 583-586.

Research output: Contribution to journalArticle

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AU - Lee, Changyeol

AU - King, Scott D.

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