ARCUS | Arctic Research Consortium of the United States

7th Annual ARCUS Award for Arctic Research Excellence

Submitted by		Pavel Izbekov
Authors		Pavel Izbekov, J. C. Eichelberger, L. C. Patino, T. A. Vogel, and B. V. Ivanov
Category		Physical Science
Title		Calcic Cores of Plagioclase Phenocrysts in Andesite from Karymsky Volcano: Evidence for Rapid Introduction by Basaltic Replenishment
Affiliation		Geophysical Institute/ Department of Geology & Geophysics, UAF, College of Science, Engineering and Mathematics, Fairbanks, AK, USA

Abstract

Calcic cores in plagioclase of Karymsky andesite of the 1996–2000 cycle texturally and compositionally (both trace- and major-elements) mimic the plagioclase phenocrysts of basalt erupted 6 km away at the onset of the cycle. These observations support the view that simultaneous eruption of andesite and basalt at Karymsky in the beginning of the cycle represents an example of replenishment and eruption triggering of an andesitic reservoir. Homogeneity of andesitic output occurred within two months. This suggests to us that blending of injected basalt into reservoir magma was thorough and rapid.