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Evolution of a Quaternary peralkaline volcano: Mayor Island, New Zealand

Bruce F. Houghton·S.D. Weaver·C. J. N. Wilson·M. A. Lanphere
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Abstract

Mayor Island is a Holocene pantelleritic volcano showing a wide range of dispersive power and eruptive intensity despite a very limited range in magma composition of only 2% SiO2. The primary controls on this range appear to have been the magmatic gas content on eruption and a varying involvement of basaltic magma, rather than major-element chemistry of the rhyolites. The ca. 130 ka subaerial history of the volcano contains portions of three geochemical cycles with abrupt changes in trace-element chemistry following episodes of caldera collapse. The uniform major-element chemistry of the magma may relate to a fine balance between rates of eruption and supply and the higher density of the more evolved (Ferich) magmas which could be tapped only after caldera-forming events had removed significant volumes of less evolved but lighter magma. ?? 1992.

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Bruce F. Houghton, S.D. Weaver, C. J. N. Wilson, M. A. Lanphere. 1992. Evolution of a Quaternary peralkaline volcano: Mayor Island, New Zealand. https://pubs.usgs.gov/publication/70017171

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