AR-40/AR-39 AGES AND STRATIGRAPHY OF THE LATERA CALDERA, ITALY

被引：37

作者：

TURBEVILLE, BN

机构：

[1] Department of Geological Sciences, The University of Texas at Austin, Austin, 78713-7909, Texas

来源：

BULLETIN OF VOLCANOLOGY | 1992年 / 55卷 / 1-2期

关键词：

D O I：

10.1007/BF00301124

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

The Latera caldera is a well-exposed volcano where more than 8 km3 of mafic silica-undersaturated potassic lavas, scoria and felsic ignimbrites were emplaced between 380 and 150 ka. Isotopic ages obtained by Ar-40/Ar-39 analysis of single sanidine crystals indicate at least four periods of explosive eruptions from the caldera. The initial period of caldera eruptions began at 232 ka with emplacement of trachytic pumice fallout and ignimbrite. They were closely followed by eruption of evolved phonolitic magma. After roughly 25 ky, several phonolitic ignimbrites were deposited, and they were followed by phreatomagmatic eruptions that produced trachytic ignimbrites and several smaller ash-flow units at 191 ka. Compositionally zoned magma then erupted from the northern caldera rim to produce widespread phonolitic tuffs, tephriphonolitic spatter, and scoria-bearing ignimbrites. After 40 ky of mafic surge deposit and scoria cone development around the caldera rim, a compositionally zoned pumice sequence was emplaced around a vent immediately northwest of the Latera caldera. This activity marks the end of large-scale explosive eruptions from the Latera volcano at 156 ka.

引用

页码：110 / 118

页数：9

共 22 条

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