Discovery and interpretation of mafic ignimbrites at Tanna, Vanuatu, SW Pacific

Abstract:

Two voluminous ignimbrite sequences were emitted during the Pleistocene development of the Tanna volcanic complex. The composition of the juvenile clasts from the older ignimbrites is unsually mafic (SiO2:53 to 58%) with glasses ranging in composition from basaltic andesite to dacite-rhyolite. The respective roles of magma mixing and fractional crystallization are discussed in order to explain these variations. The ignimbrites represent massive and simultaneous outbursts of cogenotic magmas, whose glassy phases range in SiO2 contents from 55-56, 61-62 to 69%. There is an abridged English version. -from English summary

Año de publicación:

1992

Keywords:

Fuente:

scopus