Abstract

Basalt microlapilli consisting of glassy particles and rock fragments were recovered in lower Miocene pelagic sediment from Deep Sea Drilling Project site 32 in the northeastern Pacific Ocean. Major-element chemistry indicates that the parent tholeiitic magma was high in iron and titanium, similar to many of the abyssal basalts from the eastern Pacific Ocean, and the relatively high K2O content suggests additional fractionation before eruption. The microlapilli most likely were erupted subaerially from an island volcano, although a shallow submarine source cannot be discounted. If wind were the only method of dispersal, then the volcano was probably within 100 km of site 32. If surface or density currents played a role in transport, however, the volcano may have been at a greater distance.

First Page Preview

First page PDF preview
You do not currently have access to this article.