Petrographical and chemical study of basement basalts from the Galapagos spreading center, Leg 70.

Abstract

Petrographic, microprobe and XRF methods were used. In terms of alteration, the oldest basalts contain dark olive clay minerals, K-poor brown clay minerals and carbonates, whereas the young basalts contain yellowish-green K-clays and little or no carbonates.-K.A.R.