Petrology and geochemistry of rocks from the Walvis Ridge: Deep Sea Drilling Project Leg 74, sites 525, 527 and 528.

Abstract

The variation in geochemistry between units and sites seems to be related to alteration or crystal fractionation as well as small-scale compositional variation in the mantle source of the basalts. The basalts of Leg 74 are similar to those dredged from the Walvis Ridge and the Rio Grande Rise. They show distinct compositional differences from basalts of the South Atlantic at this latitude and from basalts of Tristan da Cunha. If the Walvis Ridge basalts represent the product of a migrating hot-spot, then the mantle is heterogeneous in this area. (Following abstract)-K.A.R.