Petrological investigations of oceanic rocks carried out during the past several years have shed considerable light on the geochemistry of basalts from various structural provinces in the ocean basins. It is evident from these studies that variations in chemistry exist between volcanics in different provinces and even within individual provinces.

Supplement to: Zolotarev, Boris P; Margolin, Len (1983): Geochemistry and rare-earth element abundances of basalts from Sites 482, 483, and 485 in the Gulf of California. In: Lewis, BTR; Robinson, P; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 65, 579-590