Geochemistry at DSDP Holes 82-561, 82-562 and 82-564

Analyses of samples from Chemical Group II, Hole 561; Chemical Group I, Hole 562; and two pillows and a flow from Hole 564 show that the chemical groups and the individual structures are compositionally homogeneous for the data presented here except for the alkalies, Na2O and Cs, and transition metals, FeO and Co, and sometimes Sc and Cr. The scatter in the alkalies is attributed to alteration and the scatter in the transition metals is attributed to a short-range segregation model.

Although the pillows and flow from Hole 564 are each compositionally homogeneous, their compositions are distinct from one another. These results cannot support the preliminary interpretation by shipboard scientists that the basalts from Hole 564 comprise a single chemical group.