Mössbauer analyses were conducted on a sample of saponite selected from DSDP Leg 69 basalt core. The sample was initially placed within a nitrogen-purged container on-board Glomar Challenger approximately three hours after recovery, where it remained until analysis. The Mössbauer data revealed an original, in situ Fe2O3/FeO ratio of 0.46, with both Fe2+ and Fe3+ in octahedral coordination. With controlled exposure to air under ambient laboratory storage conditions, the proportion of Fe3+ increased from an original 30% to 51% over a period of about 11.5 months. The Fe3+ thus produced remained in octahedral coordination, and no observable changes occurred in the physical appearance of the sample.

Supplement to: Andrews, Anthony J; Dollase, W A; Fleet, M E (1983): A Mössbauer study of saponite in layer 2 basalt, Deep Sea Drilling Project Leg 69. In: Cann, JR; Langseth, MG; Honnorez, J; Von Herzen, RP; White, SM; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 69, 585-588