Samples from Cenozoic and Mesozoic sediments drilled during ODP Leg 103 were analyzed for clay mineralogy. Kaolinite, chlorite, illite, and smectite occur in most of the samples studied; palygorskite and sepiolite occur principally in Paleogene and Eocene brown clays. In general, throughout the section deposited in the syn- and post-rift period, the more calcareous-rich pelagic sediments contain greater amounts of smectite and lesser amounts of kaolinite and chlorite than do the calcareous-poor terrigenous sediments. The clay data presented here also lend support to the general paleoenvironmental interpretation of a relatively warm climate throughout the Cretaceous and early Tertiary and a relatively cooler climate from the Oligocene to the present day.

Supplement to: Meyer, Audrey W; Davies, Thomas A (1988): Clay mineralogy of sediments from the Galicia margin, ODP Leg 103. In: Boillot, G; Winterer, EL; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 103, 461-475