The thin group of Tertiary sediments resting on essentially horizontal Senonian (Cretaceous) silty mudstones in the section exposed at Uloa consists of a basal nodular bed, an unconformably overlying coquinalike limestone, probably middle to upper Miocene in age, and a sequence of coarse- and fine-grained calcarenites, probably uppermost Miocene. Repeated reworking of the nodule bed with successive addition of younger material in a littoral environment is postulated. Deposition of the entire sequence took place in a shallow-water zone from Eocene to latest Miocene time, during which there were several episodes of transgression and regression.