Pulses of Middle Eocene to Earliest Oligocene Climatic Deterioration in Southern California and the Gulf Coast

A general deterioration of terrestrial climate took place during middle Eocene to earliest Oligocene time in southern California, based on evidence of sedimentary features, vertebrate fossils, and fossil pollen, and in the Gulf Coast, based on evidence of plant megafossils and fossil pollen. Pollen data, calibrated by calcareous nannofossil ages, indicate four events of rapid floral and/or vegetational change among angiosperms during this time interval