9316419 Mehldahl As a young, actively rifting ocean basin, the Gulf of California represents an excellent opportunity to combine studies of modern marine sedimentary environments and faunas with studies of the Neogene rock record to understand better the evolution of rift basins and the fossil record that they accumulate. PI will provide models of lithofacies, biofacies and taphofacies for paleoenvironmental analysis of marine rift basins, with specific application to tectonic evolution of the Gulf of California. He will also investigate factors that control time-averaging and taphonomy in fossil assemblages. Collaboration is established with Mexican colleagues.