The controls on phosphorize formation and mineralization rates will be determined by analysis of the upper several meters of the shelf sediments from cores sampled during ODP leg 112 and several wide-diameter cores to be sampled during two future expeditions. Detailed chronostratigraphic analysis will be obtained by stable isotope analysis of benthonic foraminifera, bulk sediment dating and absolute dating interdispersed authigenic minerals and shell material. These data will allow the PIs to relate the formation and occurrence of phosphorize to environmental parameters over a time scale of hundreds to tens of thousands of years.