 marine sediments paleoclimatology palynomorphs microfossils Paleocene-Eocene Thermal Maximum Paleogene oxygen Paleocene Tertiary Atlantic Coastal Plain United States climate change Cenozoic Eocene New Jersey O-18O-16 Foraminifera nannofossils Ocean Drilling Program Plantae Protista isotope ratios upper Paleocene Invertebrata lower Eocene stable isotopes Wilson Lake algae isotopes Leg 150X sediments 