Trace element analyses, Sr and Nd isotopic data of shark teeth and sediments from La Meseta Formation, Seymour Island, Antarctica

The purpose of this study is to test the timing of Drake Passage opening using rare earth element (REE) concentrations, strontium, and neodymium isotope analyses on fossil shark teeth and neodymium isotopes on sediments from the Eocene La Meseta Formation , located on Seymour Island, in the Antarctic Peninsula, East Antarctica. The shark teeth εNd vary from -7 to -4, between present day Pacific and Atlantic seawater εNd values, and higher than associated sediments (εNd = -9 to -6), while 87Sr/86Sr show a narrow range 0.707722 to 0.707775, corresponding to Eocene seawater. The PAAS-normalized REE patterns show enrichment in the middle ones with respect to both light and heavy ones and no cerium anomalies. The data is used to infer the presence of Pacific seawater in the Atlantic sector of the Southern Ocean earlier than 41 My.