PALEOENVIRONMENT RECONSTRUCTION IN THE EASTERN TETHYS DURING THE PALEOCENE-EOCENE THERMAL MAXIMUM USING TRACE METAL GEOCHEMISTRY

The Paleocene-Eocene Thermal Maximum is considered to be the warmest time interval of the Cenozoic Era, with average global temperatures over 10 degrees warmer than today’s, and are considered as ancient analogues for future climate change. Despite its tectonic significance, the paleoclimate history of the southeastern Tethys during the early Eocene remains poorly known since very few data are available. To reconstruct the paleoenvironment of the eastern Tethys (Kuzigongsu section) during the Paleocene-Eocene Thermal Maximum, inorganic geochemistry, including major, trace, and rare earth elements, is used to derive weathering, provenance, redox-sensitive and nutrient-sensitive proxies. These proxies include chemical index of alteration (CIA) as weathering proxy, enrichment factor of uranium (EFU) and barium (EFBa) as paleo-nutrient proxies, europium and cerium anomalies (Eu/Eu* and Ce/Ce*) as paleo-redox proxies. The inorganic geochemistry is obtained using an inductively coupled plasma - mass spectrometry (ICP-MS) for a total of 480 samples collected at the Kuzigongsu section in SW Tarim Basin, China. The samples spans the pre-onset excursion and the Paleocene-Eocene Thermal Maximum as supported by two prominent carbon isotope excursions (CIEs). Occurrences of ferromagnesian and clay minerals suggest that a warming-induced increased delivery of terrestrial input is registered in the sediments, consistent with the CIA data.