THE RESILIENCE OF A NORTHERN TETHYAN CARBONATE PLATFORM DURING THE OAE1A: GEOCHEMICAL INSIGHTS FROM THE CORBIÈRES REGION OF FRANCE
We use mineralogical and geochemical data along with petrographic analysis of samples from France assess impacts of detrital input, redox conditions, paleoproductivity and nutrient supply on efficiency of the carbonate factory of this platform in the Corbières. Geochemical data provide proxies for paleoproductivity (Sixs, Sr/Al, P/Al, P2O5xs), detrital input (%terrigenous, Ti/Al, Zr/Al, Zr/Zrsh), and redox conditions (Mn*, Mn/Al, Mnxs).
Results show P2O5xs and %terrigenous curves vary with lithology through the section, and within the limestone sections both proxies vary little and remain low. But, in the marls both P2O5xs and %terrigenous increase, specifically %terrigenous values range from 10 - 85%. Increased nutrient and terrigenous inputs were detrimental to rudist-dominated ecosystems that were replaced by biotic association with suspension feeders. Our results provide information about the resilience of the carbonate platforms to changes during the Early Aptian OAE1a and increase knowledge about how chemical elements act during diagenesis, thus enhancing our ability to identify the most reliable geochemical proxies.