Carbonate-platform changes response to the Paleocene-Eocene Thermal maximum

The Paleocene–Eocene Thermal Maximum (PETM, ~56 Ma) is a large negative carbon isotope excursion that testifies to a massive perturbation of the global carbon cycle and has been considered to be the best deep-time analogue for present and future climate change. However, most studies of the response of shallow-water carbonates to climate change during PETM have focused on individual sites and sections. To get a broader perspective we compiled published records of carbonate-platform environments across the Paleocene-Eocene transition in Tethys ocean. The shallow-marine benthic ecosystems during PETM were largely distinct in composition from those in the latest Paleocene or/and early Eocene. No obvious impact on biota and specifically on larger benthic foraminifera is observed at PETM onset, whereas the major biotic change occurs later on at PETM recovery, suggesting that biotic changes lag behind climate warming and carbon cycle perturbations in shallow-water ecosystem. We also inferred sedimentary responses at each site from direct or indirect indicators of sedimentological and relative sea-level change at the PETM. A transgressive trend that began at PETM onset, and continued through the CIE core, followed by a relative sea-level fall around the PETM recovery, implying the response of the relative sea-level to climate warming is characterized by a gradual rise, and a rapid fall. The demise of carbonate platform, increased terrestrial inputs and tropical storms has been widely observed in carbonate-platform environments across the PETM, suggesting enhanced erosion/chemical weathering and hydrological changes during the climate warming.