Paleoclimate reconstruction of the Paleocene-Eocene Thermal Maximum using carbon isotopes of black carbon and pollen
Presentation Type
Poster
Faculty Advisor
Ying Cui
Access Type
Event
Start Date
26-4-2023 11:00 AM
End Date
26-4-2023 12:00 PM
Description
The Paleocene-Eocene Thermal Maximum (PETM, ca. 56 million years ago or Ma) was a rapid global warming period characterized by significant carbon cycle perturbations and increasing global temperatures. Wildfires were common during the PETM, which likely contributed to high concentrations of atmospheric carbon dioxide (pCO2). One byproduct of these wildfires is black carbon (BC), or carbonaceous product of incomplete combustion of biomass or peatlands. δ13CBC values decrease from -23 to -24‰ from the Kuzigongsu section in the Tarim Basin of the eastern Tethys Ocean, indicating gymnosperm-dominated vegetation prior to the PETM, and a transition to angiosperm-dominated vegetation during the PETM (De Palma et al., in prep). The observed pattern of δ13CBC during the PETM suggests that the main source of the BC found in our samples may have been the combustion of living biomass, but δ13C of pollen samples can help test this hypothesis. To better understand how the vegetation was affected during the PETM, pollen samples will also be extracted and analyzed for their stable carbon isotopes. The use of pollen and its isotopes (δ13Cpollen) is more practical in reconstructing the paleoenvironment of the PETM since they can further determine how vegetation and regional precipitation responded to the changing climate. The δ13Cpollen work is still ongoing, but preliminary data on δ13CBC support that the extent of climate change that occurred throughout the PETM can then be compared to the factors driving the contemporary climate crisis.
Paleoclimate reconstruction of the Paleocene-Eocene Thermal Maximum using carbon isotopes of black carbon and pollen
The Paleocene-Eocene Thermal Maximum (PETM, ca. 56 million years ago or Ma) was a rapid global warming period characterized by significant carbon cycle perturbations and increasing global temperatures. Wildfires were common during the PETM, which likely contributed to high concentrations of atmospheric carbon dioxide (pCO2). One byproduct of these wildfires is black carbon (BC), or carbonaceous product of incomplete combustion of biomass or peatlands. δ13CBC values decrease from -23 to -24‰ from the Kuzigongsu section in the Tarim Basin of the eastern Tethys Ocean, indicating gymnosperm-dominated vegetation prior to the PETM, and a transition to angiosperm-dominated vegetation during the PETM (De Palma et al., in prep). The observed pattern of δ13CBC during the PETM suggests that the main source of the BC found in our samples may have been the combustion of living biomass, but δ13C of pollen samples can help test this hypothesis. To better understand how the vegetation was affected during the PETM, pollen samples will also be extracted and analyzed for their stable carbon isotopes. The use of pollen and its isotopes (δ13Cpollen) is more practical in reconstructing the paleoenvironment of the PETM since they can further determine how vegetation and regional precipitation responded to the changing climate. The δ13Cpollen work is still ongoing, but preliminary data on δ13CBC support that the extent of climate change that occurred throughout the PETM can then be compared to the factors driving the contemporary climate crisis.