GSA Annual Meeting in Seattle, Washington, USA - 2017

Paper No. 153-54
Presentation Time: 9:00 AM-6:30 PM

EVIDENCE OF LATE PALEOCENE-EARLY EOCENE POSSIBLE OCEAN ACIDIFICATION RECORDED IN THE ADRIATIC CARBONATE PLATFORM


OEFINGER, Jordan, Jackson School of Geosciences, University of Texas at Austin, 23 San Jacinto Blvd & E 23rd St, Austin, TX 78712, WEISS, Anna M., Jackson School of Geosciences, The University of Texas at Austin, 2305 Speedway, Stop C1160, Austin, TX 78713, KOŠIR, Adrijan, Research Center of the Slovenian Academy of Arts and Sciences, Ivan Rakovec Institute of Palaeontology, Novi trg 2,, Ljubljana, SI-1000, Slovenia and MARTINDALE, Rowan C., Jackson School of Geosciences, University of Texas at Austin, 1 University Station C1100, Austin, TX 78712, jordanoefinger@utexas.edu

The Paleocene-Eocene Thermal Maximum (PETM), a period of abrupt global warming events, is linked to a rapid release of large amounts of carbon into the Earth system. This sudden influx is hypothesized to have caused a mass acidification of surface ocean waters and a decrease in carbonate deposition in shallow water ramps and carbonate platforms. While rapid ocean acidification has the potential to devastate marine ecosystems, evidence of abrupt changes in pH and saturation have only been reported from deep-sea records. A well-preserved shallow carbonate platform from the Kras region of Slovenia records, continuous exposures of long term deposition, including the Paleocene-Eocene boundary, which manifests as a dissolution horizon. Through the analysis of dissolution surfaces found in this region, shallow platform ocean acidification is considered as a possible cause for the horizons. We analyze boundary samples to determine if the surfaces formed in an acidified ocean, subaerially, or are due to erosion diagenesis (i.e. stylolitic) using petrography and elemental mapping of the boundary. These surfaces have been analyzed using the Environmental Scanning Electron Microscope (ESEM) Energy Dispersive Spectra (EDS) to create a preliminary elemental map of the focus area. Then, samples will be mapped on the Electron Microprobe (EPMA) to gather more detailed data on the boundary composition to further explain the preserved surface of the PETM. The analyses of these dissolution surfaces in the Kras region will be used to determine whether ocean acidification occurred in this region during the PETM.