The Paleocene–Eocene thermal maximum (PETM) in Svalbard — clay mineral and geochemical signals

For the first time the Paleocene–Eocene Thermal Maximum (PETM) interval has been identified in drillcores and field outcrops from the Paleogene Central Basin in Svalbard, based on mineralogical and geochemical information. Grumantbyen and Frysjaodden formations, a more than 300 m thick Paleogene interval, representing deltaic, delta-influenced marine shelf and deep water slope environments. The PETM has been recognized in the deepest and most distal deposits in the lower parts of the Frysjaodden Formation. Here, this global event is displayed in clay mineralogical distributions as significantly increased kaolinite abundances reflecting a period with intensified chemical weathering in the land areas surrounding this Paleogene basin. The period was characterized by dominantly reducing sea floor conditions, as seen in the Th/U distribution and the well developed parallel lamination in the pyrite-rich shales; all to be expected during an interval with increased temperature and precipitation.