Post-impact event bed (tsunamite) at the Cretaceous-Palaeogene boundary deposited on a distal carbonate platform interior

• Published in: Terra Nova
• Main Authors: Korbar, Tvrtko, McDonald, Iain, Premec Fucek, Vlasta, Fucek, Ladislav, Posilovic, Hrvoje
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2017
• Subjects: QE Geology; Planktonic foraminifera
• Online Access: https://orca.cardiff.ac.uk/id/eprint/98381/; https://doi.org/10.1111/ter.12257; https://orca.cardiff.ac.uk/id/eprint/98381/1/2017_Korbar_et_al_TerraNova_ACCEPTED.pdf

We show crucial evidence for the Cretaceous–Palaeogene (K–Pg) boundary event recorded within a rare succession deposited in an inner-platform lagoon on top of a Mesozoic, tropical, intra-oceanic (western Tethys) Adriatic carbonate platform, which is exposed at Likva cove on the island of Brač (Croatia). The last terminal Maastrichtian fossils appear within a distinct 10–12 cm thick event bed that is characterized by soft-sediment bioturbation and rare shocked-quartz grains, and is interpreted as a distal tsunamite. Directly overlying this is a 2 cm thick reddish-brown clayey mudstone containing planktonic foraminifera typical of the basal Danian, and with elevated platinum-group elements in chondritic proportions indicating a clear link to the Chicxulub asteroid impact. These results strongly support the first discovery of a “potential” K–Pg boundary tsunamite on the neighboring island of Hvar, and these two complementary sections represent probably the most complete record of the event among known distal shallow-marine successions.