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 Fućek, Vlasta, Fuček, Ladislav, Posilović, Hrvoje
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2017
• Subjects: Geology; Planktonic foraminifera
• Online Access: http://dx.doi.org/10.1111/ter.12257; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fter.12257; https://onlinelibrary.wiley.com/doi/pdf/10.1111/ter.12257

Abstract 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 characterised 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 neighbouring island of Hvar, and these two complementary sections represent probably the most complete record of the event among known distal shallow‐marine successions.