engleski

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

We show crucial evidence for the Cretaceous–Paleogene (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, that 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 2 cm thick reddish-brown clayey mudstone containing planktonic foraminifera typical for 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 the “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.

Cretaceous–Paleogene, Tethys, Adriatic carbonate platform, asteroid impact, tsunami

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