Evolution of a Maastrichtian–Paleocene tropical shallow-water carbonate platform (Qalhat, NE Oman)

The biostratigraphy (larger foraminifers, dasycladaleans), microfacies, sedimentology, and geochemistry (δ 13C, strontium-isotope stratigraphy) of a continuous, 148-m-thick section of shallow-water platform carbonates that contain the Cretaceous/Paleogene (K/P) boundary were analyzed. The boundary is constrained within a 7-m-thick interval, between the last occurrence of Maastrichtian larger benthic foraminifers and the first occurrence of Danian benthic foraminifers. Although this interval is intensively dolomitized, there is no sedimentological evidence of a major hiatus at the K/P boundary. The correlation of bulk rock δ 13C values with stable isotope data from DSDP Site 384 (NW Atlantic Ocean) supports this interpretation and indicates a Selandian age for the top of the section. The Qalhat section is a unique example of a carbonate platform that has recorded persisting open marine environmental conditions across the K/P boundary (Maastrichtian–Selandian), as indicated by the abundance of rudists, larger benthic foraminifers (Maastrichtian), calcareous algae and scleractinian corals.