The late Maastrichtian warming event was defined by a global temperature increase of about 2.5-5°C, which occurred ~150-300 kyr before the K/Pg (Cretaceous/Paleogene) mass extinction. This transient warming event has traditionally been associated with a major pulse of Deccan Trap volcanism, however large uncertainties on radiogenic dating methods have long hampered a definitive correlation. Here we present a high-resolution, single-species benthic stable isotope record from the South Atlantic, calibrated to a new high resolution orbitally-tuned age model, to provide a revised chronology of the event, which we then correlate to the latest radiogenic dates of the main Deccan Trap eruption phases. The onset of deep-sea warming is synchronous with a 405-kyr eccentricity minimum, excluding a control by orbital forcing alone, although amplified carbon cycle sensitivity to orbital precession is evident during the greenhouse warming. Our data reveals that the initiation of deep-sea warming coincides, within uncertainty, with the onset of the main phase of Deccan volcanism, strongly suggesting a causal link.

Supplement to: Barnet, James S K; Littler, Kate; Kroon, Dick; Leng, Melanie J; Westerhold, Thomas; Röhl, Ursula; Zachos, James C (2017): A new high-resolution chronology for the late Maastrichtian warming event: Establishing robust temporal links with the onset of Deccan volcanism. Geology, 46(2), 147-150