Searching for an extinction event at the end of the Earth

English Abstract:

Disentangling the events surrounding the K-Pg extinction remains hotly debated with specific questions unanswered about the kill mechanism of both terrestrial and aquatic species, and the response of the marine environment to these events. Evidence has been presented that shows surface water foraminifera being severely impacted, however it is still unclear if global primary production was significantly affected. Novel isotopic techniques emerging are providing new insights to the geologic record, specifically Zn isotopes are showing promise as a proxy for paleo-productivity. Here we present new data from IODP core 577A, currently located approximately 2000 km east of Japan, spanning events before, during and after the K-Pg transition. Our novel approach first explores seawater eNd, and ^87/86Sr isotope ratios to observe any perturbations over this period. Preliminary eNd, results show a primitive signal, with an average value of -2.5, that may be a possible result of Deccan volcanism, which interestingly ^87/86Sr values display a delayed response. Exploring possible impacts on global productivity, d⁶⁶Zn values indicate that despite the dramatic events unfolding, seawater isotope ratios recorded in carbonates deposited on the other side of the Earth saw no significant changes in these isotope ratios.