Elevated Post K-Pg Export Productivity in the Gulf of Mexico and Caribbean

This is a Preprint and has not been peer reviewed. This is version 1 of this Preprint.

Downloads

Download Preprint

Authors

Christopher Michael Lowery, Timothy J Bralower

Abstract

The global heterogeneity in export productivity after the Cretaceous-Paleogene (K-Pg) mass extinction is well documented, with some sites showing no change on geologic timescales, some demonstrating sustained decline, and a few showing a somewhat surprising increase. However, these records come from sites so widespread that a key outstanding question is the geographic scale of changes in export productivity, and whether similar environments (open ocean gyres, western boundary currents) responded similarly or whether heterogeneity is unrelated to environment. To address this, we developed three new Ba/Ti export productivity records from sites in the Gulf of Mexico and Caribbean which, combined with published data from a fourth site in the Chicxulub Crater itself, allows us to reconstruct regional changes in post K-Pg export productivity for the first time. We find that, on a regional scale, export productivity change is homogenous, with all four sites showing a ~300 kyr period of elevated export production just after the boundary, followed by a longer period of decline. Interestingly, this interval of elevated export production appears to coincide with the post K-Pg global micrite layer, which is thought to at least partially have been produced by blooms of carbonate-producing cyanobacteria and other picophytoplankton. We note from a global comparison of sites that elevated export productivity appears to be most common in tropical waters, which suggests that changing plankton ecology evidenced by the micrite layer altered the biological pump in a way that encouraged a temporary increase in export production in the tropics.

DOI

https://doi.org/10.31223/X59053

Subjects

Earth Sciences, Geochemistry, Paleobiology, Paleontology, Physical Sciences and Mathematics

Keywords

K-Pg, Paleoproductivity, DSDP, ODP, Gulf of Mexico, Caribbean, Cretaceous, paleogene, Ba/Ti, Mass extinction

Dates

Published: 2021-12-10 12:09

Last Updated: 2021-12-10 20:09

License

CC BY Attribution 4.0 International

Additional Metadata

Conflict of interest statement:
None

Data Availability (Reason not available):
https://www.ncei.noaa.gov/access/paleo-search/study/35081

Add a Comment

You must log in to post a comment.


Comments

There are no comments or no comments have been made public for this article.