Evidence for shelf acidification during the onset of the Paleocene‐Eocene Thermal Maximum

A transect of paleoshelf cores from Maryland and New Jersey contains an ~0.19 m to 1.61 m thick interval with reduced percentages of carbonate during the onset of the Paleocene‐Eocene Thermal Maximum (PETM). Outer paleoshelf cores are barren of nannofossils and correspond to two minor disconformities. Middle paleoshelf cores contain a mixture of samples devoid of nannofossils and those with rare specimens characterized by significant dissolution (i.e., etching). The magnitude of the decrease in carbonate cannot be explained by dilution by clastic material or dissolution resulting from the oxidation of organic matter during early diagenesis. The observed preservation pattern implies a shoaling of the calcite compensation depth (CCD) and lysocline to the middle shelf. This reduced carbonate interval is observed during the onset of the PETM on other continental margins raising the possibility that extreme shoaling of the CCD and lysocline was a global signal, which is more significant than in previous estimates for the PETM. An alternative scenario is that shoaling was restricted to the northwest Atlantic, enhanced by regional and local factors (eutrophication from rivers, microbial activity associated with warming) that exacerbated the impact of acidification on the shelf.

Bralower T. J., Kump L. R., Self-Trail J. M., Robinson M. M., Lyons S., Babila T., Ballaron E., Freeman K. H., Hajek E., Rush W., Zachos J. C., in press. Evidence for shelf acidification during the onset of the Paleocene‐Eocene Thermal Maximum. Paleoceanography and Paleoclimatology. Article (subscription required).

0 Responses to “Evidence for shelf acidification during the onset of the Paleocene‐Eocene Thermal Maximum”



  1. Leave a Comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.




Subscribe to the RSS feed

Powered by FeedBurner

Follow AnneMarin on Twitter

Blog Stats

  • 1,272,182 hits

OA-ICC HIGHLIGHTS

Ocean acidification in the IPCC AR5 WG II

OUP book