Malformed seashells, ancient sediment provide clues about Earth’s past

Scanning electron microscope images of tiny, malformed planktonic seashells. Credit: Gabby Kitch

Nearly 100 million years ago, the Earth experienced an extreme environmental disruption that choked oxygen from the oceans and led to elevated marine extinction levels that affected the entire globe. 

Now, in a pair of complementary new studies, two Northwestern University-led teams of geoscientists report new findings on the chronology and character of events that led to this occurrence, known as Ocean Anoxic Event 2 (OAE2), which was co-discovered more than 40 years ago by late Northwestern professor Seymour Schlanger. 

By studying preserved planktonic microfossils and bulk sediment extracted from three sites around the world, the team collected direct evidence indicating that ocean acidification occurred during the earliest stages of the event, due to carbon dioxide (CO2) emissions from the eruption of massive volcanic complexes on the sea floor.

Northwestern Now, 19 January 2023. Press release.

  • Reset


OA-ICC Highlights

%d bloggers like this: