Enhanced clay formation key in sustaining the Middle Eocene Climatic Optimum.

ABSTRACT: The Middle Eocene Climatic Optimum (around 40 million years ago) was a roughly 400,000-year-long global warming phase associated with an increase in atmospheric CO₂ concentrations and deep-ocean acidification that interrupted the Eocene's long-term cooling trend. The unusually long duration, compared with early Eocene global warming phases, is puzzling as temperature-dependent silicate weathering should have provided a negative feedback, drawing down CO₂ over this timescale. Here we investigate silicate weathering during this climate warming event by measuring lithium isotope ratios (reported as δ⁷Li), which are a tracer for silicate weathering processes, from a suite of open-ocean carbonate-rich sediments. We find a positive δ⁷Li excursion-the o

SUBMITTER: Krause AJ 

PROVIDER: S-EPMC10409649 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature