Foraminiferal stable isotopes and physical properties from North Atlantic sediment cores for the past 3.2 million years

We compare the isotope and lithological proxies at Site U1308 with other North Atlantic records (e.g., sites 982, 607/U1313, and U1304) to reconstruct the history of orbital and millennial-scale climate variability during the Quaternary.

The Site U1308 record documents a progressive increase in the intensity of Northern Hemisphere glacial–interglacial cycles during the late Pliocene and Quaternary, with mode transitions at ~2.7, 1.5, 0.9, and 0.65 Ma. These transitions mark times of change in the growth and stability of Northern Hemisphere ice sheets. They also coincide with increases in vertical carbon isotope gradients between the intermediate and deep ocean, suggesting changes in deep carbon storage and atmospheric CO2.