Reconstruction of east–west deep water exchange in the low latitude Atlantic Ocean over the past 25,000 years ...

• Main Authors: Howe, JNW, Piotrowski, AM, Hu, R, Bory, A
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2017
• Subjects: neodymium isotopes; Last Glacial Maximum; eastern Atlantic; western Atlantic; North Atlantic Deep Water; North Atlantic
• Online Access: https://dx.doi.org/10.17863/cam.7064; https://www.repository.cam.ac.uk/handle/1810/261844

Radiogenic neodymium isotopes have been used as a water mass mixing proxy to investigate past changes in ocean circulation. Here we present a new depth transect of deglacial neodymium isotope records measured on uncleaned planktic foraminifera from five cores spanning from 3300 to 4900 m on the Mauritanian margin, in the tropical eastern Atlantic as well as an additional record from 4000 m on the Ceara Rise in the equatorial western Atlantic. Despite being located under the Saharan dust plume, the eastern Atlantic records differ from the composition of detrital inputs through time and exhibit similar values to the western Atlantic foraminiferal Nd across the deglaciation. Therefore we interpret the foraminiferal values as recording deep water Nd isotope changes. All six cores shift to less radiogenic values across the deglaciation, indicating that they were bathed by a lower proportion of North Atlantic Deep Water during the Last Glacial Maximum (LGM) relative to the Holocene. The eastern Atlantic records ...