Early Maastrichtian stable isotopes: changing deep water sources in the North Atlantic?

• Main Authors: Friedrich, Oliver, Herrle, Jens O, Kößler, Peter, Hemleben, Christoph
• Format: Dataset
• Language: English
• Published: PANGAEA 2004
• Subjects: 44-390A; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg44; North Atlantic
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.694724; https://doi.org/10.1594/PANGAEA.694724

We propose that the observed short-term stable isotope fluctuations reflect changes in high- and low-latitude intermediate to deep water sources, based on a high-resolution stable isotope record of planktic and benthic foraminifera from the Early Maastrichtian (~71.3 to ~ 69.6 Ma) of Blake Nose (DSDP Site 390A, North Atlantic). Sources of these waters may have been the low-latitude eastern Tethys and high-latitude North Atlantic. Changes in intermediate to deep water sources were probably steered by eccentricity-controlled insolation fluctuations. Lower insolation favored the formation of high-latitude deep waters due to positive feedback mechanisms resulting in high-latitude cooling. This led to a displacement of low-latitude deep waters at Blake Nose. Higher insolation reduced intermediate to deep-water formation in high latitudes, yielding a more northern flow of low-latitude deep waters.