Tectonic forcings of Maastrichtian ocean-climate evolution

• Published in: Paleoceanography
• Main Authors: Frank, T. D., Arthur, M. A.
• Other Authors: M. L. Delaney
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 1999
• Subjects: Geosciences; Multidisciplinary; Oceanography; Paleontology; Paleocene Magnetic Stratigraphy; Cretaceous-tertiary Boundary; Southern High-latitudes; Project Leg 74; Planktonic-foraminifera; Isotopic Evidence; Atlantic Ocean; Sea-water; Circulation; Paleotemperature; 260104 Sedimentology; C1; 780104 Earth sciences; Indian; Pacific; North Atlantic; Planktonic foraminifera
• Online Access: https://espace.library.uq.edu.au/view/UQ:142964

A global compilation of deep-sea isotopic records suggests that Maastrichtian ocean-climate evolution tvas tectonically driven. During the early Maastrichtian the Atlantic intermediate-deep ocean was isolated from the Pacific, Indian, and Southern Oceans; deep water formed in the high-latitude North Atlantic and North Pacific. At the early/late Maastrichtian boundary a major reorganization of oceanic circulation patterns occurred, resulting in the development of a thermohaline circulation system similar to that of the modem oceans. A combination of isotopic and plate kinematic data suggests that this event was triggered by the final breaching of tectonic sills in the South Atlantic and the initiation of north-south flow of intermediate and deep water in the Atlantic. The onset of Laramide tectonism during the mid Maastrichtian led to the concurrent draining of major epicontinental seaways. Together, these events caused cooling, increased latitudinal temperature gradients, increased ventilation of the deep ocean, and affected a range of marine biota.