Occurrence of hiatuses PH and NH 1 through NH 7 in DSDP holes ...

Miocene paleoceanographic evolution exhibits major changes resulting from the opening and closing of passages, the subsequent changes in oceanic circulation, and development of major Antarctic glaciation. The consequences and timing of these events can be observed in variations in the distribution o...

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Bibliographic Details
Main Authors: Keller, Gerta, Barron, John A
Format: Article in Journal/Newspaper
Language:English
Published: PANGAEA 1983
Subjects:
Online Access:https://dx.doi.org/10.1594/pangaea.719185
https://doi.pangaea.de/10.1594/PANGAEA.719185
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Summary:Miocene paleoceanographic evolution exhibits major changes resulting from the opening and closing of passages, the subsequent changes in oceanic circulation, and development of major Antarctic glaciation. The consequences and timing of these events can be observed in variations in the distribution of deep-sea hiatuses, sedimentation patterns, and biogeographic distribution of planktic organisms. The opening of the Drake Passage in the latest Oligocene to early Miocene (25-20 Ma) resulted in the establishment of the deep circumpolar current, which led to thermal isolation of Antarctica and increased global cooling. This development was associated with a major turnover in planktic organisms, resulting in the evolution of Neogene assemblages and the eventual extinction of Paleogene assemblages. The erosive patterns of two widespread hiatuses (PH, 23.0-22.5 Ma; and NH 1, 20-18 Ma) indicate that a deep circumequatorial circulation existed at this time, characterized by a broad band of carbonate-ooze deposition. ... : Supplement to: Keller, Gerta; Barron, John A (1983): Paleoceanographic implications of Miocene deep-sea hiatuses. Geological Society of America Bulletin, 94(5), 590-613 ...