Paleocene/Eocene boundary changes in atmospheric and oceanic circulation; a Southern Hemisphere record

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doi: 10.1130/0091-7613(1992)020<0015:PEBCIA>2.3.CO;2
Author(s): Hovan, Steven A.; Rea, David K.
Author Affiliation(s): Primary:
Univ. Mich., Dep. Geol. Sci., Ann Arbor, MI, United States
Volume Title: Geology (Boulder)
Source: Geology (Boulder), 20(1), p.15-18. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0091-7613 CODEN: GLGYBA
Note: In English. 24 refs.; 1 table, chart, sketch map
Summary: Deep Sea Drilling Project (DSDP) Site 215 provides an expanded section across the Paleocene/Eocene boundary, the most complete mid-latitude sequence from a Southern Hemisphere location in the Indo-Pacific area. The events of this transition occurred during a span of about 1.2 m.y. Oxygen isotope values derived from benthic foraminiferal calcite decrease by about 1.0ppm, a decrease most likely related to warming of deep ocean waters. Turnovers of benthic foraminifera accompany δ18O changes and culminate in the predominant extinction event at the end of the Paleocene Epoch. Carbon isotope ratios also shift dramatically toward lighter values near the end of the Paleocene, beginning about 0.45 m.y. after oxygen isotope values start to change. The intensity of Southern Hemisphere atmospheric circulation as recorded by grain sizes of eolian particles shows a large and rapid reduction beginning another 0.45 m.y. later. A significant reduction of zonal wind strength at the Paleocene/Eocene boundary, until now observed only at Northern Hemisphere locations, appears to have been a global phenomenon related to decreased latitudinal thermal gradients occasioned by more effective poleward heat transport via the deep ocean.
Year of Publication: 1992
Research Program: DSDP Deep Sea Drilling Project
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Benthic taxa; Biostratigraphy; C-13/C-12; Carbon; Cenozoic; DSDP Site 215; Deep Sea Drilling Project; Eocene; Foraminifera; Grain size; Indian Ocean; Invertebrata; Isotopes; Leg 22; Lithostratigraphy; Lower Eocene; Marine sediments; Microfossils; O-18/O-16; Oxygen; Paleo-oceanography; Paleoatmosphere; Paleocene; Paleocirculation; Paleogene; Protista; Sedimentation; Sediments; Southern Hemisphere; Stable isotopes; Stratigraphic boundary; Stratigraphy; Tertiary; Transport; Upper Paleocene; Wind transport
Coordinates: S080718 S080718 E0864730 E0864730
Record ID: 1992007363
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