Cenozoic carbonate accumulation and compensation depth changes in the Indian Ocean

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doi: 10.1029/GM070p0311
Author(s): Peterson, L. C.; Murray, D. W.; Ehrmann, W. U.; Hempel, P.
Author Affiliation(s): Primary:
University of Miami, Rosenstiel School of Marine and Atmospheric Science, Miami, FL, United States
University of Michigan, United States
University of Wales College of Cardiff, United Kingdom
Bundesanstalt für Geowissenschaften und Rohstoffe, Federal Republic of Germany
Lamont-Doherty Geological Observatory of Columbia University, United States
Brown University, United States
Alfred-Wegener-Institut fü Polar- und Meeresforschung, Federal Republic of Germany
GEOMAR, Federal Republic of Germany
Volume Title: Synthesis of results from scientific drilling in the Indian Ocean
Volume Author(s): Duncan, Robert A., editor; Rea, David K.; Kidd, Robert B.; von Rad, Ulrich; Weissel, Jeffrey K.
Source: Synthesis of results from scientific drilling in the Indian Ocean, edited by Robert A. Duncan, David K. Rea, Robert B. Kidd, Ulrich von Rad and Jeffrey K. Weissel. Geophysical Monograph, Vol.70, p.311-333. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0065-8448. ISBN: 978-1-118-66803-0 CODEN: GPMGAD
Note: In English with English summary. 116 refs.; illus., incl. strat. cols., sketch map
Summary: Quantitative estimates of the flux of biogenic carbonate to the sea floor, and of the rates and patterns of its subsequent accumulation, are key components to understanding past ocean history. As one of its principal objectives, Leg 115 of the Ocean Drilling Program drilled a depth transect of sites in the western equatorial Indian Ocean for detailed studies of the carbonate system. Here, we review the major results of the Leg 115 program and compare them with data on carbonate accumulation rates derived from eighteen additional sites drilled during the remaining legs of the Indian Ocean campaign. Regional accumulation patterns are found that are variably affected by the changing balance between productivity and dissolution, and by physical processes such as erosion. In the Paleogene, tectonic activity and changing bottom circulation resulted in a patchy record of carbonate sedimentation across the basin. In the early and middle Miocene, greatly reduced carbonate accumulation in the equatorial region was the result of a shallow CCD and a probable drop in surface productivity. Winnowing was also common at shallow Indian Ocean sites during this interval, suggesting a more vigorous intermediate water circulation. At about 8-9 Ma, carbonate accumulation rose abruptly in shallow low latitude sites and a strong dissolution gradient was first established in the water column. Arabian Sea sites at this time show accumulation patterns similar to Indo-Pacific sites far removed from the direct influence of monsoonal up welling, suggesting that carbonate deposition in this region is responding more to global-scale processes than to the localized influence of the monsoon. A comparison of the Neogene depth history of the CCD to the record of eustasy supports the argument that sea level exerts a first-order control on the deposition of carbonate through shelf-basin fractionation. Regional variations in carbonate accumulation above the CCD are probably more directly affected by carbonate production rates in the overlying surface waters.
Year of Publication: 1992
Research Program: ODP Ocean Drilling Program
Key Words: 06 Petrology, Sedimentary; Calcium carbonate; Carbonate compensation depth; Carbonates; Cenozoic; Exmouth Plateau; Indian Ocean; Leg 115; Leg 117; Leg 119; Leg 122; Ocean Drilling Program; Ocean circulation; Ocean floors; Paleo-oceanography; Productivity; Sea-level changes; Solution; Tertiary; Wombat Plateau
Coordinates: S131002 N050454 E0734953 E0590100
N160748 N182912 E0604438 E0572212
S684114 S492407 E0855147 E0713936
S203512 S163357 E1153337 E1121231
Record ID: 2007093168
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