Development and Demise of Mid-Oceanic Carbonate Platforms, Wodejebato Guyot (NW Pacific)

  1. G. F. Camoin5 and
  2. P. J. Davies6
  1. G. F. Camoin1,5,
  2. A. Arnaud-Vanneau2,
  3. D. D. Bergersen3,
  4. P. Enos4 and
  5. Ph. Ebren1

Published Online: 27 MAY 2009

DOI: 10.1002/9781444304879.ch3

Reefs and Carbonate Platforms in the Pacific and Indian Oceans

Reefs and Carbonate Platforms in the Pacific and Indian Oceans

How to Cite

Camoin, G. F., Arnaud-Vanneau, A., Bergersen, D. D., Enos, P. and Ebren, Ph. (1998) Development and Demise of Mid-Oceanic Carbonate Platforms, Wodejebato Guyot (NW Pacific), in Reefs and Carbonate Platforms in the Pacific and Indian Oceans (eds G. F. Camoin and P. J. Davies), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444304879.ch3

Editor Information

  1. 5

    CEREGE, Aix-en-Provence, France

  2. 6

    University of Sydney, Australia

Author Information

  1. 1

    CEREGE, CNRS UMR 6536, Université Aix-Marseille III, B. P. 80, 13545 Aix-en-Provence cédex 4, France

  2. 2

    Institut Dolomieu, Université J. Fourier, Rue M. Gignoux, 38031 Grenoble cédex, France

  3. 3

    University of Sydney, Department of Geology, NSW 2006, Sydney, Australia

  4. 4

    University of Kansas, Department of Geology, 120 Lindley Hall, Lawrence, KS 66045-4974, USA

  5. 5

    CEREGE, Aix-en-Provence, France

Publication History

  1. Published Online: 27 MAY 2009
  2. Published Print: 23 MAR 1998

ISBN Information

Print ISBN: 9780632047789

Online ISBN: 9781444304879

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Keywords:

  • mid-oceanic carbonate platform development;
  • retrogradational, progradational and aggradational sand shoals;
  • platform carbonate biostratigraphy;
  • inner elevated platform rim;
  • dissolution and cavity infillings

Summary

A model for the development and the demise of mid-oceanic carbonate platforms is based on a detailed sedimentological, palaeontological, seismic, and geochemical study of Wodejebato Guyot (Marshall Islands, NW Pacific). After a prolonged period of subaerial exposure (a few million years) characterized by the pedogenic alteration of the volcanic basement, the flooding of the platform resulted in the accumulation of skeletal sand piles near the shelf margin, rimming a volcanic island. The overlying sequence is a series of retrogradational and then progradational and aggradational sand shoals that progressively flooded the central part of the guyot. Atoll features at Wodejebato Guyot include well-differentiated depositional elevated platform rims, partly composed of early cemented organic frameworks, enclosing a central lagoon, and flanked by steep talus leading down to volcanic slopes. The subsequent development of the carbonate platform includes two successive periods of emergence: a first limited fall in sea-level and a second deeper fall in sea-level before the final drowning of the carbonate platform during Maastrichtian time. The last platform carbonate sequence corresponds to a wedge deposited during a sea-level lowstand on the outer ridge, whereas the inner part of the platform was subaerially exposed and probably karstified. After its demise, the carbonate platform sank to deep water, between the aragonite and the deeper calcite saturation limits, resulting in the dissolution of aragonite and concomitant precipitation of calcite cements, possibly throughout the Cainozoic to the present. Post-drowning deposits include phosphate–manganese crusts that formed from the late Palaeocene to the middle Eocene.

The drilling results of Leg 144 and other data indicate that there were at least three major episodes of carbonate platform drowning within the tropical Pacific, i.e. Albian, late Maastrichtian and middle Eocene. We propose that these events were caused by short-term regression–transgression cycles connected to short-term cooling events and deep oceanographic changes.