Skip to Main Content
Book Chapter

Climatic Control of Dolomitization, Seroe Domi Formation (Pliocene), Bonaire, N.A.

By
Duncan F. Sibley
Duncan F. Sibley
Michigan State University, EastLansing, 48824
Search for other works by this author on:
Published:
January 01, 1980

Abstract

Dolomitization of sediments may be controlled, in part, by their pre-dolomitization diagenetic history. The Seroe Domi Formation (Pliocene) dolomites on Bonaire underwent a period of minor fresh water diagenesis prior to dolomitization. During this initial stage of diagenesis, a small amount of low Mg-calcite cement formed. Unaltered high Mg-calcite and aragonite skeletal fragments were replaced during dolomitization and low Mg-calcite was, at first, inert and later occasionally dissolved. The indusion of calcite cement crystals and crystal molds in dolomite rhombs, the presence of calcite zones in dolomite rhombs, and the preservation of limestone fragments in dolomitized breccias demonstrate that low Mg-calcite was not replaced during the initial dolomitization. Cloudy centers and clear rims formed when the dolomitizing fluid changed from near saturation with respect to calcite (cloudy centers due to inclusions and molds) to undersaturation with respect to calcite (inclusion and mold-free rims).

The concentration of Na+ in these dolomites is approximately 280 ppm and the δ18O values range from +2.0 to +4.1% PDB. These data indicate that the dolomitizing fluid was low in Na+ (relative to seawater), but isotopically heavier than most ground water and, therefore, probably an evaporation concentrated fresh water.

The Seroe Domi Formation is dolomitized on Curaçao and Aruba as well as on Bonaire. The data suggest that dolomitization may be climatically controlled. In humid climates, a sediment in the fresh water-seawater phreatic mixing zone may undergo rapid calcification due to the high PCO2 in the ground water. In arid climates, the water will have a lower PCO2 due to limited soil development resulting in slower calcification and, therefore, increased chances for dolomitization.

You do not currently have access to this article.

Figures & Tables

Contents

SEPM Special Publication

Concepts and Models of Dolomitization

Donald H. Zenger
Donald H. Zenger
Pomona College, Claremont, California
Search for other works by this author on:
John B. Dunham
John B. Dunham
Union Oil Research Center, Brea, California
Search for other works by this author on:
Raymond L. Ethington
Raymond L. Ethington
Ethington, University of Missouri-Columbia
Search for other works by this author on:
SEPM Society for Sedimentary Geology
Volume
28
ISBN electronic:
9781565761582
Publication date:
January 01, 1980

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal