Diagenesis of Calcium Sulfate: A Review

Introduction 4
Mineralogy and Optical Properties 4
Gypsum 4
Anhydrite 4
Gypsum/Anhydrite Equilibria Relations 5
The Anhydrite Problem 5
Experimental Crystallization of Anhydrite 7
Alteration of Gypsum to Anhydrite 9
Volume Relationship 9
RECENT ANHYDRITE NODULES 9
Occurrence 9
Crystal Fabrics 10
Discussion 11
Burial Conversion of Gypsum to Anhydrite 11
Calcium Sulfate Leaching and Porosity Development 12
Moldic Porosity 13
Evaporite Solution Breccias 15
Calcium Sulfate Leaching and Dolomite Calcitization 17
Models of Dedolomitization 17
Dedolomite Textures 18
Calcium Sulfate Leaching with replacement 21
Calcitized Anhydrite 21
Silicified Calcium Sulfate 22
Calcium Sulfate Cementation 26
Crystal Fabrics of Gypsum and Anhydrite 26
Diagenetic Environments of Gypsum Cement 28
Diagenetic Environment of Anhydrite Cement 29
References 30

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