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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 66 (1982)

Issue: 5. (May)

First Page: 542

Last Page: 542

Title: Deep-Water Evaporites: Detrital, Authigenic, or Diagenetic?: ABSTRACT

Author(s): Wayne M. Ahr

Article Type: Meeting abstract

Abstract:

The thought of "deep-water" evaporites commonly conjures images of hypersaline starved basins, chemical precipitation of evaporite minerals in the water column or at the sediment-water interface, and cyclically laminated salts. It is implicit in this model that the evaporite fabrics reflect stagnant, unstirred, abiotic conditions, but deep-water evaporites in the Messinian of the Sicilian basin include evaporite turbidites and resedimented clastic evaporites with wholly different petrographic characteristics and sedimentary structures. Detrital dolomites in the Onondaga Limestone and in the Cretaceous of the western United States reflect clastic depositional histories and yet may have strong diagenetic overprints that obscure the original depositional textures.

Diagenetically altered, sandy, anhydritic dolomites from the Bell Canyon Formation in Texas provide examples of deep-water detrital, evaporitic carbonates with a depositional history indicated principally by the included siliciclastics and a diagenetic history indicated first by "groundmass" versus pore-filling dolomite crystal fabrics and second by nodular versus pore-filling and replacement anhydrite. Comparisons between the Bell Canyon deep-water anhydritic dolomites and other deep-water evaporites is useful in making the distinction between clastic, penecontemporaneous authigenic, and later diagenetic origins.

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