Abstract: Chemostratigraphy of Carbonate-Evaporite Successions from the Southern Arabian Gulf

PEEBLES, ROSS G., JOHN MCBRIDE, and MURIEL SHANER

Stratigraphic correlation and age dating of the carbonate-evaporite successions of the Upper Jurassic of the Arabian Gulf have been problematic due to the paucity of stratigraphically significant fossils. As a result, much of the high-resolution stratigraphic correlation of these successions is based strictly on wireline log signatures. There exists a need for a stratigraphic methodology that is independent of biostratigraphy and applicable to both carbonates (limestone and dolomite) and evaporites. Chemostratigraphy uses the results of isotopic and elemental analyses to characterize a stratigraphic succession and can provide high resolution correlation. We have developed chemostratigraphic frameworks for the Upper Jurassic Arab Formation and Miocene Gachsaran Formation. Samples from these carbonate-evaporite successions were analyzed for carbon, oxygen, sulfur, and strontium isotope ratios as well as for trace element composition. Sample material included limestones, dolostones, and evaporites (anhydrite and gypsum), representing a full suite of arid coastal depositional and diagenetic facies. Modern sediments and waters from the Abu Dhabi coastal zone were also analyzed for comparison and correlation with the ancient material.

In addition to correlation and dating, our chemostratigraphic frameworks aided in the identification of sequence and parasequence boundaries, condensed sections, and in the location of paleowatertable horizons that influenced diagenesis.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria