Origin and Correlation of Disconformity Surfaces and Marker Beds, Nahr Umr Formation, Northern Oman
Adrian Immenhauser, Wolfgang Schlager, Stephen J. Burns, Robert W. Scott, Tini Geel, Jens Lehmann, Sjerry Van Der Gaast, Liselotte J. A. Bolder-Schrijver, 2000. "Origin and Correlation of Disconformity Surfaces and Marker Beds, Nahr Umr Formation, Northern Oman", Middle East Models of Jurassic/Cretaceous Carbonate Systems, Abdulrahman S. Alsharhan, Robert W. Scott
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During Aptian to Albian times a major influx of terrigenous material from the emerged Arabian Shield led to the deposition of the Nahr Umr Formation within the intracratonic Bab Basin. This argillaceous facies interfingers in northern Oman with sediments shed from reefal complexes. We studied a 100 km transect across the zone of facies intercalation extending from the margin of the Neo-Tethys (northern Jabal Akhdar) into the fringes of the Bab Basin in northern Oman (Foothills). The age of formation boundaries and key beds and surfaces in a reference section (Wadi Bani Kharus; I) was dated by use of the graphic correlation method. Graphic correlation indicates that the Nahr Umr Formation is of uppermost Aptian to Upper Albian age. Two types of stratigraphic markers were recognized: limestone marker beds, successions, and disconformity surfaces. Calcareous marker beds are probably related to increased carbonate production during sea-level lowstands. Investigations of the geochemistry (stable isotopes, fluid inclusions) and sediment petrography of limestones beneath disconformities revealed that they are of combined submarine and subaerial origin. Evidence for a subaerial exposure stage is recognized along the basin margin (northern and southern Jabal Akhdar) but is found less frequently in the basinward settings of the Foothills. Marker-bed successions and disconformity surfaces are correlated throughout the sections and indicate coeval deposition of the Nahr Umr Formation in northern Oman.
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Middle East Models of Jurassic/Cretaceous Carbonate Systems
This volume will interest tectonic modelers, stratigraphers, sedimentologists, and explorationists. It is the product of the international conference of “Jurassic/Cretaceous Carbonate Platform-Basin Systems, Middle East Models” that was convened in December 1997 jointly by SEPM (Society for Sedimentary Geology) and the United Arab Emirates University in Al Ain, United Arab Emirates. The twenty-three papers present new data and interpretations arranged in three sections: 1) sequence stratigraphy, cyclostratigraphy, chronostratigraphy, and tectonic influences, 2) depositional and diagenetic models of carbonate platforms, and 3) hydrocarbon habitat and exploration/development case studies. New tectonic models of the Arabian Basin, new stratigraphic and sequence stratigraphic reference sections, new geochemical and source rock data, and new reservoir data are presented. New geologic models make this set of papers relevant to geoscientists working outside of Arabia also.