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Xavier Janson1, Gregor P. Eberli1
(1) University of Miami, Comparative Sedimentology Laboratory, Miami, FL

Abstract: 2D/3D geometries of tertiary prograding margins, Mut basin, Turkey: interplay between accommodation and production

In south central Turkey, great exposures of a Middle Miocene carbonate platform display exceptionally well-preserved depositional geometries that are controlled by accommodation, energy direction and type of sediment producers. In addition, they allow to exam the importance of section direction in seismic interpretation. The investigated area is a 20 km wide composite carbonate system that consists of a barrier reef and several small attached platforms with reefal crests. These prograding platforms are attached to the adjacent basement highs. During the late Burdigalian and the Langhian, two platforms are prograding towards each other into the back-barrier depression. On a large scale, the prograding margins show initially steep clinoforms that progressively flattens as the depression is filled. Ultimately the two margins fill the depression and coalesce. Clinoform geometries are controlled by the changing accommodation rate/sedimentation flux ratio. Even if they share the same accommodation history, the two facing margins have different clinoforms geometries due to differences in carbonate production. The windward margin exhibits flatter clinoforms due to a higher reefal production which produce a greater amount of debris that accumulate at the toes of the clinoforms. In contrast, the leeward margin has weaker reef development associated with steeper geometries and clinoforms toes that rapidly thins-out into the distal thinner-bedded deposits. Investigating the architecture of clinoforms in three dimensions reveals striking differences in clinoform geometries depending on section direction. This section effect reveals potential pitfalls in geometrically based seismic stratigraphic interpretation.

AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana