Seismic expressions of a Miocene prograding carbonate margin, Mut Basin, Turkey

摘要

The detailed stratigraphic architecture of a Miocene intraplatform prograding carbonate margin, outcropping in Mut Basin, Turkey, was used to build two-dimensional synthetic seismograms by normal ray-tracing and finite-difference, exploding-reflector methods. The synthetic seismic models at various frequencies display the overall prograding architecture of the 1.5-km (0.95-mi) x 250-m (820-ft) prograding margin, even at 40-Hz frequency; however, most of the complex stratigraphic architecture is below standard seismic resolution. Sigmoidal outcrop geometries create complex, shingled, seismic reflections that contain pseudodownlap, pseudotoplap, and various truncations at 40-Hz frequency. In addition, reflections that do not correspond to any impedance contrast are generated by a tuning effect within the clinoform. Interference patterns created by the complex impedance distribution create reflections that change phase laterally and cross stratigraphic timelines. Several high-impedance coral buildups at the slope break and on the platform top cause reflections to change phase and amplitude along the timeline. In addition, lateral-impedance variations generate mounded reflections that, in places, cross timelines and resemble seismic images for buildups or anticlinal structures.