Beach sedimentary processes, facies and erosion surfaces detected by GPR and coring survey in southern margin of Caspian Sea, Kouchesfahan area

The coastal areas constitute a very sensitive geomorphic domain constantly subjected to dynamic coastal sedimentary processes. The textural and lithological characteristics of subsurface sediments along with Ground Penetrating Radar (GPR) data collected along the southern margin of Caspian Sea, Kouchesfahan area were used to understand the depositional environments, sedimentary structures and the provenance of sediments. These studies used to assess soil salinity, determining the depth to subsurface horizons, mapping soil types, characterizing soil water content and flow patterns, variations in soil texture, compaction, organic matter content, and stratigraphic layers or bedrock. This GPR survey delineated a variety of the radar surfaces and radar facies which reflects not only large scale sedimentary architecture, but depositional facies. A 25 km GPR profile across the beach ridges reveals the sedimentary structures and stratigraphic units. In order to calibrate the seismic data with characteristics facies obtained using an Auger involves ten cores to lengths of 4 and 5 m were prepared. The data from these two methods were compared. The GPR profile shows that there are many more erosion surfaces in the subsurface than beach ridges on the surface. The internal sedimentary structures like tangential, parallel, concave and convex upward stratifications could also be visualized from the GPR profiles. These are bounding surfaces separating the radar facies outline beach ridge, wash over, coastal dune, swale depositional environments and three soil horizons.