Identifying provenance of South Caspian coastal sediments using mineral distribution pattern

The provenance of southern Caspian coastal sediments was investigated based on light and heavy mineral distribution. Optical mineralogy and grain size analysis were performed on 44 surficial sediments and 9 samples from river mouths. The heavy mineral suite was primarily composed of ilmenite, magnetite, pyroxene, apatite, zircon and garnet, while light minerals included quartz, plagioclase, orthoclase and carbonate fragments. The mineral assemblage and mineral statistical analyses reflect significant differences in the type of riverine inputs to the nearshore zone. Eastern coast sediments are rich in light minerals and carbonate fragments derived mainly from the erosion of the Kopet-Dagh Mountains. The central west coast is dominated by heavy minerals, primarily ilmenite and magnetite, that are supplied by the Sefidrud River. The moderate abundance of light minerals in the central region results from the sediment flux of the rivers that drain the Cainozoic and Quaternary volcanic coverage and Mesozoic sedimentary deposits. The western coast receives sediment from the small rivers of west Alborz and the southward longshore drift, in which heavy minerals also form the majority.