Geochemical, Sedimentological and Mineralogical Characterization of Surficial Sediments in Eynak Marsh (North of Iran)

Abstract

A multidisciplinary study of the sedimentology, geochemistry andmineralogy has been conducted to understand the linkage between marsh andalluvial sediments and also their potential sources in Eynak marsh, North ofIran. The influence of the upstream potential sources on recent sedimentgeochemistry has been discussed based on geochemical,sedimentological and mineralogical results. A spatial grain size distributionstudy was carried out to investigate the hydrodynamic and deposition system ofthe marsh. So, the surficial sediment sampling was carried out to describe thesedimentological parameters and elemental geochemistry of sediments in Eynakmarsh. Mineralogical complexes are mainly made up of felsic minerals such asquartz, calcite, feldspar, pyrite, mica, and clay minerals (in very low values)indicated by high amounts of Al, Ca, and Ni. As expected, the mineralogy ofsediments is controlled mainly by the rock formations. Also sediment textures arecontrolled by the hydrodynamic condition in the marsh. So its distribution has beeninfluenced by distance from the entrance sediments to Eynak marsh. The resultsshowed that there are no enrichments related to fine grain sedimentdistributions. An association of Al with the trace elements such as Sc, Y, La,Ce, and Zr indicates that their distributions are mainly controlled by thefelsic rocks in the upstream. On the other side, due to the waste waterentrance to the marsh, Ni and Pb concentration could be under the effects ofanthropogenic activities around the marsh. Results represented high values forMn concentration (min 462, max 1784 and average 1037 ppm) and it showed asignificant correlation with Ca, Sr, and Mg. A redox habitat and constantlycalm hydrodynamic circumstance in the study area, likely cause highconcentration of Ca, Sr, and Mg, and Mn. And they are representing negativecorrelations with some elements such as Al, Be, Fe, K, and Na.