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

摘要

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