Abstract
The importance of wetlands as unique
environments and rich in various elements from an environmental point of view
is increasing every day. In this research, the grain size and geochemistry of
Quaternary sediments in Saghalak-Sar lagoon, as one of the wetlands in Guilan
province, north of Iran, were investigated. For these propose, 74 surface and
subsurface samples of the above sediments were collected and analyzed for grain
size and finally, frequency of major elements and sub-elements oxides was
determined by ICP and XRF, respectively. The granulometery results showed that
the sediments can be classified into eight sedimentary classes including
slightly gravelly muddy sand, slightly gravelly sandy mud, sandy mud, gravelly
muddy sand, gravelly mud, Slightly Gravelly Sandy Mud, and gravelly sand.
Surface adsorption of sediment samples are moderate - weak and the tilting in
most samples is negative towards negative coarse grains. The frequency of
sediment populations in the region is not same so, the mutation population is
the most frequent in the majority of the samples. Based on the results of
texture analyses, these sediments are probably transmitted to the basins by the
river or muddy streams. Also, based on the compatibility of wetland samples on
the two-axial diagrams of the main elements oxides, i.e., Fe2O3 + MgO versus Al2O3/
SiO2 and TiO2 and log (K2O / Na2O)
versus SiO2, as well as the triangular diagrams of the sub-elements
Zr, Th, La, and Sc, it seems that the above sediments are more belong to the
range of oceanic arc islands and continental arcs, and are composed of
subduction rocks.
Keywords:
Wetland,Sediment, Saghalak-Sar, Tectoinic