Geochemistry application of Major and Trace Elements for Analysis of Palaeo Climate of North Part of Gavkhooni Wetland

The international Gavkhoni wetland is located in Isfahan province and has an area of 470 square kilometers. This wetland is a Grabni hole which has been covered by quaternary sediments. The present study attempts to study climatic changes of north part of Gavkhoni wetland based on chemical (major and trace elements) sedimentology. Evidences of sedimentology include the study of erosion processes as well as the study of sediments such as combination and conditions of sedimentation are among the important evidences of analysis of past climatic conditions. In order to conduct the present study 7 cores ranges 1 to 2 meters were used. Data analysis is based on the geochemical methods to determine the frequency percent of the mentioned elements in each sediment sample for determining the climatic conditions of the region in that specific period of sedimentation. Analyzing four sensitive elements to the change of environmental conditions that is, Calcium, magnesium, manganese and strontium and the proportion of magnesium, manganese and strontium to calcium, revealed some results of changes of environmental conditions. According to the examined samples, a division of past climatic conditions in the region has been achieved. Based on the whole evidences, it seems that in 100 and 140- centimeter sections dry periods and in 60 and 200-centimeter sections, more humid periods have been occurred. In the first 20 centimeters of the sediments that is the closest time to the present time, borderline conditions or semi-dry conditions were observed.