| چکیده انگلیسی مقاله |
Lakes are very interesting sedimentary environments for the study of ancient climate, changes in sedimentary environments and lake level changes. Lake Zeribar is situated in the Zagros Mountains, Kurdistan, Iran. The main purpose of this research is to examine grain size sediments, geochronology and clay mineralogy accumulated in Zeribar Lake in order to check the water level fluctuations, climatic and environmental changes during the Holocene. Sedimentological and geochemical analyses included sediments grain size and clay mineralogy. The results of the data analysis suggests the existence of warm and wetter climate, increased spring rains, episode of higher lake water level, existence of fresh-water conditions, prevalence of high-energy condition, dominance of erosional processes, seasonal supply of detritus, inflows strength and dominance of chemical weathering about 8950-6870 and 5500-3170 cal yr BP. The results also suggest the existence of dry climate, reduced rainfall, drought occurrence, lake-level lowering, prevailing low-energy condition, absence of seasonal supply of detritus, decreased tidal changes and dominance of physical weathering about 6870-5500 and 3170-1300 cal yr BP. Further, during the late Holocene i.e., 3170-1300 cal yr BP, irregular occurrence of water-level variations of Zeribar, might be attributed to the effects of precipitation changes, occasional lake overflows and perhaps human activities. |