جغرافیا و توسعه (Jun 2019)
Heinrich Climatic Events in North West of Iran in Late Pleistocene
Abstract
Aims of This research is investigation and reconstruction of climate change during quaternary period according to Urmia Lake terraces and we use elevation changes of this lake as indicator of climate change. 14 lake terraces were found during field work. Elevation of this lake terraces are between 1298 to 1365 meter above mean sea level. Absolute age of 6 lake terraces determined using C14 analysis. Age of this lake terraces are between 35850 to 54150 years ago. According to dating results and elevation changes of Urmia Lake terraces, we calibrate this results with climate changes during late Pleistocene we reconstruct climate conditions in this area. Age of lake level rise and formation of the Urmia lake terraces belong to late Pleistocene and synchrony to Wurm Gelation Period in north of Europe. Age of four lake terraces synchro to Heinrich event 5 and 4 and correlate to transgression of glacial in north of Europe and this evidence is the first evidence of Heinrich Events in Iran. Decrease of temperature and glaciation periods in north of Europe in late Pleistocene and Heinrichs events synchronal to lake level rise in the Urmia lake and shows effects of this intensive climate change in this region. Results present rainy periods during late Pleistocene and decrease in evaporation and temperature and increase in precipitation in this region. Increasing in River discharge lead to lake level rise and formation of lake terraces in the Urmia lake during late Pleistocene
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