A Late Pleistocene-Holocene multi-proxy record of climate variability in the Jazmurian playa, southeastern Iran

Abstract

We present a multi-proxy record from a 5-m long sediment core from the Jazmurian playa in southeastern Iran to provide insights into globally-recognized major climatic events since the Last Glacial Maximum (LGM). In particular, we examined how variability in the Indian Ocean Summer Monsoon (IOSM) and Mid-Latitude Westerlies (MLW) contribute to distinct environmental changes in this arid to hyper-arid region in the interior of West Asia. While interior West Asia showed cold windy conditions during the LGM and post-LGM, southeast Iran experienced quiescent conditions similar to south Asia. The presence of fine-grained sediments, low magnetic susceptibility, and a decrease in aeolian inputs from ca. 21 to 14 cal kyr BP, suggests that effects of both wind and precipitation were minimal during these quiescent conditions. Increased fluvial inputs, coupled with a low abundance of evaporite minerals in Jazmurian sediments, indicated a greater influence of the IOSM between 14 and 13.2 cal kyr BP. In contrast, the Jazmurian playa was dry and dusty between 13.2 and 11.4 cal kyr BP, as reflected by an increase in aeolian sands, and the presence of evaporite minerals. This was followed by a period of strong IOSM activity during the early Holocene, coinciding with higher fluvial input ca. 11.4 cal kyr BP. The early Holocene in southeast Iran was wetter than other analogs in south Asia because of inputs from both IOSM and MWL. Several intense dry periods with sharp increases in aeolian inputs occurred after the early Holocene, due to the southward migration of the Intertropical Convergence Zone. Precipitation sources changed from a monsoon-dominated regime to one influenced mainly by the MLW during the late-Holocene. These results show that palaeoenvironmental changes in the Jazmurian playa, located at the border of IOSM and MLW zones, were primarily governed by global and regional paleoclimatic changes.