The Research On Paleoclimate Changes Since Last Interglacial Stage In Linfen Basin, Shanxi

Linfen Basin is located in the southern and eastern edge of Ordos Massif; this region is one of the areas where neotectonic movement of our country is very strong. It is in favor of recognizing the major scientific issue that the regional uplift of the Tibetan Plateau and its environmental effects to focus research on Shanxi Linfen Basin from a more extensive contact with the causes of a whole region, and there is also of great significance to reveal the paleoclimate changes of southwest of Shanxi from the record since last Interglacial at Qianfu section of Linfen Basin.Since Middle Pleistocene basin has experienced a number of lakes invaded the lake retreated, continuous sedimentary strata formed of loess-paleosol layers and layers of lake sediment distribution in each situation, and there has been abundant paleoclimate change information. Based on data processing and integrated analysis of Linfen Basin lake sediments in magnetic susceptibility, grain-size, geochemistry element, and organic matter, we picked out the paleoclimate proxies those be able to accurately reflect the region's paleoclimate change, and then analyzed the response to signal of global climate change in Linfen Basin, revealed the climate fluctuations of high temporal resolution in the last glacial, set up characters and process of the paleoclimatic evolvement in Linfen Basin since the last interglacial, and more provided a analogical material for further discussion of the evolution of climate and environment in the central and eastern region of China.Based on sedimentological analysis of Qinfudong (QFD) section, data processing and integrated analysis of Linfen Basin lake sediments in magnetic susceptibility, grain-size, chemical element composition, and organic matter, we confirmed magnetic susceptibility, <4μm content of clay, 4～63μm content of silty sand, median grain-size, content of organic matter, Rb and Sr concentrations along with Rb/Sr ratio as climate proxies to study Qianfu section, and also determined its paleoclimatic significance.According to the comparative analysis among climate Multi-proxy and interpolation during ages, combining with the sedimentological characteristics of section, time sequence since the last interglacial of Linfen Basin was established and divided into five stages: L1L3, L1S2, L1L2, L1S1 and L1L1. They are respectively corresponding to depth of 760～620cm (73～51.9kaB.P.), relatively arid and cold; 62～530cm (51.9～46.1kaB.P.), relatively worm and humid; 530～300cm(46.1～28.9kaB.P), relatively arid and cold;300～220cm(28.9～22kaB.P), relatively worm and humid; 220～0cm(22～10.3kaB.P.), worm and humid arid and cold by turns.By the impact of global climate change, Qianfu section also recorded a number of millennium-scale climate events during the last glacial which performance of the global characteristics, including sixteen warm events and seven cold events which we inferred as sixteen Dansgaard-Oescheger events, six Heinrich events (H1～H6) and the Younger Dryas during the last deglacial.