Record Of Palaeoenvironment And Palaeoclimate Since Last Interglacial From Xinghua Core At Northern Jiangsu Basin

The continuous Quaternary sedimentary sequences in the Northern Jiangsu basin contain abundant information to reconstruct regional palaeoenvironmental changes, which was mainly regulated by the East Asian Monsoon. The top-most 25 m lacustrine sediments of the obtained 350 m core from Xinghua, close to the depocenter, recorded the environmental evolution history since the last interglacial.Lithological, sedimentologyical analysis, including mean grain-size, Md-So scattered diagram, Probability accumulative curve and Frequency curve, testified that lacustrine environment predominated the top 25 m of xinghua core. The relatively low-energy environment were interrupted by floods, which occasionally transported coarse grains into the lake.Time sequence of the 25 m core was established based on ~14C dating, comparison of magnetic susceptibility curve and pollen record with SPECMAP curve. The result shows that last interglacial spans the interval at the depth from 25m to 17m, Last glacial spans the interval from 17m to 5.8m and the upper-most 5.8 m were deposited during Holocene. Multi-proxy curves can be well correlated to the SPECMAP curve, and five stages were distinguished accordingly from MIS5 to MIS1. They are respectively corresponding to depth of 25~17m (124.2~76.4ka B.P.), relatively humid; 17~13.5m (76.4~55.5ka B.P.), relatively arid; 13.5~8.5m (55.5~25.6ka B.P.) , relatively humid; 8.5~5.8m (25.6~10ka B.P.) relatively arid; and 5.8~0m( 10~0ka B.P.), relatively humid. Meanwhile, six cold (H1~H6) events were identified during the last glacial, but need further testifying.Comparison of obtained record from the top 25 m core with records of polar ice cores, typical loess profiles and deep sea cores shows that the evolvement of palaeoenvironment and palaeoclimate in Northern Jiangsu basin was consistent with global environmental alternations, but its own characteristics were recognized as well.