中国地质2011，Vol.38Issue(3)：779-785,7.
化学风化指数和磁化率对洞庭盆地第四纪古气候变化的响应
Chemical weathering index and magnetic susceptibility of deposits and their responses to the Quaternary climate in Dongting Basin
摘要
Abstract
The drilling of ZKC1 borehole was carried out at Lianghucun in southeastern Anxiang sag.The Quaternary alluvial and lacustrine sediments in the borehole are composed of Pliocene-Early Pleistocene Huatian Formation, Early Pleistocene Miluo Formation, early-middle Middle Pleistocene Dongtinghu Formation, Late Pleistocene Potou Formation and Holocene strata.The major elements and magnetic susceptibility of the core from the borehole were analyzed systematically.According to the idea that the chemical weathering index (CWI)of terrestrial sediments has a positive correlation with temperature and humidity, and that the magnetic susceptibility has a negative correlation with temperature and humidity, the authors probed into the Quaternary climate evolution of the Dongting basin.Combined with other materials, the curve of CIA indicates that the Quaternary climatic evolution of the Dongting basin was from early to late in order of cool and dry → tropical and humid → cool and dry → tropical and humid during Early Pleistocene; cool and dry → tropical and humid → cool and dry-warm and humid→ tropical and humid during Middle Pleistocene; cool → warm and humid →cool during Late Pleistocene, and warm and humid-tropical and humid during Holocene.This climatic evolution process coincides basically with climatic change indicated by sporopollen assemblages of the core from the ZKC1 borehole, and also accords with Quaternary climatic variations of eastern China, which suggests that the CWI of the sediments shows a good responses to the Quaternary climate evolution.Curves and correlation coefficient of -0.32 between CWI and magnetic susceptibility of the sediments show that the magnetic susceptibility has a negative correlation with CWI, which suggests that temperature and humidity controlled evidently the magnetic susceptibility.Impacted probably by the uplift and subsidence of the basin, the curve of the magnetic susceptibility fails to show the same phasic variations as CWI.关键词
化学风化指数/磁化率/第四纪/气候演变/洞庭盆地Key words
chemical weathering index/ magnetic susceptibility/ Quaternary/ climatic evolution/ Dongting Basin分类
天文与地球科学引用本文复制引用
柏道远,李长安,陈渡平,周柯军,黄文义..化学风化指数和磁化率对洞庭盆地第四纪古气候变化的响应[J].中国地质,2011,38(3):779-785,7.基金项目
中国地质调查局地质大调查项目(1212010610706)和国家自然科学基金项目(40771213)资助. （1212010610706）
