合肥盆地下蜀黄土年龄及物源探讨

A tentative discussion on the age and provenance of the Xiashu Loess in the Hefei Basin, Anhui Province

OSL测龄结果表明合肥盆地下蜀黄土(下蜀组)在中更新世晚期已开始沉积;将主量化学元素和粒度分析与西北黄土、镇江下蜀黄土、巫山黄土和宣城黄土进行对比,研究了合肥盆地下蜀黄土物源。研究结果表明,地球化学、粒度及沉积速率等均显示合肥下蜀黄土物源有别于镇江黄土及西北黄土;并从岩相古地理及古气候特征探讨了淮河沿岸及淮北地区河流相、湖相及湖沼相细粒沉积物或许是其潜在的物源。

The OSL dating results show that the deposition of the Xiashu Loess（Xiashu Formation） in the Hefei Basin began in the late period of the Middle Pleistocene. In this study, the major geochemical elements and grain sizes of the Xiashu Loess in Hefei were compared with those of Northwest（NW） loess, Xiashu Loess of Zhenjiang, Wushan Loess and Xuancheng Loess. The provenance of the Xiashu Loess in Hefei was discussed. Studies of geochemical characteristics, grain size content and deposition rate show that the provenance of the Hefei Xiashu Loess differs from that of the nearby Zhenjiang loess and the Northwest China Loess which were derived from the northern deserts. The lithofacies palaeogeography and the paleoclimate indicate that the abundant fine-grained sediments of the alluvial-lacustrine deposits in the Huaihe floodplain seem to be the major source materials of the Hefei Xiashu Loess.