鄂东南咸宁北部冲洪积物的ESR年代及意义  

ESR Dating and Significance of Alluvial Proluvial Deposits in the Xianning Area,Southeast Hubei

作　　者：王令占 杨博 涂兵 WANG Ling-Zhan;YANG Bo;TU Bing(Wuhan Center of China Geological Survey(Central South China Innovation Center for Geosciences),Wuhan,430205,Hubei,China)

机构地区：[1]中国地质调查局武汉地质调查中心(中南地质科技创新中心),武汉430205

出　　处：《华南地质》2021年第2期127-135,共9页South China Geology

基　　金：中国地质调查局地质调查项目(DD20211385、DD20160030-3)联合资助。

摘　　要：地处幕阜山西北缘低山丘陵与江汉平原过渡部位的咸宁市北部,分布着大面积的冲洪积物,与江汉-洞庭盆地充填演化密切相关。通过野外路线地质调查和工程地质钻探,查明了冲洪积物的分布范围及发育特征,以泥质充填为主、砾石分选差、磨圆差、混杂堆积等特征表明其为近源快速堆积。ESR年代学测试结果显示,冲洪积物形成于早更新世晚期至中更新世中期,具多期活动特征。结合前人对江汉-洞庭盆地周缘冲洪积扇堆积的研究,认为在江汉-洞庭盆地充填演化过程中,盆地周缘水系由山区进入盆地时普遍发育冲洪积扇堆积,其活动时代不仅限于早更新世,而是一直持续至中更新世中期。There are large-scale alluvial proluvial deposits in the northern Xianning City where is the transi-tional area between the hilly region on the northwestern margin of the Mufu Mountain and the Jianghan-Dong-ting Plain,and are closely related to the filling evolution of the Jianghan-Dongting Basin.Through the field route geological survey and engineering drilling,the distribution and development of the alluvial proluvial deposits were investigated.They are mostly argillaceous with poorly sorted and rounded gravels,and their diamicton indicates a near-source rapid accumulation.The ESR datings show that the alluvial proluvial depos-its were formed in late Early Pleistocene to the middle mid-Pleistocene with multi-stage activities.Combined with the previous studies on the alluvial and pluvial fan deposits,it is inferred that the water systems from the peripheral mountains could formed generally the alluvial and pluvial fan deposits during the filling evolution of Jianghan-Dongting Basin,and that their depositions lasted from early Pleistocene to middle Mid-Pleisto-cene.

关 键 词：更新世 ESR年龄 冲洪积物 鄂东南咸宁地区 江汉-洞庭盆地 

分 类 号：P534.63[天文地球—第四纪地质学]