南京地区雨花台砾石层研究进展与展望  

Advances and prospects on the Yuhuatai gravel layer near Nanjing

作　　者：张玉芬[1] 李长安[2,3] 邵磊[3] 康春国[1] 周耀[1] 

机构地区：[1]中国地质大学(武汉)地球物理与空间信息学院,湖北武汉430074 [2]中国地质大学(武汉)生物地质与环境地质教育部重点实验室,湖北武汉430074 [3]中国地质大学(武汉)地球科学学院,湖北武汉430074

出　　处：《地学前缘》2012年第4期284-290,共7页Earth Science Frontiers

基　　金：国家自然科学基金项目(40771213;40971008)

摘　　要："雨花台砾石层"是长江中下游地区晚新生代地层的重要组成部分,是长江下游新构造运动、晚新生代地质环境变迁和长江形成、演化研究的重要信息载体,一直为地学界所关注。沉积物组成的复杂性和空间分布不连续等特点,使之在地层层序划分、年代地层序列、沉积环境以及与长江的关系等方面长期存在争议。根据野外调查,笔者认为雨花台砾石层是由多时代、多期次、多物源等沉积物相互交切和叠置而构成的复杂堆积体。建议在基础地质调查的基础上,开展系统的地貌学、岩石学、沉积学、古生物学、年代学等综合研究。通过岩石地层学、地貌地层学、生物地层学和年代地层学等的综合分析对比,建立雨花台砾石层的地层层序序列。利用玄武岩与砂砾层互层的特点,重点开展各个玄武岩夹层的40Ar-39Ar法、K-Ar法及古地磁年代测定,辅以砾石层的宇生核素和ESR(电子自旋共振)测年,建立年代地层序列。在地层划分和沉积环境分析的基础上,重点进行砂砾层的物性研究和物源示踪分析,包括:重矿物组合示踪、环境(岩石)磁学示踪、特征岩石矿物示踪(如玛瑙石的物质成分、玄武岩砾石等)等。与长江中、下游同期砾石层(武汉阳逻砾石层,江西九江砾石层,安徽安庆砾石层、铜陵砾石层等)的研究进行对比,借此查明雨花台砾石层与长江的关系,并结合年代地层序列分析长江南京段的形成时代与演化历史。Yuhuatai gravel layer is an important component of late Cenozoic strata in the middle and lower reaches of Yangtze River.As a significant record of information of neotectonics,changes of late Cenozoic geological environment,and evolution of the Yangtze River,the Yuhuatai gravel layer has been highlighted for a long time.Because of the discontinuous spatial distribution and complicated composition of the sediments the division of stratigraphic and chronostratigraphic sequence,sedimentary environment and its relationship with the Yangtze River are still controversial.On the basis of field investigation,we propose that the Yuhuatai gravel layer is composed of multi-age,multi-stage and multi-source sediments.Therefore,it is suggested that systematic and comprehensive researches on geomorphology,petrology,sedimentology,paleontology,geochemistry and geochronology should be carried out.Through comprehensive analysis and comparison of lithostratigraphy,geomorphology stratigraphy,biostratigraphy and chronostratigraphy,we can establish stratigraphic sequence of Yuhuatai gravel layer.The 40 Ar/39 Ar,K-Ar dating methods,and paleo-magnetostratigraphy of all basalt layers with interbeded gravel layers should be conducted in association with cosmogenic nuclide dating and ESR（Electron Spin Resonance） dating method in order to establish the chronostratigraphy of the study area.On the basis of the stratigraphy of the gravel layer,the sedimentology and sedimentary environment analysis on sediments of different stage,the characteristics of the gravel layer should be studied,and series of source-tracing methods,including heavy mineral analysis,environmental（rock） magnetism analysis and characteristic minerals and rocks such as agate and basalt should be carried out.The characteristics of the Yuhuatai gravel layer should be compared with the gravel layers distributed at middle and lower Yangtze River,such as the Yangluo gravel layer in Wuhan,Jiujiang gravel layer in Jiangxi,Anqing gravel layer in Anhui,Tongling gravel layer an

关 键 词：南京 雨花台砾石层 年代地层学 环境意义 

分 类 号：P539[天文地球—古生物学与地层学] X14[天文地球—地质学]