塔北隆起西部东河塘油气来源及分布

东河塘油田位于塔北隆起西部，其周缘多个构造带均获得油气，是一个重要的富油气区带，泥盆系东河砂岩和侏罗系地层是两套最为重要的储集层。原油主要来自于中、上奥陶统海相烃源岩，晚海西期和晚喜山期是两个重要的充注期，其中早期形成的油气藏普遍遭受降解破坏，现今发现的正常原油以晚期注入为主。侏罗系还包括晚喜山期库车坳陷生成的陆相油气的注入，白垩系卡普沙良群之下的不整合面是重要的油气运移通道，与之相接触的层位均有机会捕获陆相油气。综合油气地球化学特征与及横向、纵向地质对比，东河砂岩深部的奥陶系、志留系可成为潜在的勘探目的层，而东河塘地区侏罗系陆相油气的存在，进一步拓宽了塔北隆起陆相油气的勘探领域。

Advances and prospects on the Yuhuatai gravel layer near Nanjing

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 and so on.All of these can help us to identify the relationship between Yuhuatai gravel layer and Yangtze River.With the chronostratigraphy sequence analysis,the formation time of the Yangtze River at Nanjing can be figured out.