摘要
长江的形成标志着中国地貌格局的形成与东亚现代地貌格局的建立。文中简述了百余年间长江演化研究的主要争论,梳理了近20年来将物源示踪方法应用于长江演化研究的进展及得到的启示。通过对长江流域的典型沉积体系:包括上游昔格达组、剑川盆地、中下游砾石层、江汉盆地、长江三角洲钻孔沉积及边缘海盆地(莺歌海盆地、中国台湾岛)的物源示踪结果进行归纳梳理,笔者认为:1)长江演化争论的焦点问题依旧是三峡贯通和石鼓第一弯的形成,但争论的问题已拓宽至古水系模式、侵蚀-沉积过程、夷平面形成等诸多问题。2)三峡贯通和石鼓第一弯形成的时代尚未取得共识,即长江的形成时代和过程还存在争论。长江中下游砾石层和江汉盆地沉积物具有复杂的源区供应,仅依靠碎屑锆石U-Pb年代学无法有效区分长江上游的物源信号;江汉盆地和长江三角洲钻孔沉积记录对于三峡贯通的初始信号仍未达成一致;剑川盆地和昔格达组沉积物的年代及其物源意义对于金沙江南流(东流)的指示意义存在广泛争论;海洋沉积约束长江和红河水系演化模式的物源信号也存在争议。3)在长江流域各沉积盆地进行物源研究时,建议加强海陆沉积对比。从地貌-构造演化-沉积古地理-气候变迁的角度,将能更加全面地重建长江演化的历史。
The evolution history of the great rivers is one of the most important subjects in earth science,especially,the capture events and changes of great rivers which originate from the inner area of the Qinghai-Tibetan plateau and flow into the ocean are hot problems for geomorphology and geology.The Yangtze River is a representative river link with the Qinghai-Tibetan plateau and the Pacific Ocean,formation of the Yangtze River is considered an important mark ofthe Chinese landscape formation and the establishment of the modern geomorphic pattern of the East Asia.The evolution of the Yangtze River is closely linked to the uplift of the Qinghai-Tibetan plateau and the birth of the margin seas and monsoon evolution.In this study,we concluded the main debates on the evolution of the Yangtze River for more than one century,and the progresses of provenance analysis applied to the continental and sea basins of the Yangtze River in the past two decades.We collected the provenance analysis results from typical sedimentary depositions in the Yangtze River catchment,including the Xigeda Formation in the Panzhihua-Xichang area of the upper reaches,Cenozoic sedimentary of the Jianchuan Basin which is near the First Bend of Shigu,Gravel Layers in the middle and lower reaches,borehole sediment of the Jianghan Basin and Yangtze River Delta,and sediment of the marginal sea basins(Yinggehai Basin,Taiwan Island).We conclude that:1)the debates on the evolution of the Yangtze River are still focused on two questions:when the Three Gorges was formed and whether south flowed off the palaeo-Jinsha River in the First Bend of the Shigu,but the debates have extended to the palaeo-drainage model in East Asia during the Cenozoic period,geomorphic formation history and exhumation-deposition process of the SE Tibet,high elevation-low relief surface formation in the SE margin of the Tibet and many important issues.2)There is no consensus regarding the formation time and process of the Three Gorges and the First Bend,the formation time,process,and mechanism of the Yangtze River are still vigorously debated.There are mainly two views on the Miocene and early-middle Pleistocene for the formation time of the Yangtze River and mainly three paleo models of the upper Yangtze,south flow,east flow,and southeast flow.The provenance of gravel layers in the middle and lower reaches of the Yangtze River and boreholes sediment in the Jianghan Basin have complex source regions.Because of the extreme stability and multiple recycle of the detrital zircons,it is difficult to distinguish the provenance signals of the upper reaches of the Yangtze River effectively from the modern and Cenozoic sediment in basins based on the detrital zircon U-Pb age,whether the“Yangtze Gravel at Nanjin”represents the age of the Yangtze River is still strongly debated.There is still no agreement on the initial signal of the sediment of the upper Yangtze River from the boreholes record in the Jianghan Basin and the Yangtze River Delta.The boreholes deposition age is also controversial.The provenance implications of the Cenozoic sediment of the Jianchuan Basin and the Xigeda Formation for the south flow(east flow)of the Jinsha River are widely debated.The marginal sea sediment provenance signals that constrain the evolution model between the Yangtze and the Red River are also controversial.3)There is a big difference between the drainage catchment of the paleo-Yangtze and modern Yangtze,in the provenance analysis of the sedimentary basins of the Yangtze River,suggesting constrain provenance area by multi-mineral and multi-index and strengthen the comparison between the continental and marginal sea basins.The evolution history of the Yangtze River will be reconstructed more comprehensively from the perspective of geomorphology,tectonic evolution,sedimentary paleogeography and climate change.
作者
郭汝军
魏传义
李长安
张玉芬
李亚伟
孙习林
张增杰
冷勇辉
苏建超
李国鼐
吕凌云
陈旭
丁智强
GUO Ru-jun;WEI Chuan-yi;LI Chang-an;ZHANG Yu-fen;LI Ya-wei;SUN Xi-lin;ZHANG Zeng-jie;LENG Yong-hui;SU Jian-chao;LI Guo-nai;Lü Ling-yun;CHEN Xu;DING Zhi-qiang(School of Geography and Information Engineering,China University of Geosciences,Wuhan 430074,China;State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029,China;Hubei Key Laboratory of Critical Zone Evolution,China University of Geosciences,Wuhan 430074,China;Institute of Geophysics and Geomatics,China University of Geosciences,Wuhan 430074,China;College of Tourism and Planning,Pingdingshan University,Pingdingshan 467000,China;Faculty of Resources and Environment Science,Hubei University,Wuhan 430062,China;School of Earth Science and Engineering,Sun Yat-Sen University,Guangzhou 510275,China;School of Tourism and Geographical Sciences,Yunnan Normal University,Kunming 650500,China)
出处
《地震地质》
EI
CSCD
北大核心
2023年第1期1-28,共28页
Seismology and Geology
基金
国家自然科学基金(41671011,42171008,42002203)资助。
关键词
长江演化
争论与进展
物源示踪
长江三峡
长江第一弯
Yangtze River evolution
debates and progresses
provenance analysis
Three Gorges
First Bend