珠江水系演化与东亚地形倒转的耦合关系

新生代以来,全球地质演化中最大的地质事件不外乎青藏高原的形成及其环境效应,其中东亚地区的黄土堆积及大型水系的形成最为瞩目.珠江作为串联华南大陆与南海北部“源-汇”系统的纽带,是南海沉积学研究的焦点,揭示其形成过程对探讨云贵高原以及青藏东南侧的地形演变具有重要意义.采用元素地球化学与碎屑锆石U-Pb年龄谱系源汇综合示踪技术,结合珠江流域及珠江三角洲的研究成果,详细探讨珠江的诞生与演化历史.珠江河流体系初始形成于早渐新世,流域范围仅限于华南沿海地区;晚渐新世珠江发生向西拓展事件,流域面积显著扩大,达到云贵高原东侧边缘;到中新世珠江流域发生明显改变,河流进一步向西、向北溯源侵蚀,流域面积急剧扩大,深入云贵高原腹地.23 Ma珠江流域面积的快速扩展与同时期长江三峡贯通、北方黄土发育均是该时期青藏高原大范围隆升的直接产物,是东亚地区基本形成西高东低地貌特征的具体反映.      

南海北部盆地新生代物源对周边主要河流演化的响应

源汇系统（Source- to- sink system）是将物源区的构造剥蚀、沉积物输送区的沉积物搬运和沉积区的沉积物堆积等视为一个完整系统。沉积物的源区恢复和附近水系重建是源汇研究的热点问题，沉积物碎屑锆石U- Pb定年是源汇系统研究的有效方法之一。南海北部与其周边地区构成了一个完整的源汇系统，通过源汇分析可获得南海北部各盆地沉积物来源及周边主要河流的演化历史。本文通过总结前人在南海北部主要盆地新生代沉积物碎屑锆石U- Pb研究成果，探讨珠江、红河和昆莺琼古河的新生代演化历史。珠江最早的支流北江和东江形成于早渐新世，晚渐新世溯源到西江上游的红水河、左江和右江，中新世溯源到西江中游柳江、桂江和上游的北盘江、南盘江。在晚白垩世—古近纪红河属于青藏高原东缘大型向东南或向南流河流的一部分，之后由于地貌变化形成现今红河。昆莺琼古河在早渐新世开始发育影响到珠江口盆地，在晚渐新世昆莺琼古河雏形已经基本形成，中新世起昆莺琼古河可能向西有一定程度的退缩。     

试论南中国海盆地新生代板块构造及盆地动力学

南海地处欧亚、印度—澳大利亚和菲律宾海板块的交互带,是西太平洋地区面积最大的边缘海之一,其成因机制和演化过程对探讨特提斯构造域和太平洋构造域相互作用及油气勘探等问题具有重要意义,虽备受关注但仍存争议.综合目前该区及外围已有的大地构造等方面的资料,本文从探讨南海外围的构造格架及中-新生代演化过程入手,分析了南海及外围板块...     

华南洋陆过渡带构造演化:特提斯构造域向太平洋构造域的转换过程与机制

南海北部陆缘位于大华南地块洋陆过渡带南段的关键核心段落,曾处于特提斯洋构造域与（古）太平洋构造域交接地带,是印度洋构造动力系统与太平洋构造动力系统波及的共同地区。然而,以往研究和勘探程度较低,特提斯构造域与太平洋构造域交接转换区域的大地构造背景、过程、机制始终不够明确。基于南海北部陆缘地震剖面,不仅关注该区新生代盆地结构构造,以服务该区油气精准勘探,并且试图以此解剖、揭示该区中生代基底结构特征,进而探索新生代南海海盆打开、扩张、停滞到消亡过程的前生今世。对珠江口盆地地震剖面解析和华南陆缘野外构造研究表明:华南地块洋陆过渡带先后经历了中生代印支期碰撞造山、燕山早期增生造山、燕山晚期压扭造山三个过程;随后进入新生代,又经历了早期北东东—南西西走向正断层主控下的弥散性裂解成盆、中期北东—北北东走向张扭断裂主控下的右行走滑拉分成盆、晚期北西—北西西向张扭断裂主控下的左行走滑拉分成盆三期伸展构造叠加。总体上,该区特提斯洋构造体系向太平洋构造体系的转换过程经历了四个阶段:古特提斯洋构造体系向新特提斯洋构造体系转换、新特提斯洋构造体系向古太平洋构造体系转换、新特提斯洋构造体系向太平洋构造体系转换及古太平洋构造体系向太平洋构造体系的转换。东亚洋陆过渡带的构造转换折射出地球深浅部动力系统驱动“东亚大汇聚”的长期机制,即东南亚环形俯冲驱动体系、太平洋LLSVP和非洲LLSVP的深部动力系统（统称为海底“三极”）的重要性,其中,东南亚环形俯冲驱动体系是地球板块运动的重要动力引擎之一。      

多期走滑拉分盆地的沉积响应:以南海北部珠江口盆地为例

南海北部陆缘位于太平洋和新特提斯两大构造域之间,其形成与演化受到多期多向构造叠加作用,珠江口盆地是南海北部陆缘的重要构造单元.自新生代早期珠琼运动以来,由于太平洋板块向华南大陆俯冲在珠江口盆地形成两期强烈的走滑拉分作用,从而导致早期弥散状地堑与后两期拉分盆地的三层盆地叠合现象.本文在综合珠江口盆地的地质、构造物理和数值...     

珠江口盆地成盆‒成烃‒成藏:代序

珠江口盆地位于太平洋俯冲的东部动力系统、印度?澳大利亚板块与欧亚碰撞或新特提斯洋俯冲的西部动力系统相互作用的中间地带,因此其构造成因及南海海盆打开机制一直存在争论;且构造对南海北部陆缘盆地群的油气成藏有何作用也不甚清晰.本专辑以珠江口盆地为例,特别是以阳江东凹为精细解剖区,结合中国东部新生代盆地的研究成果,展开了以下问...     

Cenozoic tectonic jumping and implications for hydrocarbon accumulation in basins in the East Asia Continental Margin

Tectonic migration is a common geological process of basin formation and evolution. However, little is known about tectonic migration in the western Pacific margins. This paper focuses on the representative Cenozoic basins of East China and its surrounding seas in the western Pacific domain to discuss the phenomenon of tectonic jumping in Cenozoic basins, based on structural data from the Bohai Bay Basin, the South Yellow Sea Basin, the East China Sea Shelf Basin, and the South China Sea Continental Shelf Basin. The western Pacific active continental margin is the eastern margin of a global convergent system involving the Eurasian Plate, the Pacific Plate, and the Indian Plate. Under the combined effects of the India-Eurasia collision and retrogressive or roll-back subduction of the Pacific Plate, the western Pacific active continental margin had a wide basin-arc-trench system which migrated or ‘jumped’ eastward and further oceanward. This migration and jumping is characterized by progressive eastward younging of faulting, sedimentation, and subsidence within the basins. Owing to the tectonic migration, the geological conditions associated with hydrocarbon and gashydrate accumulation in the Cenozoic basins of East China and its adjacent seas also become progressively younger from west to east, showing eastward younging in the generation time of reservoirs, seals, traps, accumulations and preservation of hydrocarbon and gashydrate. Such a spatio-temporal distribution of Cenozoic hydrocarbon and gashydrate is significant for the oil, gas and gashydrate exploration in the East Asian Continental Margin. Finally, this study discusses the mechanism of Cenozoic intrabasinal and interbasinal tectonic migration in terms of interplate, intraplate and underplating processes. The migration or jumping regimes of three separate or interrelated events: (1) tectonism-magmatism, (2) basin formation, and (3) hydrocarbon-gashydrate accumulation are the combined effects of the Late Mesozoic extrusion tectonics, the Cenozoic NW-directed crustal extension, and the regional far-field eastward flow of the western asthenosphere due to the India-Eurasia plate collision, accompanied by eastward jumping and roll-back of subduction zones of the Pacific Plate.     

南海北部古河流演变对欧亚大陆东南缘早新生代古地理再造的启示

欧亚大陆东南缘早新生代古地理演变包含了华南沿海中生代山脉的逐步消减与南海的逐步扩张形成等重大事件。南海北部始新统—下中新统“源-汇”路径研究发现,南海沉积物物源在该时期发生了巨大改变。在始新世和早渐新世,源自南海西部古隆起的“昆—莺—琼”河流系统向南海东部地区输送了大量沉积物,包括珠二坳陷在内的南海北部南侧大部分地区受南海西部物源的控制,仅在珠一坳陷接受来自华南大陆珠江的沉积物;晚渐新世,南海西部物源逐步被北部珠江物源取代;到早中新世,珠江来源沉积物全面越过番禺低凸起进入珠二坳陷,大量来自华南内陆的沉积物被珠江运输至南海盆地,“昆—莺—琼”古河流进一步萎缩,仅在南海西部琼东南盆地分布,并且由西向东沉积物源区昆嵩地块逐渐被海南岛取代。南海西部自晚中新世以来发育的中央峡谷正是该古河流的残余。南海新生代早期“昆—莺—琼”河流系统的发现及珠江演变过程的构建,对于深刻认识该地区新生代早期古地理特征、整个欧亚大陆东南缘的古地貌重建以及盆地的油气勘探均具有重要意义。     

南海中部西区新生代构造演化规律与盆地形成演化动力学机制探讨

本文以现代构造地质与地球动力学理论为指导,利用平衡剖面技术对南海中部西区进行了构造演化特征及演变史的恢复,制作了其上下构造层的构造纲要图,划分了南海中部西区新生代以来经历的三大构造演化阶段:(1)裂陷阶段;(2)坳陷阶段;(3)区域沉降。并指出了其动力学机制:始新世末,印度板块与欧亚板块发生碰撞产生的远距离效应以及渐新世西太平洋板块向东亚大陆边缘产生的俯冲效应是南海中部西区新生代构造演化的主要动力学机制。     

珠江口盆地构造演化旋回及其新生代沉积环境变迁

目前对珠江口盆地中生代以来的演化过程及其与沉积环境演变的响应关系尚缺乏系统性认识.基于珠江口盆地中-新生代岩浆活动、断陷结构样式及其改造、典型构造变形样式、沉积中心的转换等特征的对比分析,将盆地中-新生代的构造演化划分为4个阶段、7个期次：（1）中侏罗世-晚白垩世早期（～170～90 Ma）为古太平洋板块俯冲主控的陆缘岩浆弧-弧前盆地演化阶段;（2）晚白垩世-始新世中期（～90～43 Ma）为太平洋板块俯冲后撤背景下弧后周缘前陆/造山后塌陷-主动裂谷演化阶段;（3）始新世中期-中中新世（～43～10 Ma）为华南挤出-古南海俯冲拖曳主导的被动陆缘演化阶段;（4）晚中新世以来（～10～0 Ma）为菲律宾板块NWW向仰冲主导的挤压张扭演化阶段.～90 Ma、～43 Ma、～10 Ma分别实现了由安第斯型俯冲向西太平洋型俯冲、由主动裂谷向被动陆缘伸展、由被动陆缘伸展向挤压张扭的转换.在此过程中,伴随着古南海和南海的发育-消亡,新生代裂陷期沉积环境由东向西、由南向北逐渐海侵,裂后期由南向北阶段性差异沉降,由陆架浅水向陆坡深水转换,这使得珠一/三、珠二、珠四坳陷的石油地质条件具有显著的分带差异性...     

Denudation History of South China Block and Sediment Supply to Northern Margin of the South China Sea

On the basis of apatite fission track (AFT) analyses,this article aims to provide a quantitative overview of Cenozoic morphotectonic evolution and sediment supply to the northern margin of the South China Sea (SCS).Seventeen granite samples were collected from the coast to the inland of the South China block.Plots of AFT age against sample location with respect to the coastline show a general trend of youngling age away from the coast,which implies more prolonged erosion and sediment contribution at the inland of the South China Sea during post break-up evolution.Two-stage fast erosion process,Early Tertiary and Middle Miocene,is deduced from simulated cooling histories.The first fast cooling and denudation during Early Tertiary are recorded by the samples along the coast (between 70 and 60 Ma) and the inland (between 50 and 30 Mu),respectively.This suggests initial local erosion and deposition in the northern margin of the SCS during Early Tertiary.Fast erosion along the coast ceased since ca.50 Ma,while it had lasted until ca.30 Ma inland,indicating that the erosion was transferred from the local coastal zone initially toward the continental interior with unified subsidence of the northern margin,which resulted in the formation of a south-dipping topography of the continental margin.The thermal stosis in the South China block since ca.30 Mu must det'me the time at which the northern margin became dynamically disconnected from the active rifting and stretching that was taking place to the south.The lower erosion rate is inconsistent with higher sedimentary rate in the Pearl River Mouth basin during Late Oligocene (ca.25 Ma).This indicates that the increased sedimentation in the basin is not due to the erosion of the granite belt of the South China block,but perhaps points to the westward propagation of the paleo-Pearl River drainage related to the uplift of the eastern margin of Tibet plateau and southward jumping of spreading axis of the South China Sea.The socond erosion acceleration rate of the Middle Miocene (ca.14 Ma) cooling could have been linked to the long-distance effect of uplift of the Tibet plateau or due to the enhanced East Asian monsoon.     

中国东部新生代沉积盆地演化

新生代, 中国东部大陆边缘系统总体受到来自印度、澳大利亚、菲律宾和太平洋板块向欧亚板块下部俯冲碰撞的作用, 在大陆边缘形成一系列边缘海盆地和断陷-坳陷盆地, 主要发育松辽、渤海湾、江汉、苏北、东海、珠江口和北部湾等盆地.基于中国东部沉积盆地的中生代构造背景分析和新生代盆地的分布特征, 对其中的7个主要沉积盆地进行了详细的沉积序列和构造演化分析.通过周缘板块和郯庐断裂的构造演化、火山活动、低温热年代学、气候演变等对比分析, 中国东部沉积盆地的演化可划分为3个阶段: 古新世-始新世、渐新世-早中新世和晚中新世-第四纪.      

珠江口盆地恩平凹陷恩平组物源体系分析及未来大洋钻探建议

物源体系分析是沉积盆地特征分析的重要内容，为进一步阐明珠江口盆地恩平凹陷恩平组的沉积特征和物源体系，本文拟利用恩平凹陷的三维地震资料和钻井数据，通过古生物环境分析和锆石U- Pb定年等方法，并借助地震剖面中古沟谷的识别、前积反射结构、地震多属性分析结果和沉积相带平面分布特征，对恩平凹陷恩平组物源体系特征进行综合分析。研究结果表明，恩平组PSQ1～PSQ2时期表现位明显的陆相湖盆特征，物源主要为珠江口盆地内隆起的古生代变质岩和中生代火成岩基底，少量来源于北部华南褶皱带的元古宙变质岩；随着PSQ3时期断层活动逐渐停止，湖平面不断上升，华南褶皱带物源供给能力明显增强，逐渐成为恩平凹陷主要物源。鉴于目前南海北部缺少陆相湖盆地层的完整岩芯剖面，制约了南海北部裂陷期构造- 沉积耦合研究并影响了该地区的油气勘探，建议下一步在南海北部陆相沉积盆地(如珠江口盆地)开展大洋钻探工作，以便获取更连续、时间精度更高，受风化作用影响更小的陆相湖盆地层的完整岩芯剖面。这不仅有利于指导下一步油气勘探，也可通过重建陆相沉积盆地不同地质历史时期的沉积变化过程，为了解古气候状态和预测未来气候变化提供重要依据。     

Research Progress in the Petroleum and Natural Gas Geological Theory of China

The Chinese landmass, as a composite region, consists of multiple small continental blocks, such as Sino-Korea, Yangtze, Tarim, etc., and orogenic belts. Because of its distinctive tectonosedimentary evolution, China’s oil/gas-bearing regions differ remarkably from that elsewhere in the world. For instance, in comparison to the Middle East oil/gas-bearing regions which are characterized by Mesozoic-Cenozoic marine oil/gas-bearing beds, early oil and gas discoveries in China are distributed mainly in Mesozoic-Cenozoic continental sedimentary basins. Generation of oil from terrestrial organic matter, or terrestrial oil generation, and the formation of large oil/gas fields in continental sedimentary basins were previously the major characteristics of petroleum geology of China. However, in the past 20 years, a series of major oil and gas discoveries from marine strata have been made. Marine oil/gas fields in China are mainly distributed in the Tarim, Sichuan, and Ordos basins, which are tectonically stable and covered with Mesozoic-Cenozoic deposits. In these basins, hydrocarbon-bearing strata are of old age and the oil/gas fields are commonly deeply-buried. Cumulatively, 995 oil/gas fields have been found so far, making China the fourth largest oil-producing country and the sixth largest gas-producing country in the world. In terms of petroleum and natural gas geology, theories of hydrocarbon generation from continental strata, such as terrestrial oil generation and coal-generated hydrocarbons, etc., have been established. Significant progress has been made in research on the sequence stratigraphy of continental strata, formation mechanisms of ultra-deep clastic reservoirs, and hydrocarbon accumulation in the continental subtle reservoir. Regarding research on the marine petroleum geology of China, with respect to the major characteristics, such as deeply-buried reservoirs, old strata, and multiple phases of transformation, important advances have been made, in areas such as the multiple-elements of hydrocarbon supply, formation of reservoirs jointly controlled by deposition, tectonic activities, and diagenetic fluid-rock reactions, and oil/gas reservoirs formed through superimposed multi-stage hydrocarbon accumulation. As more and more unconventional hydrocarbon resources are discovered, unconventional oil and gas reservoirs are under study by Chinese petroleum geologists, who endeavor to come up with new discoveries on their formation mechanisms.     

南海沉积物中的黏土矿物:指示东亚季风演化历史?

黏土矿物以其示踪洋流变化和揭示物源区同时期气候变化的能力,近年来在南海沉积古环境研究中的地位日益显现。但是,南海黏土矿物能否用于直接指示东亚季风演化历史的研究仍然颇为争议。本研究认为,南海黏土矿物主要受控于物源区供给和洋流搬运作用,黏土矿物本身不具同时期气候条件特征。以南海北部为例,珠江、台湾和吕宋岛这三个主要物源区无论是冰期还是间冰期都提供相同的黏土矿物组合,这些黏土矿物在输入到南海后分别受到不同洋流的搬运。因此,南海晚第四纪黏土矿物组合用于指示东亚季风演化历史的应用是通过洋流的搬运作用来实现的,在不同海区的应用效果不同。     

Discussion on the dextral movement and its effect in continental China and adjacent areas since Cenozoic

Continental China has moved dextral Eastward since Cenozoic time, driven by the collision of the Indian with the Eurasian plate. Evidence for this comes from landscape evolution, the distribution of earthquake epicenters, Cenozoic sedimentary and volcanic rocks, and the measurement of GPS velocity vectors, the distribution of crustal stress, paleomagnetic data, and deep mantle structure, among others. This movement commenced around 40 Ma, coupled with thickened lithosphere and widespread stress release along strike-slip faults that bound the continental Chinese block. Because of continued Northward subduction of the Indian plate, manifestation of the dextral movement has intensified since 25 Ma. Far-reaching effects include extensive strike-slip movement on the Tan-Lu fault in Eastern China, formation of the Dabie ultrahigh pressure metamorphic terrane, extensive thrust faults in East China, delamination and thickening of the lithosphere of South China, a possible tectonic doubling of the Middle-Lower Yangtze Valley metallogenic belt, and the formation of the Japan, Huanghai (East China), and South China Sea.     

南海中北部陆架-陆坡区新生代构造-沉积演化

南海中北部陆架-陆坡区作为南海地区的一个重要地质构造单元,记录了大陆张裂到海盆扩张的丰富信息。通过对研究区地震剖面的解释,分析了该地区新生代的构造与沉积特征,同时通过平衡剖面恢复工作,建立了新生代演化模型。研究显示南海中北部陆架-陆坡区新生代构造演化可以分为三个阶段：古新世—始新世的裂陷阶段、渐新世—早中新世的裂陷-坳陷过渡阶段以及中中新世以来的坳陷阶段。沉积环境经历了河流-湖泊、浅海和深海的演化过程。南海北部陆缘下NW-SE方向流动的地幔流的存在使得伸展活动具有由北向南发育的机制。同时陆坡区盆地（如白云凹陷）显示出韧性伸展的特征,这与地幔上涌热岩石圈伸展引起的该区域地壳强烈韧性减薄和颈缩变形相关。     

志留纪以来的云开地块

桂南－粤西的云开地块,位于特提斯构造带和环太平洋构造带的交汇处。其变质基底仅出露于两广边境的云开大山地区,但古生代海相沉积盖层分布广泛,甚至跨越北部湾。地块北缘的古生代深水沉积带,也延展到越南东北沿海地区。云开地块的范围,可能西起红河三角洲,东达珠江三角洲。晚古生代时,它可能为地处南纬低纬度海域的碳酸盐台地。古南海于中晚二叠世开始张开,使云开地块北移,与大明山地体碰撞,形成云开北缘的造山带。中晚三叠世,古南海的进一步扩张和桂西－越北的古特提斯向南消减,又形成晚二叠世造山带以北的印支期岩浆弧和磨拉石。也是东古特提斯闭合过程的重要部分。新生代早期南海张开前,古南海北侧的南沙地块可能和云开地块相接,总面积可能超过50万km2,在东南亚地质演化中起重要作用。     

东亚及其大陆边缘新生代构造迁移与盆地演化

构造迁移是盆地发展演化过程中十分普遍的地质现象,但西太平洋地区相关研究程度较低,本文基于近10年来对中国东部海域渤海湾盆地、南黄海盆地、东海陆架盆地和南海盆地等所开展的大量研究工作,并综合前人研究成果,对西太平洋地区中最具有代表性的中国东部及邻近海域的新生代构造迁移特征进行了系统讨论.西太平洋活动大陆边缘位于欧亚、太平洋和印度三大板块的交汇处,占据了全球板块汇聚中心的独特位置,并同时受到印度板块的挤入、太平洋板块的后退式俯冲、台湾造山带的楔入的联合作用,自新生代以来,形成了宽阔的自西向东后退式的沟弧盆体系.中国东部及邻区作为西太平活动大陆边缘的重要组成部分,在这个大地构造背景下,新生代的构造特征总体也表现出自西向东的迁移规律,具体表现在盆地的断裂活动性、沉积作用、断陷的萎缩与消亡等自西向东变新逐步演化,新生代的生、储、盖、圈、运、保六大油气成藏要素也表现出西早东晚、自西向东迁移的特征.这种成藏规律的识别对于中国东部油气、天然气水合物勘探具有非常重要的指导意义.最后,从板缘、板内和板下过程和机制,探讨了盆内和盆间的新生代构造迁移机制,这种构造-岩浆-成盆-成藏等的向洋变新迁移和跃迁是晚中生代以来挤出构造和新生代北西向壳内伸展、印度和欧亚板块碰撞诱发的软流圈向东流动的远程效应及太平洋俯冲带的跃迁式东撤的联合效应.     

Characteristics of Meso-Cenozoic Igneous Complexes in the South Yellow Sea Basin, Lower Yangtze Craton of Eastern China and the Tectonic Setting

The South Yellow Sea Basin is partially surrounded by the East Asian continental Meso-Cenozoic widespread igneous rocks belt. Magnetic anomaly and multi-channel seismic data both reveal the prevalent occurrence of igneous rocks. We preliminarily defined the coupling relation between magnetic anomalies and igneous rock bodies. Some igneous complexes were also recognized by using multi-channel seismic and drilling data. We identified various intrusive and extrusive igneous rock bodies, such as stocks, sills, dikes, laccoliths and volcanic edifice relics through seismic facies analysis. We also forecasted the distribution characteristics of igneous complexes. More than fifty hypabyssal intrusions and volcanic relics were delineated based on the interpretation of magnetic anomaly and dense intersecting multi-channel seismic data. It is an important supplement to regional geology and basin evolution research. Spatial matching relations between igneous rock belts and fractures document that extensional N–E and N–NE-trending deep fractures may be effective pathways for magma intrusion. These fractures formed under the influence of regional extension during the Meso-Cenozoic after the Indosinian movement. Isotopic ages and crosscutting relations between igneous rock bodies and the surrounding bedded sedimentary strata both indicate that igneous activities might have initiated during the Late Jurassic, peaked in the Early Cretaceous, gradually weakened in the Late Cretaceous, and continued until the Miocene. Combined with previous studies, it is considered that the Meso-Cenozoic igneous activities, especially the intensive igneous activity of the Early Cretaceous, are closely associated with the subduction of the Paleo-Pacific Plate.