依据重磁资料在南海及其邻区识别出17条深大断裂和10个重磁异常区.据此并结合其他地质资料，在南海及其邻区划分出7个地质结构不同的构造单元.早白垩世南海地区曾形成过统一的基底，新生代时统一的南海基底发生肢解，这一个肢解过程经历了两个在时空上接踵发生、交叠作用的构造事件.第一个构造事件为巽他地块与华夏古陆之间古南海的萎缩、闭合和地块碰撞；第二个构造事件为南沙地块裂离华夏古陆并向巽他地块增生，且伴随新南海的持续扩张，直至中中新世.区域构造演化控制了南海沉积盆地呈"北三南三、东西两竖"格局分布，进而控制了油气富集区的分布.

中生代末期以来,中国南海区域经历古南海裂开—萎缩、新南海裂开—萎缩两大边缘海旋回,形成了南海北部大陆边缘、新南海洋盆、南沙地块、古南海残余洋盆、古南海南部大陆边缘、南海西部大陆边缘和南海东部大陆边缘等构造单元。由于古、新南海洋盆位置的不同,古南海裂开形成的构造格局在后期受到不同的截切、改造,并且形成新的构造格局。两大旋回构造叠加控制了不同单元的性质及其上叠盆地的类型与油气地质条件。南海北部大陆边缘在两大旋回中均表现为被动大陆边缘特征,但早期旋回的大陆边缘规模大(包括新南海旋回被裂离出去的南沙地块),现今残余的早期旋回仅是其陆内陆相裂谷部分, 与晚期旋回陆缘海陆过渡—海相裂谷区叠加,形成拉张盆地。早期烃源岩以中—深湖相地层为主,晚期烃源岩为海陆过渡相三角洲和海相泥岩;早期旋回烃源岩近岸分布,晚期旋回烃源岩远岸分布;早期主要呈陆生陆储或陆生海储,晚期则呈海生海储。南沙地块早期为古南海北部边缘裂陷盆地,发育海相烃源岩;中期向南飘移数千公里,夹持于古、新洋盆之间,沉积欠补偿;晚期被挤压改造,盆地沉积以早期旋回为主,呈现海生海储。古南海南部大陆边缘在早期为被动大陆边缘,晚期被改造成活动大陆边缘;早期的伸展盆地上叠挤压盆地,早期旋回地层被深埋处于变质状态,晚期旋回地层以大型三角洲群和海相泥岩为主,油气兼生,海生海储。南海西部大陆边缘早期为陆内环境,晚期被改造成转换型大陆边缘,张扭盆地发育,早期发育局限的陆相地层,晚期以海陆过渡三角洲相地层为主,该区域热流值高,以生气为主,发育底辟、潜山、生物礁等油气藏。南海东部大陆边缘正在俯冲,发育增生楔盆地。两期旋回不同的叠加关系,导致不同区域油气潜力差异巨大。古南海南部大陆边缘早期拉张、晚期挤压,盆地规模大,烃源岩丰富,均达到成熟状态,油气资源非常丰富。南海北部、西部裂陷盆地发育两套烃源岩,油气很丰富。南沙地块区早期处于古南海北部被动大陆边缘,晚期挟持于古南海残余洋盆与新南海洋盆之间,遭受区域性挤压,构造圈闭非常发育,油气潜力大。南海目前浅水区构造圈闭和生 物礁勘探程度较高,其他非构造圈闭勘探程度很低;深水区和超深水区已有重要发现,但尚处于勘探早期阶段,南海未来勘探潜力依然可观。

Since Late Mesozoic, the united South China Sea region has experienced at least two tectonic cycles of marginal seas, i.e. the cleavage to convergence of the paleao-South China Sea, and the cleavage to convergence of the neo-South China Sea, which formed a couple of structural units, such as the northern continental margin of the South China Sea, the oceanic basin of the neo-South China Sea, the Nansha block, the residual oceanic basin of the palaeo-South China Sea, the northern continental margin of Borneo, and the western and eastern continental margins of the South China Sea. The tectoic framework developed in the cleavage of the palaeo-South China Sea was afterwards truncated and reworked to form a new tectoic framework because of the difference in locations of the palaeo-South China Sea and the neo-South China Sea. The superimposition of these two cycles controls properties of these different units, types of overlying basins and geological conditions of hydrocarbons. The northern continental margin of the South China Sea was of a passive continental margin in both the cycles though its scale (including the Nansha block parting away during the second cycle) was larger in the first cycle than the present residual part of the first cycle, which, only as an intracontinental rift part, was superimposed by the transitional marine rift developed in the late cycle to form tensional basins. Source rocks of the early cycle dominated by semi-deep lake strata, are distributed offshore and mainly generate oil that accumulate in nonmarine or marine facies, while those of the late cycle, composed of mainly transitional deltaic deposits and marine mudstones, are distributed infralittorally and generate oil that are reservoired in marine facies. The Nansha block used to be a rift basin that developed marine source rocks and was located at the northern continental margin of the South China Sea in the early cycle, afterwards it drifted southward for thousand kiometers and lay between the palaeo- and neo-oceanic basins, remaining in an under compensation status. During the late cycle it was compressed and reworked, its deposits are dominated by marine facies of the early cycle, with occurrences of marine source rocks and reservoirs. The southern continental margin of the palaeo-South China Sea used to be a passive continental margin during the early cycle but was reworked into an active continental margin during the late cycle. Stretched basins formed in the early cycle are superimposed by compressional basins developed in the late cycle, and strata of the early cycle are deeply buried and of metamorphism, while strata deposited in the late cycle consist mainly of large-scale deltas and marine mudstones, with occurrences of both oil and gas in marine facies. The western continental margin of the South China Sea was formed in an intracontinental environment during the early cycle, and then reworked into a transformational continental margin during the late cycle, where tenso-shear basins developed with restricted terrestrial strata deposited in the early cycle and transitional deltaic strata deposited mainly in the late cycle. This area has a high value of heat flow and is apt to generate gas. Oil-gas reservoirs such as diapirs, buried hills and reefs are well developed in this area. Presently the eastern continental margin of the South China Sea is subducting with the development of accretionary wedge basins. The superimposition of the two different cycles leads to a great difference in exploration potential of different areas. The southern continental margin of the palaeo-South China Sea experienced extension and compression in the early and late cycles, respectively, resulting in the formation of large-scale basins, the richness of mature source rocks and enormous resources of hydrocarbons. Two suits of source rocks are well developed in rift basins of the northern and western South China Sea and they have generated an abundance of hydrocarbons. The Nansha block was located at the northern passive margin of the palaeo-South China Sea in the early cycle and restrained between the remnant oceanic basin of the palaeo-South China Sea and the oceanic basin of the neo-South China Sea. It contains well-developed structural straps due to regional compression and shows a great potential in petroleum resources. Presently, the degree of petroleum exploration is high in shallow water areas of the South China Sea, especially for structural traps and organic reefs, with the exception of non-structural traps. However, the petroleum exploration in deepwater and ultra-deepwater areas of the South China Sea remains yet at an infant stage though some significant discoveries have been made. Hence, the exploration potential of the South China Sea is still considerably great in the future.

莺歌海盆地周边新生代区域构造演化综合分析表明，该舅地形成和演化构造应力场分四个阶段：第一阶段，古新世末至早渐新世印支地块快速向南东方向挤出，同时伴随着地块的顺时针旋转运动。第二阶段，晚渐新世至早中新世印支地块向南东挤出运动逐渐减弱，华南地块整体仍然相对稳定。莺歌海盆地处于左旋剪切状态。第三阶段，中、晚中新世随着印度地块逐渐楔入欧亚板块内部，印支半岛的挤出运动进一步减弱。至中中新世末，华南地块整体开始挤出。第四阶段，上新世一第四纪印支地块相对稳定，华南地块挤出运动继续进行，两地块间的相对运动呈右旋剪切运动。莺歌海盆地新生代的构造应力场演化受太平洋板块、印度与欧亚板块之间相互作用控制。其中，印度与欧亚板块碰撞作用所导致的印支地块与华南地块的相对运动，是决定莺歌海盆地新生代构造运动应力场变化的主要因素。

Yinggehai basin is located in the northwest of South China Sea， and formed in the Cenozoic The Cenozoic sedimentary thickness in the basin is more than 15km ，therefore，the structural features related to rifting phase are difficult to reveal by seismic profiling In order to understand its origin an d evolution， we analysed the regional characteristics of the Cenozoic tectonic evolution surrounding Yinggehai basin，an d obtained the Cenozoic tectonic stress field of the basin. The formation and tectonic stress field of Yingehai basin can be divided into four phases.The first phase, from the later Paleocene to the early Oligocene，Indochina block extruded toward southeast fast，with a clockwise rotation movement Yinggehai basin origined in this stage.The second phase， from the later Oligocene to the early Miocene， Indochina block’s southeastward extrusion slowed down gradually. However， South China block was relatively stable and Yinggehai basin was under a left-slip shearing condition.The third phase, during the middle and the later Miocene， with the Indochina block intruding into Eurasia plate gradually，Indochina peninsula’s extrusion slowed down further. At the end of the middle Miocene，South China block began to extrude integrally. The last phase，from the Pliocene to the Quaternary period，Indochina block was relatively stable，South China block’s extrusion continues ，the relative movement of these two blocks is right-slip shearingThe Cenozoic evolution of tectonic stress field of Yinggehai basin is controlled by the interaction between Pacific plate， India plate and Eurasia plate. Most of all， the relative movement between Indochina and South China block resulted from the India-Eurasia collision is the dominate factor of the Cenozoic tectonic stress field controlling the origin an d evolution of Yinggehai basin.

南海边缘海构造旋回包括古南海形成与萎缩及新南海形成与萎缩两个构造旋回，形成中央洋壳、大陆坡和大陆架。古南海扩张前南海具有统一拼合基底“古南海陆块”，古南海白垩纪末—始新世为扩张期，渐新世—第四纪为萎缩期，现今洋壳已基本消减殆尽。新南海古—始新世为陆内裂谷期，渐新世晚期—中中新世为洋壳扩张期，中中新世至今为萎缩期，表现为南北向扩张停滞，菲律宾岛弧向西仰冲，但处于萎缩期早期。上述两个旋回叠加控制了南海区域构造格局的形成。边缘海构造旋回控制了南海各大陆边缘及地块性质。北部大陆边缘为被动大陆边缘；南沙地块具有漂移性质；南部大陆边缘为多期叠加型活动大陆边缘，西部具有转换特征，东部为挤压岛架型大陆边缘。

Inversion of satellite-derived free-air gravity-anomaly data has been used to map crustal thickness and continental lithosphere thinning in the South China Sea. Using this, we determine the ocean-continent transition zone structure, the distal extent of continental crust, and the distribution of oceanic lithosphere and continental fragments in the South China Sea. We construct a set of regional crustal cross-sections, with Moho depth from gravity inversion, spanning the South China Sea from offshore China and Vietnam to offshore Malaysia, Brunei and the Philippines to examine variations in ocean-continent transition structure and ocean-basin width. Our analysis shows a highly asymmetrical conjugate margin structure. The Palawan margin shows a narrow transition from continental to oceanic crust. In contrast, the conjugate northern margin of the South China Sea shows a wide region of thinned continental crust and an isolated block of continental crust (the Macclesfield Bank) separated from the Chinese margin by a failed oceanic rift. The Dangerous Grounds are predicted to be underlain by fragmented blocks of thinned continental crust. We use maps of crustal thickness and continental lithosphere thinning from gravity inversion together with free-air gravity- and magnetic-anomaly data to identify structural trends and to show that rifting and the early seafloor-spreading axis had an ENE-WSW trend while the later seafloor-spreading axis had a NE-SW trend.

南海北部大陆边缘新生代盆地都经历了早第三纪裂谷断陷阶段和晚第三纪裂后沉降阶段,但各盆地性质存在显著差异,可以分成拉分型和伸展型两大类,其中伸展型又可分成断陷型和断坳叠加型两亚类。烃源岩主要有湖相泥岩、海陆过渡相泥岩和海相泥岩。储集层包括海相砂岩、生物礁和陆相砂岩。该区生储盖组合主要包括陆生海储型、陆生陆储型和海生海储型。二级构造带包括隆(凸)起带披覆构造、凹陷陡坡断裂构造带、凹内断裂构造带、凹内底辟构造带、缓坡带以及隆起带生物礁等,各个盆地优势油气二级构造带各具特色。勘探领域包括已证实富生烃凹陷的精细勘探、新区勘探和天然气水合物勘探。南海北部地区油气分布受富生烃凹(洼)陷控制,已证实的富烃凹陷仍有很大潜力,是近期勘探的重点;高温高压地区的天然气勘探、深水区勘探是下一步储量增长的接替区。积极开辟和探索新区、新领域是中国南海地区勘探进一步发展的关键。储层的高温高压、低孔低渗,低阻油层和非烃气的识别,以及特殊地质条件下地球物理资料的采集处理是勘探中存在的主要问题。

All the Cenozoic basins on the continental margin of the northern South China Sea experienced two structural phases:Paleogene rift-fault subsidence and Neogene post-rift subsidence.There exist evident differences among the basins,which can be divided into two types as pull-apart and extensional ones.The later can be further classified into fault-subsidence and fault-sag superimposed subtypes.Their source rocks include lacustrine shale,coastal plain swamp shale and marine shale,and the reservoirs are composed of marine sandstone,bioherm and continental sandstone.Source-reservoir-seal assemblages in this area include three different types,such as continental source-marine reservoir,continental source-continental reservoir and marine sourcemarine reservoir ones.Secondary structures for hydrocarbon potentials in different basins are characterized by drape and bioherm in uplift,faulted zone in the abrupt slope of sags,and faulted zone,diapire zone and gentle slope within sags.Explorations in this area are defined as precision exploration in the proven hydrocarbon-rich sags,frontier exploration and gas hydrate exploration.The precision exploration in the proven hydrocarbon-rich sags aims at new traps,types and layer systems,while the frontier exploration aims at Tertiary and pre-Tertiary basins.Explorations in the northern South China Sea have an enormous potential because hydrocarbon-generative sags control hydrocarbon distributions and the proven hydrocarbon-rich sags are major targets for explorations in the near future.The natural gas exploration in high-temperature and high-pressure formations and the exploration in deepwater areas are succeeding fields to increase the reserve next.It is crucial for the next progress in explorations in the South China Sea to actively open up and explore new areas and fields.Major problems remaining in current explorations are how to identify and deal with high-temperature and high-pressure reservoirs,low-porosity and low-permeability or lowresistivity oil layers as well as to collect and process geophysical data under specific geological conditions.

南海南部海域地处多板块交汇处，演化过程复杂，发育多类型含油气盆地，油气资源丰富，系统分析其演化特征与成藏组合对我国在该区开展油气勘探具有重要意义。从研究区地震、钻井资料入手，结合南海南部油气田地质资料，以区域构造—沉积特征为指导，确定南海南部海域盆地的成因类型及演化过程，论述差异演化背景下南海南部海域主要盆地的油气地质条件与成藏组合。研究发现，可以T50、T70、T100三大不整合面为界将南海南部海域主要盆地划分出4套区域成藏组合，分别为深部组合（古近系）、下部组合（始新统—下渐新统）、中部组合（上渐新统—下中新统）及上部组合（中中新统—上中新统），不同盆地主力成藏组合明显不同。究其原因，受盆地构造演化及其古地理位置控制，南海南部海域主要盆地现今所展现的格局是其发育规模最为优势的盆地原型，而优势盆地原型则决定各盆地的油气地质条件与主力成藏组合。

Southern South China Sea has a complex evolutionary process， where multiple plates converge here， and rich in oil-gas resources. This paper starts with seismic data and drilling data， combined with the geological data of oil and gas fields in the southern South China Sea， guided by regional tectonic and sedimentary characteristics， determines the genetic type and evolution process of the basin in the southern South China Sea， and discusses the differences of oil and gas geological conditions and petroleum play. And it can be divided into four regional petroleum plays by T50， T70 and T100 unconformities for the main basins in the southern South China Sea. They are Pre-Paleogene play， Eocene-Lower Oligocene play， Upper Oligocene-Lower Miocene play and Middle Miocene-Upper Miocene play， which is totally different from others. The reason is that， controlled by basin tectonic evolution and paleogeographic position， the pattern of the main basins in the southern South China Sea is mainly the basin prototype with the most advantageous development scale， and the dominant basin prototype determines the oil and gas geological conditions and the main accumulation assemblages of each basin.

In this study, we develop a 3D thermal model of the South China Sea (SCS) lithosphere through the joint analysis of heat flow, Curie-point depth derived from magnetic anomalies, and shear wave velocity. Results show the Moho temperature is below 250 °C in the oceanic basin but exceeds 350 °C in continental margins. We evaluate potential Moho drilling sites based on temperature, crustal thickness, water depth, and sediment thickness, identifying six favorable zones in the east sub-basin. The thermal lithosphere thickness correlates with tectonic settings in continental areas, while the oceanic lithosphere is thicker than predicted by theoretical models. Global analysis suggests that the slow spreading rate may have also contributed to the thickening of the oceanic lithosphere in the SCS.

对392个地温梯度数据和234个大地热流数据的统计结果显示:南海北部深水区地温梯度为2.94～5.22℃/hm,平均为3.91±0.74℃/hm;大地热流值为24.2～121mW/m²,平均为77.5±14.8mW/m²。南海北部地区现今地温场具"热盆"属性,且深水区比浅水区更"热"。大地热流总体变化趋势为:从陆架到陆坡(从北到南)逐渐增高,且增高趋势与地壳减薄趋势一致,同时,平面上存在显著的局部异常点。新生代岩石圈拉张减薄以及新构造运动引发的岩浆、断裂活动是南海北部深水区具"热盆"特征的根本原因,南北向岩石圈减薄程度控制了大地热流总体变化趋势,新构造运动引发的岩浆与断裂活动则是局部热流异常形成的根本原因。

<p>With the statistic results about a total of 392 geothermal gradient values and 234 heat flow values, the geothermal gradients range from 2.94℃/hm to 5.22℃/hm with an average of 3.91&plusmn;0.74℃/hm, and the heat flow values vary from 24.2 mW/m² to 121 mW/m² with an average of 77.5&plusmn;14.8 mW/m² in the deep-water area of the northern South China Sea. The present geothermal field in the deep-water area of the northern South China Sea is characterized with &quot;hot basin&quot;. The heat flow value increases from continental shelf to continental slope against the trend of the crust thickness, its distribution is also characterized with prominent local anomalies. The &quot;hot basin&quot; in the deep-water area of the northern South China Sea might be a result of the combination of the Cenozoic lithospheric thinning with the magma activities and faulting during the Neotectonic event. The variation trend of heat flow value was controlled by the magnitude of the lithospheric thinning. The magma activities and faulting during the Neotectonic period might be the main factors for the existence of the local anomaly of heat flow value.</p>

本文以海洋地质调查和油气勘探开发中积累的地质和地球物理资料的解释和分析为基础，描述和划分了南海北部被动陆缘地壳岩石圈结构构造单元，由陆向海划分出近端带、细颈化带、远端带和洋陆转换带（OCT，含边缘高地）四个构造单元.从细颈化带到OCT基本处于现今陆架坡折带之外的深水-超深水区的范围，以强烈的地壳薄化和发育大型拆离断层控制的拆离盆地为特征.这些深水-超深水盆地的同裂陷阶段均经历了早期均一断陷、中晚期拆离式断陷的演化过程，受控于南海北部大型拆离断层作用及其所导致的岩石圈临界破裂过程.新的深水-超深水盆地形成机理的认识为南海北部陆缘岩石圈的非瞬时伸展破裂过程的分析提供了新的视角，同时，陆缘深水-超深水盆地具有独特的构造-沉积体系配置和构造-热演化过程，将为科学评价南海北部陆缘深水-超深水盆地油气勘探潜力提供新的思路.

南海大陆边缘盆地由于边界条件的差异，不仅形成了不同类型的陆缘盆地，如离散型、走滑伸展型和伸展挠曲复合型，而且这些盆地构造演化存在明显的非同步性。这些陆缘破裂过程与南海扩张作用过程呈现明显不一致性。研究表明，南海扩张时期南海南、北大陆边缘均形成了一系列裂陷盆地，然而，南海南部、北部大陆边缘盆地裂陷作用结束时间不同，北部大陆边缘盆地裂陷作用结束于23 Ma或21 Ma，而南部大陆边缘盆地裂陷作用结束于15.5 Ma，显然北部大陆边缘盆地裂陷结束时间明显早于南部大陆边缘盆地。南海扩张停止后，南海南、北部陆缘仍表现出明显差异，北部陆缘仍以伸展作用为主，晚中新世以来出现快速沉降幕，而南海南部陆缘则以挤压作用为主，且其挤压时间及强度呈现南早北晚的特点，即南部曾母盆地明显早于南薇西盆地和北康盆地。南海南、北大陆边缘盆地形成演化的差异性，特别是构造转型差异变化，为新生代南海扩张的迁移性提供了有力的佐证，可以推断南海不同期次海盆扩张可能存在向南的突然跃迁。因此，本次研究梳理出的南海不同陆缘盆地张裂伸展的非同步性可为南海洋盆扩张演化过程解释提供新的证据。

Continental marginal basins in southern and northern South China Sea (SCS) show not only distinct tectonic regimes, including divergence, transformextensional and flexuralextensional complex types, but also have different tectonic evolutionary stages, due to different boundary conditions. Discordance between the breakup of continental margins and South China Sea spreading processes are presented. The research results indicate that a series of rifting basins are developed in the southern and northern continental margins during the SCS spreading, which are resulted in the formation of main rifting stage. However, the time of breakup unconformity is quite different. The rifting terminates on the age of 23 Ma or 21 Ma in the northern margins of the SCS, while did not terminate until the age of 15.5 Ma in the southern margins of the SCS. Those features indicate that the age of the breakup unconformity in the continental margins show a clear shift southward, which means that in the northern SCS is earlier than in the southern SCS. There are clear differences in tectonic regimes after the termination of the SCS spreading. Extension is dominated in the northern SCS and rapid subsidence episode is present since the Late Miocene, but compress regimes are present in the southern SCS, where the age and intension of compressive stress in the Zengmu basin are earlier and stronger than in the Beikang and Nanweixi basins. Transformation and distinct tectonic evolution in the southern and northern continental marginal basins indicate the shift of the SCS spreading, and are used to suggest the shift southward in the different ending times of the spreading processes for the three oceanic subbasins of the SCS. Therefore, differences in formation and evolution of continental marginal basins in the northern and southern SCS provide a helpful evidence for the reasonable interpretation for the spreading processes of the SCS.

古潜山是南海西部琼东南盆地深水区重要的油气勘探领域，其中陵南低凸起古潜山领域天然气资源探明程度低，勘探潜力大。为加快陵南低凸起古潜山领域勘探进程，开展烃源条件、储盖组合、输导体系等油气成藏条件的综合评价，同时结合多种地球物理手段预测潜山裂缝型储层，提出后续评价有利目标。结果表明：①陵南低凸起古潜山紧邻乐东—陵水富生烃凹陷，发育新生界厚层海相泥岩盖层与中生界花岗岩潜山储层优势储盖组合，具有大型沟源断裂、潜山内幕断裂、继承性构造脊等组成的复合运移模式以及源储压差大、近源充注的优势，成藏条件优越；②应用似然体、蚂蚁体、曲率体以及属性融合技术，结合区域构造应力场以及主要断层产状，综合预测陵南低凸起潜山裂缝型储层的展布特征，圈定有利勘探区带陵1构造、陵4构造，有助于推动后续勘探评价工作的进行。陵南低凸起古潜山整体油气成藏条件优越，预测多个构造储层发育，规模成藏概率大，是琼东南盆地继中央峡谷水道之外又一深水油气勘探新的有利方向。

The granitic buried-hill is an important oil and gas exploration field in the deep water area of the Qiongdongnan Basin in the western part of the South China Sea， among which the granitic buried-hill area of the Lingnan Low Uplift has a low degree of natural gas resources exploration and great exploration potential. In order to accelerate the exploration process of the buried-hill on the Lingnan Low Uplift， the comprehensive evaluation of hydrocarbon accumulation conditions such as hydrocarbon source conditions， reservoir cap combination， and transmission system was carried out， and a variety of geophysical means were combined to predict the fracture reservoirs in the buried-hill and pointed out favorable targets for subsequent evaluation. The results show that： （1） The buried-hill on the Lingnan Low Uplift， adjacent to the Ledong-Lingshui hydrocarbon-rich sag， developing the coupled reservoir cap assemblage composed of Neogene thick cover of marine mudstone and Mesozoic granite buried-hill reservoir， having the advantages of composite migration mode composed of large source-connected faults， buried-hill insider faults and inherited structural ridges， as well as large source storage pressure difference and near-source charging， has superior storage conditions. （2） The application of likelihood， ant body， curvature body and attribute fusion technology， combined with regional tectonic stress field and main fault production status， comprehensively predict the spread characteristics of the buried-hill fracture reservoirs in the Lingnan Low Uplift， and delineate the favorable exploration area， such as Ling 1 and Ling 4， which is helpful to promote the subsequent exploration and evaluation work. The Lingnan Low Uplift， having excellent hydrocarbon accumulation conditions， which is predicted that there are multiple tectonic zones with reservoir development and high probability of large-scale accumulation， is a new favorable direction for oil and gas exploration in the deep water areas in addition to the Central Canyon of the Qiongdongnan Basin.

琼东南盆地中央峡谷沉积物来源是南海地区沉积学研究中的热点问题。研究采用稀土元素及碎屑锆石年龄等方法，对琼东南盆地中央峡谷上中新统&mdash;上新统以及盆地基底和周边可能源区开展对比分析。研究发现，中央峡谷西侧上中新统&mdash;上新统多数样品呈现出Eu元素正异常，峡谷东侧样品则以Eu元素的负异常为主，并且随着时代变新，呈现Eu元素负异常的样品数量增多；同时，样品中碎屑锆石年龄谱系也呈现规律性变化，峡谷西侧沉积物相对包含的古生代及元古代等古老锆石比峡谷东侧多，峡谷东侧的碎屑锆石年龄则以燕山期和印支期2个中生代年龄峰值为主。结果显示，越南中北部印支期的板块拼合带是中央峡谷的重要物源区，控制着中央峡谷的沉积充填，海南岛是中央峡谷另一重要物源区，其在中央峡谷西侧为次要物源，但是到峡谷东侧则为主要物源区。

<div style="line-height: 150%;">Provenance studies of the Central Canyon，Qiongdongnan Basin provide significant insights into sedimentology research of the South China Sea (SCS).A suite of geochemical approaches mainly including Rare Earth Elemental (REE) analysis and detrital zircon U-Pb dating has been systematically applied to the comparison between our Upper Miocene-Pliocene Central Canyon samples and the Qiongdongnan basement as well as its surrounding potential source areas.The REE patterns indicate that the western Central Canyon is generally characterized by positive Eu anomaly in contrast to the negative Eu anomaly of its eastern side during the Late Miocene-Pliocene period.Additionally，samples bearing negative Eu anomaly have become more dominant within the younger geological strata for the entire canyon.U-Pb chronology results suggest a wide Proterozoic to Mesozoic age range with the complex peak distribution of Yanshanian，Indosinian，Caledonian and Jinningian periods.For most of the western samples，their age signatures are older than the eastern which mainly shows distinguishable peaks of Yanshanian and Indosinian period.Conclusively，our data implies contributions from two important sources：(Ⅰ) the Indosinian collision orogenic belt in central-northern Vietnam affecting the entire Central Canyon;(Ⅱ) the Hainan Island particularly as an eastern provenance area.</div><div style="line-height: 150%;">&nbsp;</div>

古潜山是南海西部琼东南盆地深水区重要的油气勘探领域，其中陵南低凸起古潜山领域天然气资源探明程度低，勘探潜力大。为加快陵南低凸起古潜山领域勘探进程，开展烃源条件、储盖组合、输导体系等油气成藏条件的综合评价，同时结合多种地球物理手段预测潜山裂缝型储层，提出后续评价有利目标。结果表明：①陵南低凸起古潜山紧邻乐东—陵水富生烃凹陷，发育新生界厚层海相泥岩盖层与中生界花岗岩潜山储层优势储盖组合，具有大型沟源断裂、潜山内幕断裂、继承性构造脊等组成的复合运移模式以及源储压差大、近源充注的优势，成藏条件优越；②应用似然体、蚂蚁体、曲率体以及属性融合技术，结合区域构造应力场以及主要断层产状，综合预测陵南低凸起潜山裂缝型储层的展布特征，圈定有利勘探区带陵1构造、陵4构造，有助于推动后续勘探评价工作的进行。陵南低凸起古潜山整体油气成藏条件优越，预测多个构造储层发育，规模成藏概率大，是琼东南盆地继中央峡谷水道之外又一深水油气勘探新的有利方向。

The granitic buried-hill is an important oil and gas exploration field in the deep water area of the Qiongdongnan Basin in the western part of the South China Sea， among which the granitic buried-hill area of the Lingnan Low Uplift has a low degree of natural gas resources exploration and great exploration potential. In order to accelerate the exploration process of the buried-hill on the Lingnan Low Uplift， the comprehensive evaluation of hydrocarbon accumulation conditions such as hydrocarbon source conditions， reservoir cap combination， and transmission system was carried out， and a variety of geophysical means were combined to predict the fracture reservoirs in the buried-hill and pointed out favorable targets for subsequent evaluation. The results show that： （1） The buried-hill on the Lingnan Low Uplift， adjacent to the Ledong-Lingshui hydrocarbon-rich sag， developing the coupled reservoir cap assemblage composed of Neogene thick cover of marine mudstone and Mesozoic granite buried-hill reservoir， having the advantages of composite migration mode composed of large source-connected faults， buried-hill insider faults and inherited structural ridges， as well as large source storage pressure difference and near-source charging， has superior storage conditions. （2） The application of likelihood， ant body， curvature body and attribute fusion technology， combined with regional tectonic stress field and main fault production status， comprehensively predict the spread characteristics of the buried-hill fracture reservoirs in the Lingnan Low Uplift， and delineate the favorable exploration area， such as Ling 1 and Ling 4， which is helpful to promote the subsequent exploration and evaluation work. The Lingnan Low Uplift， having excellent hydrocarbon accumulation conditions， which is predicted that there are multiple tectonic zones with reservoir development and high probability of large-scale accumulation， is a new favorable direction for oil and gas exploration in the deep water areas in addition to the Central Canyon of the Qiongdongnan Basin.

The Qiongdongnan Basin, situated in the west part of northern South China Sea, is one of the important deepwater exploration prospects in China. This basin has tectonic-sedimentary characteristics and petroleum geology conditions different from other typical deepwater basins around the world. Initially, the cooperative exploration in this basin was carried out in a slow progress. Through continuous efforts and independent innovations, CNOOC Limited (&ldquo;CNOOC&rdquo;) has made great breakthroughs during the 12th Five-Year Plan by addressing the bottlenecks in relation to basin formation, hydrocarbon generation and accumulation, etc. During this period, CNOOC discovered the giant Central Canyon gas field consisting of several large-medium gas fields. Natural gas is mainly enriched in turbidite channel sandstones of the Huangliu Formation in the lower section of the canyon, and also in submarine fans of the Yinggehai Formation in the upper section. According to this study, hydrocarbon accumulation of this giant gas field attributes to following conditions: (1) the marine-terrestrial and marine source rocks of the Yacheng Formation serve as the major gas source rocks; (2) the turbidite channel sand and large-scale submarine fan reservoirs are shallowly buried, with favorable physical properties; (3) turbidite sandstones developed in multi stages constitute a large group of lithologic traps; (4) microfaults and fissures vertically connect deep source rocks and shallow traps; and (5) thick bathyal mudstone cap rock developed in late stage has good preservation conditions. In general, the natural gas reservoirs are characterized by &ldquo;multiple reservoirs independently existing and vertically overlapped&rdquo;, and controlled by structural-lithologic traps. There are still more prospects in the Central Canyon, suggesting huge exploration potential.

南沙海域主要盆地含油气系统及其成藏要素受构造演化阶段控制和影响，表现为不同类型盆地的充填却具有类似的特点，即同期地层沉积特征相似且起分隔作用的不整合年龄相当。主要盆地经历了古近纪&mdash;早中新世裂谷期和中中新世以来的后裂谷期构造发展阶段，发育4种各具特色的含油气系统：(1)万安盆地西部发育裂谷早期湖相含油气系统；(2)万安盆地东部、曾母盆地巴林坚地区、礼乐盆地和西北巴拉望盆地发育裂谷晚期海侵三角洲含油气系统；(3)曾母盆地中、西卢卡尼亚和东纳土纳发育后裂谷早期海相含油气系统；(4)文莱沙巴盆地发育后裂谷晚期海退三角洲含油气系统。烃源岩以中新统泥岩为主；煤系仅对气有贡献；其中海陆过渡相烃源岩占主导地位；海相烃源岩对油的贡献约占一半；陆相烃源岩贡献微弱。储层以上中新统砂岩、中&mdash;上中新统灰岩为主；前者聚油，后者聚气。聚油圈闭以构造为主，其次是地层构造圈闭；聚气圈闭则依次为地层、地层构造和构造；基岩圈闭常为前裂谷期的裂缝性火成岩或变质岩。

在广泛调研国内外相关文献的基础上，利用地震资料最新重处理和解释成果，结合最新收集的国外地质研究资料，系统总结分析了北康盆地构造演化特征、沉积特征、油气地质条件。研究认为盆地总体上经历了断陷期、坳陷期和区域沉降期三大构造演化阶段，主要发育三角洲相、滨浅海相、半深海-深海相，局部古隆起地区发育碳酸盐台地。北康盆地普遍发育中始新统、上始新统-下渐新统和上渐新统-下中新统3 套烃源岩；油气储层主要有古近系砂岩、中中新统石灰岩/ 礁灰岩两大类；上新统-第四系泥质岩层为区域性盖层。北康盆地油气资源潜力巨大，石油地质资源量为8.86&times;10⁸t，天然气地质资源量为14855&times;10⁸m³。

Based on the extensive investigation of related literatures in China and abroad, the latest seismic data reprocessing and interpretation results, and the latest collections of foreign geological studies, systemic summarization and analysis were completed on the tectonic evolution, sedimentary characteristics, and petroleum geological conditions in the Beikang Basin. The results show that the Beikang Basin generally experienced three tectonic evolution stages, i.e. fault depression, depression and regional subsidence, giving rise to delta facies, littoral neritic facies, and bathyal-abyssal facies, or carbonate platform in local paleo-uplifts. Three sets of source rocks are developed in the Middle Eocene, the Upper Eocene-Lower Oligocene, and the Upper Oligocene-Lower Miocene, respectively. Oil and gas reservoirs have been identified within the Paleogene sandstone and the Middle Miocene limestone/reef limestone. The Pliocene-Quaternary mudstone acts as the regional caprock. In conclusion, the Beikang Basin has huge potentials of oil and gas resources, with geological resources of oil and gas of 8.86&times;10⁸t and 14855&times;10⁸m³, respectively.

南海西缘中建南盆地勘探程度低，制约了油气勘探进展。通过全面整合中建南盆地各时期二维地震资料和油气勘探成果，对中新统—始新统地层发育特征和盆地构造格局进行了系统分析，并探讨了油气地质条件和成藏模式。研究结果表明：①中建南盆地主要发育5个区域不整合，分别为始新统底界、中新统三亚组底界、日照组底界、重云组底界和上新统中建组底界。伸展断裂和走滑断裂主要呈近SN、NE和NW向展布，其中近SN向和NE向断裂控制了盆地隆坳格局，可以划分出“三坳两隆一斜坡”等6个一级构造单元。②中建南盆地发育中始新统湖相烃源岩、上始新统—渐新统湖相和海陆交互相烃源岩以及下—中中新统海相烃源岩等3套主力烃源岩，油气沿构造脊和大型不整合面侧向运移，沿大型油源断裂垂向输导，上新统—第四系区域泥岩盖层披覆下的构造、地层和岩性等多种圈闭是油气聚集成藏的有利场所；西部斜坡、北部隆起及南部隆起的构造与地层圈闭，北部和中部坳陷的岩性圈闭群，以及西部斜坡和中部隆起等局部构造高部位发育的生物礁储层等都具备一定的勘探潜力。

The low exploration level of Zhongjiannan Basin in the western edge of the South China Sea has constrained the progress of hydrocarbon exploration. By integrating 2D seismic data and exploration achivement from different periods in Zhongjiannan Basin, stratigraphic development characteristics and structural patterns of Miocene to Eocene were systematically analyzed, and geological conditions and hydrocarbon accumulation mo-dels were explored. The results show that： （1） Five major regional unconformities, such as the bottom boundary of Eocene, the bottom boundary of Miocene Sanya Foumation, Rizhao Formation bottom boundary, Chongyun Formation bottom boundary, and the bottom boundary of Pliocene Zhongjian Formation, are developed in Zhongjiannan Basin. Extensional and strike-slip faults are mainly distributed in the near SN, NE, and NW directions. And the near SN and NE-trending faults control the pattern of uplifts and depressions in the basin. Upon that, Zhongjiannan Basin can be divided into six first-order structural units of “three depressions, two uplifts, and one slope”. （2） There are three main sets of hydrocarbon source rocks developed in Zhongjiannan Basin, including middle Eocene lacustrine source rocks, Upper Eocene-Oligocene lacustrine and marine-terrestrial source rocks, and Lower-Middle Miocene marine source rocks. Hydrocarbon migrate laterally along structural ridges and large-scale unconformities, and transport vertically along major oil-source faults. Structures, strata, and lithology under the regional mudstone cover of Upper Neogene and Quaternary are favorable places for hydrocarbon enrichment and accumulation. The structural and stratigraphic traps of the western slope, northern uplift, and southern uplift, lithological trap groups of the northern and central depressions, as well as reef reservoirs developed in the high parts of local structures of the western slope and central uplift, all have certain exploration potential.