川南下志留统石牛栏组沉积体系与岩相古地理

四川盆地南部下志留统石牛栏组为在缓坡陆棚基础上发育起来的碳酸盐台地的沉积,可划分出4个岩性段和2个沉积旋回.沉积体系在空间展布特征上表现为由南向北的从碎屑滨岸→局限台地→开阔台地→生物礁/滩→台地边缘斜坡→浅水陆棚浅滩→泥质浅水陆棚→深水陆棚变化,在垂向上则由泥/灰质深水→浅水陆棚→碳酸盐台地的变化;海平面变化是控制沉积体系发育和空间分布的重要因素.     

南盘江地区晚二迭世沉积环境模式及构造控制

据晚二迭世沉积相展布和各相带特征分析,南盘江地区晚二迭世可分为大陆、滨海·亚浅海和浅到半深海沉积区,相应地发育了两种类型的碳酸盐台地,台地边缘生物礁和深水海槽相沉积。沉积海盆的上述特性,同区域板块构造发展史有关,并直接受区内古断裂活动的控制。从本区的构造活动性提出了石油勘探中值得注意的问题。     

碳酸盐台地高水位溢流沉积研究

碳酸盐台地高水位溢流是指在海平面高水位期,台地沉积物被搬运到斜坡及较深水盆地中沉积下来所形成的沉积体。一般发育在镶边陆架型台地或平顶台地低纬度暖水区,它的形成受台地类型、台地斜坡坡度、海平面变化幅度等要素的制约。     

四川盆地二叠纪-三叠纪开江-梁平陆棚形成演化与礁滩发育

四川盆地北部开江-梁平陆棚的形成与峨眉"地裂运动"有关。通过对野外露头、钻探资料及地震资料系统分析,其发展和消亡过程对区内上二叠统吴家坪组-下三叠统飞仙关组沉积相的演化有着明显的控制作用,决定了生物礁和鲕粒滩的分布,从而也决定了礁、滩气藏的类型、规模及分布。上二叠统吴家坪组为碳酸盐岩缓坡沉积,至长兴期,受拉张作用进一步加剧影响,陆棚相区进一步下沉,陆棚边缘的生物礁及高能滩集中快速生长,沉积模式由碳酸盐缓坡演化为镶边台地沉积。随着台地的不断增生,鲕粒滩分布区不断向东往陆棚一侧迁移,发育层位从台地向陆棚亦逐渐抬升,开江-梁平陆棚逐渐萎缩并最终消亡。     

新生代早期南海北部水系演变

珠江在早渐新世仅是涉及华南沿海地区的小河;到晚渐新世,向西延伸到云贵高原前缘地带;到中新世,现代珠江流域格局初步形成。证据显示,南海北部还发育过一条源自南海西部隆起区的大型水系-昆莺琼古河,后淹没在南海之中,但在南海的沉积充填过程中扮演了重要角色。南海北部水系及沉积环境的重建,对于深刻认识南海新生代早期古地理特征以及该地区的油气勘探均具有重要意义。     

珠江口盆地(东部)新近系珠江组碳酸盐台地沉积特征及其地震相特征

利用钻井、测井及地震资料,通过对珠江口盆地(东部)大量的岩心和薄片的观察鉴定以及对地震剖面资料的精细解释,进而探讨珠江组碳酸盐台地的沉积特征与地震响应特征.珠江口盆地(东部)碳酸盐岩由于古地貌及海侵时间的差异性,珠江组沉积序列,特别是碳酸盐台地的沉积厚度及发育时间,存在明显的差异性.碳酸盐台地沉积相带发育齐全,包括:开阔台地、台地边缘及其台地前缘斜坡3类沉积相.碳酸盐台地的地震相特征突出,易于识别.     

六盘山地区早中奥陶世碳酸盐台地-斜坡沉积特征及沉积环境分析

六盘山地区早中奥陶世马家沟组、平凉组为一套碳酸盐台地-斜坡沉积建造序列,发育碳酸盐开阔台地沉积体系、台地灰泥、碎屑流沉积体系及重力滑塌、碳酸盐浊流等沉积体系。自下而上为一套向上变粗变厚的进积型沉积建造。反映了鄂尔多斯陆块西缘早中奥陶世被动大陆边缘碳酸盐陆棚与台前海盆共存的古地理格局。     

新生代南海北部碳酸盐岩台地的淹没事件研究

碳酸盐岩台地广泛发育及其淹没事件是南海新生代地层的重要特征之一。通过钻孔揭示的地层，古生物等资料对位于南海北部的东沙和西沙碳酸盐岩石地发育，演化及其淹没层序进行了分析，首次提出了本区自新生代以来经历了三次大的淹没和若干次小的淹没事件，分别相当于Haq提出的三级和四级层序。     

桂西北隆或石炭系沉积相—一个孤立的古碳酸盐台地剖析

本文剖析了滇黔桂南盘江地区晚古生代一系列古碳酸盐台地中的一个小型台地—桂西北隆或台地。隆或地区石炭系沉积相可分为台地、台缘斜坡及海槽三大类型。根据沉积相的空间展布,隆或古台地在石炭纪时为一个孤立的碳酸盐台地,周围被海槽围限。古断裂活动造成了槽台相间的古地貌格局,也是碳酸盐台地演化的古构造背景。     

东北地区晚泥盆世岩相古地理研究

利用野外实测剖面和区域地质资料,在地层划分和对比、构造格局研究以及早中泥盆世研究基础上,从点—线—面的沉积相分析入手,将晚泥盆世的弗拉斯期和法门期作为一个编图单元进行岩相古地理编图,恢复了东北地区晚泥盆世的岩相古地理面貌。研究表明,晚泥盆世东北地区主要发育浅海陆棚沉积体系(浅海陆棚相)、无障壁海岸沉积体系(滨海相)、三角洲沉积体系(三角洲相)、碳酸盐台地沉积体系(局限台地、开阔台地相、台缘斜坡相)和障壁海岸沉积体系(潟湖、潮坪相);存在额尔古纳和松辽两个主要古陆区,其余地区以滨、浅海相沉积为主。黑龙江小河里河、内蒙古卧都河地区发育三角洲相沉积;苏尼特左旗西南部受到海侵影响,海侵方向由西向东,发育滨海相沉积;沿贺根山-扎兰屯一线仍为陆间洋盆俯冲形成的蛇绿混杂岩带。     

南海珠江深水扇系统的沉积构造背景分析

从深水扇系统的观点出发,主要基于对最近所采集的穿越整个白云凹陷的700余公里长电缆深反射(深达14 s)地震资料综合解释,结合南海大洋钻探的成果,对南海珠江深水扇系统沉积的构造背景特征进行了综合分析.研究发现:白云主凹在早中新世-中中新世期间(即大约距今25～10 Ma)是一个因坳陷期盆地基底的持续沉降及其相关断裂活动而形成的南海北部陆缘上的斜坡内盆地;白云主凹这个"斜坡内盆地"有别于世界上其它位于被动大陆边缘背景中(如西非近海、巴西近海、墨西哥湾)的斜坡内盆地;海平面变化、沉积物通量变化、构造活动等地质营力都在斜坡内盆地的构造背景上对南海珠江深水扇系统在不同时期产生了不同程度的重要影响.简言之,斜坡内盆地成就了南海珠江深水扇系统.这为以后进一步全面深入研究南海珠江深水扇系统的形成机制、演化过程、结构特征等有着重要意义.     

南海北部陆坡地形特征及其影响因素研究

南海北部陆坡位于南海北部大陆边缘,地质构造活动丰富,是大陆和深海进行物质和能量交换的重要过渡区。研究北部陆坡区复杂的地形地貌,有助于深化对南海北部陆缘海底地质活动与环境变化的认识,并为资源勘探与工程建设提供基础地质信息支撑。本研究基于全球水深地形图（General Bathymetric Chart of the Oceans,GEBCO）数据及实测多波束数据,对南海北部陆坡的地形地貌进行研究,识别出不同的地貌类型,并探讨其形成和发展的控制因素。研究表明,南海北部陆坡发育有海台、海山、海丘、海槽、海底峡谷以及冷泉地貌类型。南海北部陆坡地形地貌的发育和演化主要受控于构造活动及火山活动,而外动力地质作用如沉积输运、海平面变化及甲烷流体的活动等,都对研究区的地形地貌做了进一步的改造,使之更加复杂。     

Depositional architecture and developing settings of large-scale incised valley and submarine gravity flow systems in the Yinggehai and Qiongdongnan basins, South China Sea

In the Ying-Qiong basins in the South China Sea developed a set of giant inner shelf slope and submarine gravity flow deposits in the Ying-Huang formations since the Late Miocene. These deposits can be classified into 9 sequences in which slope slump-debris flow, slope fan and particularly, the large-scale axial basin-floor incised valley fills have been recognized. They were distributed in a distinctive pattern attributed to tectonic control. The development of shelf slopes and abyssal plains in the basins was related to the last episode of rapid subsidence and a large amount of sediment inputs. Large-scale basin-floor incised valleys, formed during the late Miocene and Pliocene, indicate several major sea level falls that occurred in the South China Sea.     

Cenozoic stratigraphy of Taiwan: Window into rifting, stratigraphy and paleoceanography of South China Sea

Shallow marine sequences of the northern South China Sea (SCS) are uplifted and exposed by plate convergence in the Taiwan mountain belt. These deposits provide detailed geological information about the rifting event, stratigraphy, sedimentology, paleoclimate and paleoceanography of the shallow SCS to compare with what are recorded in the ODP 1148 deep-sea core. Seismic surveys and marine micropalentological studies show that Eocene sequences in the offshore Taiwan Strait and onland Taiwan mountain belt are all deposited in rifting basins and are covered unconformably by the Late Oligocene-Neogene post-rifting strata. Between syn-rifting and post-rifting sequences, there is a regional break-up unconformity throughout the island. Early Oligocene and Late Eocene strata are missing along the break-up unconformity equivalent to the T7 unconformity in the Pearl River Mouth Basin off south China. This may suggest that the SCS oceanic crust could have initiated between 33 and 39 Ma. Neither obvious stratigraphic gap nor slumping features are found in the Oligocene-Miocene transition interval of Taiwan. This observation highly contrasts with what has been documented from the ODP 1148 deep-sea core. This suggests that the stratigraphic gap and slumping features could only be recorded in the SCS deep sea region, but not in the shallow shelf near Taiwan. Compared to the Middle Miocene paleoceanographic re-organization events in the SCS deep sea, the geological history of the Taiwan shallow sequence shows changes of in sedimentation and faunal composition. Due to the Antarctic glacial expansion at~14 Ma, Middle to late Miocene strata of the Western Foothills show progressive regression sedimentations associated with a decrease of benthic foraminif-eral abundance and a sharp faunal turnover event. Many Early-Middle Miocene endemic benthic foraminifers were extinct in 14-13 Ma and new benthic foraminifers of the Kuroshio Current fauna appeared from 10.2 Ma, comparable with new occurrence of Modern benthic foraminifers at 9 Ma in the Java Sea area. This reveals that the Western Boundary Kuroshio Current in the North Pacific could initiate from 10-9 Ma due to closures of the Indo-Pacific seaways by convergent tectonics between the Australian Continent and the Indonesian Arc in 12-8 Ma. Subduction of the SCS oceanic lithosphere since the Middle Miocene resulted in formation of the Hengchun Ridge accretionary prism and the North Luzon Arc. Occurrence of these two bathymetric highs ( 2400 m) since the Middle Miocene and closures of the inter-arc passages in the North Luzon arc in the last 3.5 Ma would control the water exchanges between the West Pacific and the deep SCS. Accordingly, the tectonic evolution in the Central Range-Hengchun Peninsula accretionary prism and the arc-forearc Coastal Range not only control directly the route for water exchanges between the West Pacific and the SCS, but also indirectly shows a great influence on the geochemistry of deep SCS waters. The latter is best shown by much negative carbon isotope values of benthic foraminifers in the ODP 1148 deep-sea core than the West Pacific records in the last 14 Ma.     

南海深海盆的沉积充填

依据大洋钻探井及地震剖面资料,定量确定南海同扩张期和后扩张期深海盆沉积充填差异及沉积物来源变化。研究显示,南海深海盆自渐新世(32 Ma)开始形成,随着南海二次扩张海盆范围逐渐扩大,海盆内主要充填火山碎屑角砾岩及火山灰,碳酸盐岩、超微化石软泥,泥质粘土、粉砂质粘土、泥岩及粉细砂岩。深海盆充填主要沉积物为晚中新世(11.6Ma)以来的陆源碎屑沉积,丰富陆源碎屑的供给与南海闭合过程中同期区域构造事件(如青藏高原快速隆升、菲律宾板块俯冲)密切相关,也与晚中新世以来东亚季风增强以及源区强烈的风化剥蚀有关。     

A regional tectonic event of Katian (Late Ordovician) age across three major blocks of China

The present paper deals with a tectonic event of Late Ordovician age affecting three blocks of China,i.e.South China,North China and Tarim.In the North China and the Tarim platforms,as well as their marginal belts,there was a regional uplift during the early Katian Stage of the Ordovician.The uplift was indicated by the unconformities between the Ordovician successions and overlying late Paleozoic strata.New biostratigraphic studies of conodonts and graptolites from many sections at Longxian and Yaoxian,North China shows that the youngest Ordovician strata are of the early Katian age corresponding to graptolite Diplacanthograptus spiniferus Biozone.The same level has been recognized to represent the uppermost Ordovician in the platform area of Tarim,whereas in the marginal belt the top boundary of the Ordovician is slightly younger,corresponding to the graptolite Dicellograptus complanatus Biozone.Thus,the regional uplift in North China and Tarim is shown by the disconformity between the early Katian strata and Late Paleozoic strata,the onset coinciding with that of the Kwangsian Orogeny in South China.The designation Kwangsian Orogeny later fell into disuse and was replaced by the term Caledonian Orogeny.However,in terms of geographic location,tectonic nature,and the timing of activity,the Caledonian Orogeny differs significantly from the orogenic event in South China,and the continued use of this term in South China is inappropriate and misleading.     

南海北部陆缘黏土矿物组合特征与地质意义

采用沉积矿物分析方法对南海北部九口探井渐新世—中新世沉积物进行系统的黏土矿物分析.结果表明:南海北部沉积物黏土矿物组成随时间及空间呈现规律性变化,黏土矿物伊/蒙转化深度具有自北向南逐步变浅的规律,与地温梯度升高变化趋势基本一致,这种黏土矿物伊/蒙转化的变化规律反映了南海北部洋陆过渡地壳减薄,莫霍面抬升,热流值升高的趋势.通过黏土矿物组合演变特征与热流变化趋势的相关关系,可以预测区域性温度场变化规律,加深对南海北部洋陆过渡地壳厚度变化的认识.     

华南早燕山中晚期挤压构造事件识别及其成矿效应

华南是中国重要的钨、锡、铋、铜、银、锑、汞、稀有、重稀土、金和铅锌多金属重要成矿省,成矿时代以中-新生代为主。众多学者通过野外调查、构造变形解析、科学深钻、年代学研究等方法对华南各个区域进行构造地质学研究,并取得重要成果。但对整个华南中生代构造演化过程的认识依然存在分歧,这主要归咎于不同学者根据局部研究成果或单一地质要素对华南构造演化进行讨论。系统总结前人在华南研究的成果,对华南早燕山期古地层产出状态、古地理变化、古构造应力场、构造变形样式、岩浆记录等多种地质要素进行归纳。初步认为华南早燕山中晚期处于SEE-NWW或近EW向挤压构造背景下,时间界限大致为170~135 Ma,推测挤压事件可能是成矿大爆发开始的前奏,挤压作用将成矿物质预富集,形成矿化区域,为后期成矿作用提供物质基础及成矿有利空间。