张家口-蓬莱断裂带渤海段晚第四纪活动特征

张家口-蓬莱断裂带是华北地区一条显著的地震带.利用最新获得的高分辨率浅层地震资料研究了渤海海域内该断裂带晚第四纪以来的活动特征.研究表明:在渤海,张家口-蓬莱断裂带主要由沙西断裂、埕北断裂、沙南断裂、沙东北断裂、柏各庄断裂、石臼坨3号断裂、渤中2号断裂和BZ29断裂等一系列NW走向断裂组成,走向在290°～310°之间;在浅层沉积物中各断裂由多条次级小断裂组成;晚第四纪以来主要表现出强烈的垂向运动特征,具有正断性质;海域各断裂的最新活动时代为晚更新世(Q3)末期-全新世(Q4)初期,并具有相同的活动趋势,在20 ka B.P.和60 ka B.P.左右活动强烈,统计计算显示平均垂向活动速率分别为0.15 mm/a和0.1 mm/a,近20 000 a以来的垂向活动速率超过0.06 mm/a.     

苏鲁地体胡家林和梭罗树三叠纪变质超基性岩U-Pb、Lu-Hf和O同位素地球化学研究

胡家林超基性岩单矿物氧同位素组成基本上接近正常地幔值（石榴石4.7‰~5.4‰)。梭罗树超基性岩及其共生榴辉岩具有氧同位素正异常（超基性岩中石榴石9.8‰~10.4‰;榴辉岩中石榴石9.0‰~12.1‰)，指示超基性岩和榴辉岩原岩可能在板块俯冲之前，在浅层或地表环境中经历过蛇绿岩套顶部相似的低温热液蚀变。胡家林超基性岩样品中的变质锆石年龄227.2±2.4 Ma，可能代表俯冲板块经峰期超高压变质后，折返初期从金刚石榴辉岩相降压至柯石英榴辉岩相过程中流体活动和错石结晶的年龄。梭罗树超基性岩样品中变质锆石的一组变质年龄240.4±2.4 Ma代表了板块俯冲至超高压峰期变质之前流体活动过程中锆石的结晶年龄，而另一组变质年龄217.1±3.3 Ma代表了板块折返过程中高压榴辉岩相重结晶条件下的锆石结晶年龄。从变质锆石到重结晶锆石，其Th/U和176Lu/177Hf呈现出相似的变化趋势，可能指示了变质作用对锆石中的U-Th-Pb同位素体系和Lu-Hf同位素体系产生相似的地球化学效应。梭罗树超基性岩可能来源于俯冲地壳内部的“残留地幔”。胡家林超基性岩重结晶锆石中继承的放射成因铅或者来源于俯冲地壳与仰冲盘底部石榴辉石岩相地幔发生的壳幔相互作用而导致碎屑锆石的重结晶；或者来源于超基性岩岩浆在板块俯冲前，通过底侵作用上升侵位与地壳物质发生混染形成岩浆锆石，这种岩浆错石在超高压变质过程中经历了重结晶。     

硅岩的Rb-Sr同位素组成特点及其地质意义

通过对扬子地台和东昆仑山地区的不同时代、不同成因、成分上差异较大的硅岩Rb-Sr同位素组成的对比研究，探讨其物源和形成环境，利用所测Rb-Sr等时线年龄，有效的解决硅岩的地层年代，开创硅岩测年的应用前景。     

Distribution of the organic matter in the channel-levees systems of the Congo mud-rich deep-sea fan (West Africa). Implication for deep offshore petroleum source rocks and global carbon cycle

The quantity and the source of organic matter preserved in the Recent turbiditic channel-levees systems around 4000 m-depth off the Congo River were determined using bulk geochemical approaches (Rock-Eval, elemental and isotopic analyses) as well as molecular and optical analyses on selected samples. These mud-rich sediments contain high amount of organic matter (3% Corg on average), the origin of which is a mixture of terrestrial higher-plant debris and deeply oxidized phytoplanktonic material. Although the relative contribution of continental source versus marine source of the organic matter cannot be precisely quantified, the continental fraction appears significant (at least 70–80%) especially for such depths and distances from the coast. The organic matter distribution appears very homogeneous at different scales, from the single turbiditic event to the entire levee, and changes in accumulation rates have a little impact on the quantity and quality of preserved organic matter.     

Improved understanding of petroleum migration history in the Hongche fault zone,northwestern Junggar Basin (northwest China): Constrained by vein-calcite fluid inclusions and trace elements

Calcite veins and cements occur widely in Carboniferous and Permian reservoirs of the Hongche fault zone, northwestern Junggar Basin in northwest China. The calcites were investigated by fluid inclusion and trace-element analyses, providing an improved understanding of the petroleum migration history. It is indicated that the Hongche fault behaved as a migration pathway before the Early Cretaceous, allowing two oil charges to migrate into the hanging-wall, fault-core and footwall reservoirs across the fault. Since the Late Cretaceous, the Hongche fault has been sealed. As a consequence, meteoric water flowed down only into the hanging-wall and fault-core reservoirs. The meteoric-water incursion is likely an important cause for degradation of reservoir oils. In contrast, the footwall reservoirs received gas charge (the third hydrocarbon event) following the Late Cretaceous. This helps explain the distribution of petroleum across the fault. This study provides an example of how a fault may evolve as pathway and seal over time, and how reservoir diagenetic minerals can provide clues to complex petroleum migration histories.     

墨西哥湾南部晚侏罗纪主力烃源岩的形成条件

通过对墨西哥湾不同时代可采储量的分布特征和油源对比资料的分析认为,晚侏罗纪烃源岩是墨西哥湾南部最主要的烃源岩。资料显示,晚侏罗纪优质烃源岩形成的主控因素是稳定的构造和沉积条件以及超咸的还原环境,其中,"世界顶级"的晚侏罗纪提塘阶烃源岩主要形成于超咸的碳酸盐岩和/或蒸发岩沉积环境,属半深海还原环境,有机质以藻类为主,推测烃源岩中的有机质可能与极端干旱气候条件下的藻类勃发有关。     

南海东北部新构造运动及其动力学机制

南海东北部地处欧亚板块与菲律宾海板块的交汇区,新构造运动活跃。根据地震活动性、震源机制解和GPS资料对该区的新构造活动特征进行分析,在此基础上讨论该区新构造运动的动力学机制。分析发现,菲律宾海板块NW向俯冲对该区的影响最为显著,导致了该区较强的地震活动性以及与俯冲方向一致的构造应力场。而印藏碰撞产生的侧向应力传递也影响到该区,控制华南地块向SE方向运动,并与菲律宾海板块的NW向俯冲共同作用,使华南地块在SE向运动的同时伴有逆时针旋转。印藏碰撞的SE向应力传递对俯冲产生的NW向水平挤压的抵消作用,使得地震活动性自东向西减弱以及构造应力场P轴方位角顺时针旋转。在这一背景下,区内滨海断裂带的活动控制了该区的地震、海岸带构造升降等新构造运动。     

Controlling factors on the morphology and spatial distribution of methane-related tubular concretions – Case study of an Early Eocene seep system

Up to 10 m in length and >1 m in diameter tubular, calcite-cemented sandstone concretions are hosted by the faulted Dikilitash unconsolidated sands and sandstones. These structures document shallow subsurface pathways of Early Eocene methane seepage in the Balkan Mountains foreland (NE Bulgaria). Their exceptional exposure allowed a unique study of the factors governing the morphology and spatial distribution of such fossilized fluid conduits. The large dimensions and subvertical, cylindrical shape of the most common tube type primarily reflects the buoyancy-driven, vertical path of an ascending gas-bearing fluid through permeable, mainly unconsolidated sandy host sediments. Tube morphology was also influenced by local stratigraphic anisotropies and might as well document differences in former seepage conditions. Mapping of >800 tubular concretions showed the NNW–NNE elongation and alignment of tube clusters and massive cemented sandstone structures. This suggests that Paleogene fault systems played a major role in directing the movement of fluids. However, within a single tube cluster, tubes are preferentially aligned, over distances up to 50 m along directions at an angle between 10° and 36° with respect to the inferred NNW–NNE, cluster parallel fault traces. In addition, cylindrical tubes of analogue dimensions are aligned over distances >100 m along N15° to N25°-oriented directions. It is hypothesized that this spatial geometry of tubular concretions reflects the complex geometry of deformations structures in fault damage zones along which fluids were preferentially channelled.     

Petroleum composition in the Cuu Long Basin (Mekong Basin) offshore southern Vietnam

The Cuu Long Basin (Mekong Basin) is a rift basin off southern Vietnam, and the most important petroleum producing basin in the country. However, information on petroleum type and characteristics has hitherto been largely unavailable to the public. This paper presents petroleum geochemical data on nine oil samples from four different producing fields in the Cuu Long Basin: the Dragon (Rong), Black Lion (Sutu-Den), Sunrise (Rang ?ong) and White Tiger (Bach Ho) Fields. The oils are highly paraffinic with bimodal normal alkane distributions and show moderate pristane to phytane ratios and a conspicuous hyperbolic decrease in abundance with increasing carbon number of hopane homologues from C₃₀ to C₃₅. The TPP-index of Holba et al. (Holba, A.G., Dzou, L.I., Wood, G.D., Ellis, L., Adam, P., Schaeffer, P., Albrecht, P., Greene, T., Hughes, W.B., 2003. Application of tetracyclic polyprenoids as indicators of input from fresh–brackish water environments. Organic Geochemistry 34, 441–469) is equal to 1 in all samples which in combination with tricyclic triperpane T26/T25 ratios >1 and the n-alkane and hopane distributions mentioned above provide a strong indication of an origin from lacustrine source rocks. This is supported by the absence of marine C₃₀ desmethyl steranes (i.e. 24-n-propylcholestanes) and marine diatom-derived norcholestanes. Based on the overall biological marker distributions, the lakes probably belonged to the overfilled or balanced-fill types defined by Bohacs et al. (Bohacs, K.M., Carroll, A.R., Neal, J.E., Mankiewicz, P.J., 2000. Lake-basin type, source potential, and hydrocarbon character. An integrated sequence-stratigraphic–geochemical framework. AAPG Studies in Geology 46, 3–34). The oils were generated from source rocks at early- to mid-oil-window maturity, presumably Oligocene lacustrine shales that are present in the syn-rift succession. Oils from individual fields may, however, be distinguished by a combination of biological marker parameters, such as the oleanane index, the gammacerane index, the relative abundance of tricyclic terpanes, the proportions of diasteranes and 28-norspergulane, complemented by other parameters. The oils of the Cuu Long Basin show an overall similarity to the B-10 oil from the Song Hong Basin off northern Vietnam, but are markedly different from the seepage oils known from Dam Thi Nai on the coast of central Vietnam.     

松南十屋断陷深层油气成藏条件与模式研究

十屋断陷是断坳叠置的复合盆地,充填了巨厚的断陷地层。其深部地层包括登娄库组、营城组、沙河子组以及火石岭组。在十屋断陷深部沉积了沙河子组-营城组和登娄库组两套烃源岩和良好的储盖层组合;由于断陷构造运动,形成大量的断裂构造和不整合面,构成了油气运移的有效通道,同时还形成有效断裂、断鼻构造圈闭以及不整合圈闭。综合分析认为,十屋断陷深部具有有利油气成藏生储盖组合。主要有下生上储式、自生自储式和上生下储式三种成藏模式。