塔南凹陷南屯组油藏类型及其分布特征

塔南凹陷南屯组现今的复合箕状断陷结构,是由盆地内部的多个断块、翘倾掀斜分割改造的缓坡—沉积中心—沉降中心—陡坡组成大型断陷盆地后形成的。通过构造、沉积、反演和试油资料的综合分析,发现区内油气藏类型及其展布受沉积过程、同生断层及后期构造的控制,与普通的陆相箕状断陷盆地明显不同。缓坡一侧的翘倾掀斜部位主要为三角洲前缘储集砂体,发育断层分割或遮挡的构造-岩性油气藏;沉积中心的储集砂体主要为远岸扇和三角洲前缘成因,多发育透镜状岩性油气藏和构造-岩性油气藏;在沉积和沉降中心之间的翘倾掀斜部位为远岸扇储集砂体,多发育透镜状岩性油气藏和背斜-岩性油气藏;陡坡一侧的沉降中心主要为近岸水下扇储集砂体,以透镜状岩性油气藏为主,也可见到上倾尖灭岩性油气藏和构造-岩性油气藏。     

江苏高邮凹陷古近系戴南组一段物源体系和沉积相

对碎屑组分和重矿物的分析结果表明,高邮凹陷戴南组一段沉积时期,北部斜坡带的花庄、富民 北部和永安地区沉积物来自柘垛低凸起方向,联盟庄和马家嘴地区沉积物来自菱塘桥低凸起方向;南部陡坡带 沉积物来自通扬隆起,周庄地区沉积物来自东部物源区。戴一段沉积物母岩岩性以中-低级变质岩为主,中酸 性火山岩的分布较基性火山岩要广,深成岩较少或没有。根据岩心观察、录测井资料分析,及研究区物源体系 特征,认为高邮凹陷戴南组一段沉积时期,发育扇三角洲、三角洲、近岸水下扇和湖泊沉积。凹陷北部斜坡带 地形坡度较缓,来自柘垛低凸起和菱塘桥低凸起方向的沉积物呈点物源形式沿水下河道在缓坡带形成三角洲沉 积,物源供给量的差异导致三角洲朵体大小不同;凹陷南部陡坡带地形高差较大,在湖岸临近高地发育多条水 下河道,沉积物被剥蚀后呈多物源形式就近入湖沉积,加之母岩类型差异,在湖盆陡坡带形成近岸水下扇、扇 三角洲沉积体;凹陷西南部因汉留断层的存在造成三角洲前缘与前三角洲的高差,使原沉积的三角洲前缘沉积 物发生滑塌,并以线状物源形式在较深水处形成滑塌浊积扇;凹陷中部和砂岩及砂砾岩沉积体的侧翼和远端受 构造活动影响较小,物源供给不充分,发育湖泊相沉积。     

胜利油田博兴洼陷沙三段高青砂岩体沉积模式研究

为了预测砂体分布规律与岩性圈闭有利区带,指导下一步勘探,采用微观组分特征、岩石结构、粒度分布特征和沉积微相分析等方法,分析研究了高青砂岩体的沉积模式。研究表明,高青砂岩体的沉积微相有水下分流河道、河口砂坝、前缘席状砂沉积、砂泥互层沉积、前扇三角洲深水湖泊沉积。砂岩体的沉积模式分为三种：下部（G3）属（扇）三角洲水下部分沉积,中部（G2）属三角洲水下部分沉积,但湖泊中心和沉积中心进一步向南东方向迁移,上部（G1）与中部相似,但水下主分流河道以向南南东方向展布为主。根据高青砂体所处的构造位置及砂体与围岩的相互关系,确定了砂岩体的沉积环境为扇三角洲前缘与前扇三角洲。     

鄯勒油田西山窑组层序地层格架及其油气地质意义

运用层序地层学的基本原理和技术方法,建立鄯勒油田西山窑组层序地层格架,划分沉积相,并在此基础上分析层序地层格架内砂体的展布特征和油气的聚集规律,预测研究区岩性油气藏的类型及分布。研究结果表明：西山窑组整体经历了一个先进积、后退积的过程;西山窑组为一个三级层序,其中包含2个四级层序,该组由低位域（LST）的三角洲前缘沉积、湖侵域（TST）的三角洲平原沉积和高位域（HST）的湖相沉积组成。研究区基准面上升期可以寻找砂体上倾尖灭型岩性圈闭,基准面下降期可以寻找砂岩透镜体岩性圈闭。西一、二段沉积的三角洲河道砂体受后期构造运动的影响,可以形成砂体上倾尖灭型岩性油气藏;而西三、四段的湖相浊积砂体,可以形成砂岩透镜体岩性油气藏。     

中国东部箕状断陷湖盆扇三角洲与辫状河三角洲对比研究

中国东部箕状断陷湖盆短轴方向,常常发育扇三角洲和辫状河三角洲,二者均可形成良好的油气储集体,但在岩芯以及地球物理资料的识别上常常容易混淆。通过对它们沉积特征、地球物理资料特征、含油气性和控制因素的对比研究和分析认为:扇三角洲是陡坡带冲积扇直接入湖形成,地震反射特征为楔形前积,沉积物成分成熟度和结构成熟度均低于辫状河三角洲,沉积特征反映重力流和牵引流双重作用;辫状河三角洲是缓坡带辫状河入湖形成的三角洲,向湖盆方向推进较远,地震反射特征为叠瓦前积,沉积特征反映牵引流作用。扇三角洲易形成构造-岩性油气藏和岩性油气藏,有利相带为扇三角洲前缘水下分流河道、席状砂以及前扇三角洲容易发育的滑塌浊积扇;辫状河三角洲易形成地层-岩性油气藏和岩性油气藏,有利相带为辫状河三角洲平原辫状分流河道,辫状河三角洲前缘水下分流河道、河口坝、席状砂以及半深湖中的浊积岩体。古气候变化、构造-古地貌以及湖平面变化速率三者共同作用于扇三角洲和辫状河三角洲的沉积特征,其中构造-古地貌是主控因素。结合二者沉积特征差异,建立了中国东部箕状断陷湖盆扇三角洲和辫状河三角洲沉积模式图,以期能对相似构造背景下扇三角洲和辫状河三角洲的分析与研究提供一定的指导作用。     

饶阳凹陷沙河街组辫状河三角洲沉积特征及储集性

饶阳凹陷沙河街组主要为砾岩、含砾砂岩、砂岩、粉砂岩和泥岩构成的一套碎屑岩组合,根据沉积特征将其确定为辫状河三角洲沉积.该沉积三层结构清楚,由下而上出现前辫状河三角洲亚相、辫状河三角洲前缘亚相及辫状河三角洲平原亚相,呈明显的进积层序,主要发育辫状河道、洪泛平原、水下分流河道、水下分流河道间、河口坝和席状砂等沉积微相.据其岩性、沉积构造、粒度及沉积序列等特征,建立了沉积模式.从岩性特征看,沙河街组辫状河三角洲沉积物具有分布较广、储集物性较好的特点,辫状河三角洲前缘水下分流河道砂体和河口坝砂体储集物性最好,是下一步勘探的有利目标.     

松辽盆地保乾三角洲前缘带演变及其勘探意义

岩性油藏是松辽盆地最主要油藏类型之一,而三角洲前缘带是形成岩性油藏的有利相带。通过保乾三角洲沉积体系在不同地质时期沉积微相和沉积模式的深入研究,动态再现了保乾三角洲前缘带的演化过程。前缘带砂体经历了退积、进积和大规模迁移三个过程,物源方向总体由西南向西北方向逐步迁移,三角洲朵体形态由“深湖型”朵叶式逐步转变为“浅湖型”树枝式。保乾三角洲前缘带不同沉积时期的迁移规律对岩性油藏的勘探具有重要指导意义。     

新疆库车坳陷克拉苏冲断带白垩系辫状河三角洲沉积特征及其与储集层发育的关系*

新疆库车坳陷克拉苏冲断带白垩系巴什基奇克组一、二段是一套由细砂岩、中粗砂岩、含砾砂岩、粉砂岩及泥岩组成的碎屑岩组合。通过30余口钻井(包括6口新取心井)的岩心、测井、录井、薄片及粒度等资料的分析, 结合区域地质资料, 确认克拉苏冲断带巴什基奇克组一、二段发育砂质辫状河三角洲沉积。其岩性以岩屑砂岩为主;粒度概率曲线具有牵引流特征;砂体中发育楔状交错层理及冲刷、充填构造等丰富的强水动力沉积构造及间断正韵律;砂体延伸远、面积大展布稳定, 砂地比值高;发育水下分流河道、分流间湾等微相。据三角洲砂体的岩性、沉积构造及沉积序列等特征, 建立了三角洲沉积模式。稳定的构造背景、开阔的盆地、丰富的物源供给使得研究区辫状河三角洲前缘沉积非常发育, 其以水下分流河道沉积为主体, 物性好, 砂体延伸远, 可向盆地中央方向推进35～60km, 砂体纵横叠置, 为岩性油气藏的形成提供了有利的储集空间。     

准噶尔盆地莫北凸起侏罗系三工河组沉积演化及微相构成

运用高分辨率层序地层学原理将准噶尔盆地莫北凸起侏罗系三工河组划分为10个短期基准面旋回、2个中期基准面旋回。按照短期基准面旋回期次分析了该区沉积演化特征,在三工河组沉积期,研究区经历了辫状河三角洲前缘、曲流河三角洲前缘及滨浅湖的交替演化过程。不同的演化期,其微相构成具有很大的差别,辫状河三角洲前缘沉积主要由辫状河水下分流河道微相及河道间微相构成,河口砂坝及远砂坝不发育;曲流河三角洲前缘沉积微相有曲流河水下分流河道、支流间湾、河口坝、远砂坝及席状砂,以水下分流河道微相为主,河口坝较发育,远砂坝、席状砂次之;滨浅湖沉积微相由砂泥坪及滩坝构成。通过分析认为,在中期基准面下降到上升的转换位置,辫状河水下分流河道叠置连通广泛分布,为本区最有利的构造油气藏储集砂体;中期基准面上升和下降的中期,曲流河三角洲前缘水下分流河道及河口坝砂体发育,孤立状分布,为形成岩性油气藏的有利储集砂体。      

河北霸县凹陷兴隆宫地区沙三段岩性油气藏成藏条件与圈闭模式

裂谷型凹陷深层的油气勘探前景一直为众多学者所关注。兴隆宫地区紧临霸县生油洼槽,其沙三段埋深较大,勘探程度较低,少量探井证实这一些地区的沙三段具良好的油气成藏前景。应用石油地质学中的油气成藏理论,系统论述该区有利的岩性油气藏成藏条件与圈闭模式:沙三段圈闭接近沙四段、沙三段及沙一段的油源,具有优越的油气源条件;沙三段大型三角洲前缘与浊积扇等储层条件较好;沙三段同沉积构造与坡折带利于岩性油气藏形成;膏泥岩、盐岩及泥岩提供盖层与保存条件。而该区沙三段岩性油气藏成藏的圈闭模式可分为3个区带:陡坡带主要发育构造—岩性圈闭、小型三角洲前缘砂岩岩性圈闭;缓坡带以大型三角洲前缘砂岩岩性圈闭、地层超覆、地层不整合圈闭为主;而洼槽带以坡折附近的尖灭砂体圈闭为主。陡坡坡折之下发育扇三角洲前缘与浊积扇圈闭;缓坡坡折之下发育与低位三角洲、浊积扇及滩坝砂体有关的岩性圈闭。通过研究可以确定东部文安缓坡坡折带以下地区是目前岩性油气藏的最有利勘探区带。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)