华北板块西南缘义马盆地中侏罗世沉积相及古地理

义马盆地位于华北板块西南缘,是河南省境内唯一可采的中生代煤田,位置特殊。为了揭示其中侏罗世阿林期-巴柔期的沉积相及其古地理演化特征,运用矿物岩石学、地球化学、沉积学及岩相古地理等方法,以义马盆地中侏罗世含煤岩系为例,进行地层划分及沉积相和古地理研究。研究结果表明,研究区中侏罗世含煤岩系属阿林期-巴柔期,该时期主要发育冲积扇、辫状河、三角洲、湖泊等4种沉积相。利用单因素分析多因素综合作图法,以成煤期为节点,定量恢复了阿林期-巴柔期的古地理特征,从成煤期前到成煤期后,各优势古地理单元变化明显,具有冲积扇-三角洲-湖泊的变化规律,整体上是一个退积过程。     

The Pattern and Evolution of the Permian Palaeobiogeography and Tectonic Palaeogeography in Jilin and Heilongjiang Orogenic Belt

The orogenic belt locates between the North China plate and Siberia plate. The Permian palaeobiogeography and tectonic palaeogeography changed quickly and clearly. The line from Changchun to Yanji is an important palaeobiogeographic provincing line, which may be the collission suture belt of the North China plate and north middle massifs. The orogenic belt has been divided into 2 regions: the North middle massif region and the North Margin of North China plate, the pattern and evolution of Permian palaeobiogeography in the present area were discussed and the Permian biota mixture and its significants were analysed. Then, Based on the above, the Permian tectonic palaeogeography of the orogenic belt is reconstructed.     

渤海湾盆地古近纪古地理特征与油气*

渤海湾盆地是一个典型的内陆裂谷盆地,内部发育6个坳陷、4个隆起、54个凹陷和44个凸起。沉积盆地的含油气性与其古地理分布有密切的关系。利用渤海湾盆地各坳陷大量的录井、岩心、古生物、测井、地震资料及前人的大量文献和数据,对渤海湾盆地各坳陷古近系孔店组、沙河街组沙四段、沙三段、沙二段、沙一段、东营组进行了全区对比和统层。在此基础上,对冀中坳陷、济阳坳陷、临清坳陷内东濮凹陷各组段的沉积相进行了分析,编制了这些区域的古地理图;充分利用前人文献和科研报告中所编制的辽河坳陷、黄骅坳陷、渤海海域古近系各组段的古地理图,编制了渤海湾盆地孔店组、沙河街组沙四段、沙三段、沙二段、沙一段、东营组的古地理图。渤海湾盆地发育数十个含油气凹陷,每个凹陷中心的深湖亚相泥岩构成烃源岩,而在凹陷的边缘发育近岸水下扇、扇三角洲、三角洲、滩坝等砂体,构成重要的储集层,在有利的成藏条件下,凹陷中央的烃源岩向周围与之互层的储集层供烃形成油藏,在凹陷中央的烃源岩中,还发育了页岩油、页岩气、致密油气等非常规油气。因此,每个凹陷就是油气生成、运聚的基本单元,是一个独立的油气运移—聚集系统。生油凹陷的分布及其古地理特征控制了油气在渤海湾盆地古近系中的平面分布。     

鄂尔多斯盆地早侏罗世富县期沉积演化: 大洋缺氧事件前后陆地气候变化的响应*

托阿尔期早期早侏罗世大洋缺氧事件(T-OAE,~183.8 Ma)是一次全球性的地质事件,鄂尔多斯盆地下侏罗统富县组记录了此次地质事件的陆地响应过程。主要基于盆地东缘野外地质调查、扫描电镜及薄片分析,本次研究描述了盆地东北部富县组岩性、颜色和沉积序列,利用前人研究成果总结了富县期岩相古地理变化规律及沉积模式,认为富县期经历了由干旱到湿润的古气候变化: 富县组下部含植物化石较为丰富的白色砂砾岩及黑色、灰色泥页岩沉积于湿润气候时期,对应着盆地下切河谷发育期和填平补齐期; 而上覆的罕见植物化石的杂色、红色泥页岩为(富县期晚期)相对平坦地形条件下的沉积,对应着早、中侏罗世湿润气候背景下的一次干旱气候脉动,为托阿尔期大洋缺氧事件在陆相环境的气候响应,可由此进行富县组区域等时性对比。研究认为“粗富县”为下切谷内河流充填沉积, “细富县”形成于湖泊环境或河漫环境, “黑富县”和“白富县”是湿润气候条件下沉积产物,而“红富县”和“杂富县”为T-OAE期后干旱条件下形成。     

古地理与大地构造研究——简评目前的学术乱象*

野外调查是大地构造研究的重要基础。古地理及与之相关的沉积岩石学、古生物地层学、构造地质学等在大地构造研究中一直发挥着非常重要的作用,这在著名学者葛利普、黄汲清、王鸿祯等的著作中均有充分的体现。然而,自20世纪90年代以来,在以SCI为导向的评价体系指挥下,这些比较费时、费力的工作往往受到忽视。粉末化、简单化、模式化,新八股式的所谓研究,大行其道,成为一种时尚,形成一股十分有害的逆流。为扭转这种局面,科技界领导必须转变思想,改变政策,创造良好的科研环境,使中国的学术研究走上健康发展的道路。     

古陆、古隆与古地理

地质历史中有两种性质不同的陆源区:一是格林威尔期或更早期的构造事件,导致陆块拼合、固结、基底克拉通化,在边缘形成古老剥蚀区,称之为古陆;二是震旦纪至显生宙期间,由于洋陆转换、盆山转换构造事件,原沉积盆地反转成隆起,形成新的物源区,称之为隆起,可分为克拉通边缘隆起和克拉通内隆起。克拉通内隆起具穿时性,制约下伏盆地沉积物进积和上覆晚古生代海侵上超边界。穿时的界面在三维空间上即是沉积和层控矿床的储集空间,也是油气成藏的关键因素之一。而克拉通边缘隆起则具有构造障壁的作用。     

中国南方早奥陶世岩相古地理

中国南方是指西至金沙江-元江断裂、西北至龙门山断裂、北至城口-房县-襄樊-广济断裂，东北至郯城-庐江断裂,东至黄海和东海，南至南海的中国南方的广大地区。面积约2 000 000 km2 。在露头剖面和钻井部面的地层学和岩石学研究所取得的各种定量及定性资料的基础上，采用单因素分析综合作图法，编制出了中国南方下奥陶统新厂阶和宁国阶的各种单因素图以及相应的新厂期和宁国期岩相古地理图。在这两幅古地理图中，有7个主要的古地理单元，即滇西台地、康滇陆、扬子台地、斜坡、江南盆地、东南台地和华夏陆。前5个古地理单元属康滇古地理体系，后两个古地理单元属华夏古地理体系。这两幅古地理图的最大特征是定量，即每个古地理单元的划分和确定都有确切的定量的单因素图为依据和数据为依据。这种定量的岩相古地理图在我国南方早奥陶世还是首次出现。这种定量岩相古地理图在古地理学中是个重大的进展，对石油、天然气以及其他沉积矿的预测和勘探有重要的指导作用。     

Palaeogeographical influence on Late Eocene biosiliceous sponge-rich sedimentation, southern Western Australia

Late Eocene nearshore shallow-marine environments within the Bremer and western Eucla Basins of southern Western Australia were characterized by the thick deposition of spongolite and spiculite deposits. Epibenthic sponge communities dominated estuaries and topographically complex basin margin embayments-archipelagos, while cool-water carbonates with up to 10% sponges accumulated in open-shelf environments. The transition from a biosiliceous to calcareous epibenthos was related to the degree of palaeogeographical 'protection'. Within basement-protected embayments there was an offshore gradation from shoreface spongolite and pure spiculite to a muddy spiculite facies towards central embayment areas. Calcareous fossils are rare throughout embayment facies, but rapidly increase in more open outer archipelago areas. This depositional relationship occurred along 2000 km of the Late Eocene southern Australian coastline. Palaeogeographical protection from strong currents acted in concert with: (1) a planar, low-gradient inland topography with sluggish run-off, supplying fine-grained sediment, nutrients, and abundant dissolved silica; and (2) a microtidal setting, weak to moderate swells and opposing wind and Coriolis surface current forcing, which inhibited water exchange between embayments-estuaries and the open shelf. This situation led to an embayment water chemistry that encouraged prolific sponge growth. Calcareous spiculites record the mixing front between these embayment waters and normal open-shelf waters supporting cool-water carbonates.     

The Sedimentary Sequence and Palaeogeographic Changes of the South Yellow Sea Since the Olduvai Subchron

According to the alternation of terrestrial beds and transgressive beds, the sedimentary sequence of the South Yellow Sea since the Olduvai subchron can be divided into 15 stratigraphical intervals. According to the facies analysis, there are 7 transgressive beds and one bed with transgression marks, and classical transgressive-regressive facies sequence also appears in the major transgressive beds.Palaeogeographic evolution in the shelf area involved 4 periods: (1) 1.70-0.5 Ma B. P. was the stage for the development of the Palaeo-Yangtze River alluvial plain and delta. Tide influenced -river channel sediments formed during the Olduvai have been found in borehole QC2. The river mouth was located near 124°E and during the transgressive stage from 0.97-0.73 Ma B.P. to the east of 122.2°E, a large-scale undersea delta was formed. In the regressive stage, the shelf area became an alluvial plain. (2) 0.50-0.75 Ma B.P. was a multi-transgressive fluctuation stage during which 3 transgressive beds (HVI, HV, H