巴西桑托斯盆地C区块火成岩发育特征及对油气成藏的影响

桑托斯盆地盐下碳酸盐储层中火成岩分布广泛,以盆地C区块为解剖区,通过对区内火成岩岩石学、年代学以及CO₂气体同位素测试分析等,明确了区内火成岩发育特征,剖析了其对油气成藏的影响。C区块至少经历了阿普特期和圣通-坎潘期2期岩浆活动,其中阿普特期岩浆以喷发岩为主,经历了多次喷发,并伴有多次侵入;圣通-坎潘期岩浆规模较小,侵入比较随机。阿普特期岩浆多次喷发改造古地形,形成局部凸起,促成并控制了Itapema组介壳灰岩的沉积发育,形成了巨厚的火山岩-介壳灰岩复合体,不仅造成了局部构造反转和圈闭高点迁移,而且也促成了Barra Velha组优质微生物灰岩的发育。区块北翼属早期古隆,Barra Velha组也发育一定规模微生物灰岩滩体。圣通-坎潘期及之后岩浆活动伴生的CO₂大规模侵入,对烃类流体进行萃取和抽提改造,形成含凝析油的CO₂气藏。      

Early Cretaceous flora from coal-bearing strata of Markovsky Peninsula in South Primorye，Russia

The Early Cretaceous flora from the coal-bearing strata(Ussuri and Lipovtsy formations)in the Markovsky peninsula of South Primorye,Far East Russia,is reported in some detail in this paper.The flora containing over 80 species of about 50 genera can be divided into two assemblages.The paleofloristic characteristics and the comparisons of this flora with its coeval floras from the adjacent region of the eastern Heilongjiang of Northeast China,indicate the flora and its coal-bearing strata of the Markovsky peninsula can be compared to those of the Chengzihe and Muling formations of the Jixi area of Heilongjiang,representing probably the late Barremian and Aptian age,respectively.     

Zircon U-Pb geochronology and geological implications of granitoids from Sawuer Mountains in North Xinjiang, NW China

LA-ICP MS zircon U-Pb dating results of granites from Sawuer Mountains in North Xinjiang, NW China, are reported based on 1:50 000 regional geologic surveys. Zircon U-Pb dating shows that the granitoids have magmatic crystallization age of 320 ±2 Ma. In addition, zircons with ages of 341 ～358 Ma could be subdi- vided into two groups, i.e. , Group 1 with a weighted mean age of 342 + 3 Ma and Group 2 with a weighted mean age of 354 + 2 Ma. The petrology and geochemistry of granitoids from Sawuer Mountains suggest their mixed origin. The granite from Sawuer Mountains occurred in an extensional setting, most probably related to post-orogenic processes during the closure of the Peo-Asian Ocean; namely, represent the tectonic setting shif- ted from compress to post-collisional setting.     

Archaeal diversity and abundance within different layers of summer sea-ice and seawater from Prydz Bay,Antarctica

Fluorescence in-situ hybridization （FISH） and 16S rRNA gene clone library analyses were used to determine the abundance and diversity of archaea in Prydz Bay, Antarctica. Correlation analysis was also performed to assess links between physicochemical parameters and archaeal abundance and diversity within the sea-ice. Samples of sea-ice and seawater were collected during the 26th Chinese National Antarctic Research Expedition. The results of FISH showed that archaea were relatively abundant within the top layer of the sea-ice, and correlation analysis suggested that the concentration of 4NH＋ might be one of the main factors underlying this distribution pattern. However, using 16S rRNA gene libraries, archaea were not detected in the top and middle layers of the sea-ice. All archaeal clones obtained from the bottom layer of the sea-ice were grouped into the Marine Group I Crenarchaeota while the archaeal clones from seawater were assigned to Marine Group I Crenarchaeota, Marine Group II Euryarchaeota, and Marine Group III Euryarchaeota. Overall, the ifndings of this study showed that the diversity of archaea in the sea-ice in Prydz Bay was low.     

陕西蓝田红门寺地区丹凤群构造变形特征

本文对蓝田红门寺地区丹凤群的变形特征,提出至少经历过三期主要构造变形及混合岩化作用。     

Chemical indexes of Paleoproterozoic sedimentary rocks from Liaohe Group,North China Craton:Implications for paleoclimate and provenance

Paleoproterozoic supracrustal materials have been widely identified in North China Craton, such as the Liaohe-, Hutuo-and Lyuliang groups. The Liaohe Group in the eastern part of the North China Craton is dominated by deformed and metamorphosed sedimentary and volcanic successions. Compared with that of the coeval volcanic rocks, geochemistry of the sedimentary rocks from the Liaohe Group has rarely been studied in detail, which can possibly provide information on the paleoclimate and provenance. The authors analyzed the whole-rock and detrital zircon geochemistry of sedimentary rocks from the Liaohe Group against a uniform process and proposed their different ways of paleoweathering of the lower and upper formations. That is to say, although the lower and upper formations within the Liaohe Group might be derived from the similar source composition in a tectonically active setting, the paleoclimate that they experienced was not exactly the same. The predominant derivations are the Paleoproterozoic granitoids and basalts within the Liaohe Group, with minor input of Archean continental crust. This study highlights the contributions of the Paleoproterozoic mafic sources, which has been generally overlooked in the previous researches.     

豫西狮子坪地区秦岭群中的斜长角闪岩-大理岩组

在河南卢氏狮子坪地区的秦岭群中出露一套变质地层,其组成特点与各地已知的秦岭群明显不同,主要岩石类型为斜长角闪岩、透辉斜长变粒岩和含石墨大理岩。在构造迭置关系上这套变质地层位于秦岭群条带状长英质片麻岩层和云母片岩层之上,原始接触关系已不明朗,内部也难以逐层恢复层序,但内部三部分的迭置关系是明确的。作者提出这套变质地层应当作为一个独立的填图单位,进而建立岩组,并认为这可能是一套迭置于秦岭群之上的较新地层,但曾与秦岭群一道遭受了变质变形改造。     

Changes of taxonomical composition of Late Jurassic-Early Cretaceous palynofloras of Bureya Basin,Russia

The changes of taxonomical composition of the Late Jurassic-Early Cretaceous palynofloras are revealed,in the upper stream of Bureya River in Bureya Basin.The palynofloras are dominated as follows:the Berriasian one by ferns(Cyatheaceae,Dicksoniaceae,Osmundaceae),Classopollis and bisaccate pollen;the Valanginian-Hauterivian one by ferns(Cyatheaceae,Dicksoniaceae),Ginkgocycadophytus and bisaccate pollen;the Barremian one by ferns(Cyatheaceae,Dicksoniaceae);the Aptian one by ferns(Cyatheaceae,Dicksoniaceae,Gleicheniaceae) and Ginkgocycadophytus;and the Albian one by ferns(Schizaeaceae) and bisaccate pollen.In the Albian the floral diversity raises with the angiosperms appearing.     

Changes of taxonomical composition of Late Jurassic Early Cretaceous palynofloras of Bureya Basin,Russia

The changes of taxonomical composition of the Late Jurassic-Early Cretaceous palynofloras are revealed,in the upper stream of Bureya River in Bureya Basin.The palynofloras are dominated as follows:the Berriasian one by ferns (Cyatheaceae,Dicksoniaceae,Osmundaceae), Classopollis and bisaccate pollen;the Valanginian-Hauterivian one by ferns (Cyatheaceae,Dicksoniaceae), Ginkgocycadophytus and bisaccate pollen;the Barremian one by ferns(Cyatheaceae,Dieksoniaceae);the Aptian one by ferns(Cyatheaceae,Dieksoniaceae,Gleicheniaceae)and Ginkgocycadophytus;and the Albian one by ferns(Schizaeaceae)and bisaccate pollen.In the Albian the floral diversity raises with the angiosperms appearing.     

Changes of taxonomical composition of Late Jurassic- Early Cretaceous palynofioras of Bureya Basin, Russia

The changes of taxonomical composition of the Late Jurassic- Early Cretaceous palynofloras are revealed, in the upper stream of Bureya River in Bureya Basin. The palynofloras are dominated as follows： the Berriasian one by ferns （Cyatheaceae, Dicksoniaceae, Osmundaceae）, Classopollis and bisaccate pollen; the Valanginiar-Hauterivian one by ferns （Cyatheaceae, Dicksoniaceae）, Ginkgocycadophytus and bisaccate pollen; the Barremian one by ferns （Cyatheaceae, Dicksoniaceae）; the Aptian one by ferns （Cyatheaceae, Dicksoniaceae, Gleicheniaceae） and Ginkgocycadophytus; and the Albian one by ferns （Schizaeaceae） and bisaccate pollen. In the Albian the floral diversity raises with the angiosperms appearing.     

湘东北—桂北中元古界岩石地球化学特征

湘东北—桂北中元古代冷家溪群和四堡群的变玄武岩类显示过渡型拉斑玄武岩类的地球化学特征,变砂岩类和变泥岩类（绢云板岩类）显示大陆边缘的砂岩类和泥岩类的地球化学特征。根据岩石地球化学和沉积相（低密度流复理石建造）特征,推测湘东北冷家溪群和桂北四堡群主要形成于大陆边缘深水环境。     

岫岩北瓦沟构造序列及构造演化

在吕梁造山旋回期间(1900Ma)北瓦沟辽河群经受了多幕变质和多期变形的改造,可识别出三组皱褶构造:1.早期近东西向片内平卧褶皱,由固态流变机制形成(F_1);2.枢扭北北西—南南东向不对称褶皱(F_2);3.北东向开阔褶皱构造(F_3)。此外,还发育与褶皱构造相关的布丁构造和布丁褶皱。赋存在辽河群中的铅锌矿床遭受了强烈的改造作用并严格受构造控制。     

甘肃省文县石坊群孢子化石的发现及地质意义

在测制甘肃文县地区石坊群地层剖面中发现了孢子化石,共计14个属,56个种,将其与贵州独山、都匀地区的早、中泥盆世孢子化石组合对比,发现组合特征基本一致。因而确定了石坊群地层时代属早、中泥盆世,为石坊群地层划分、时代确定及地质构造发展史研究提供了可靠的依据。     

陕西蟒岭地区宽坪群的构造演化

本文将宽坪群的构造演化序列分为两大阶段,即海西一印支运动及其以前的以褶皱为主的变形;燕山运动以来的以断裂为主的变形。两个阶段所形成的构造均沿着北西西和北东两个方向延伸,显然它们是北西西和北东两个方向的构造波系在蟒岭地区活动的表现,并由此形成了该区的斜向构造格局。     

Preliminary study on the spore-pollen assemblages found in the Cenozoic sedimentary rocks in Grove Mountains, east Antarctica and its climatic implications

Glaciogene sedimentary rocks have been found in modem tills of the Grove Mountains, east Antarctica during the 1998 - 1999 Chinese National Antarctic Research Expedition （CHNARE）. Based on the lithilogic and sedimentary features, these sedimentary rocks are correlated with Cenozoic sedimentary strata of the Pagodroma Group in the neighboring Prince Charles Mountains and the Sorsdal Formation in VestFold Hills. Sedimentary clasts contain sparsely Late Tertiary spores and pollens, including ： Toroisporis （ Lygodiaceae）, Osmunda, Granulatisporites （ Pteridaceae？） , Polypodiaceae, Podocarpus , Araucariaceae, Artemisia , Rhus , Nothofagidites , Proteacidites （Proteaceae） , Quercus , Fraxinoipollenites （ Oleaceae ） , Oleoidearumpollenites（ Oleaceae ）, Operculumpollis, and Tricolpopollenites. Most of the pollen and spores contained in these samples originate from local sources according to the conditions of their preservations as well as correlations with the microfossil assemblages found in the neighboring areas. The majority of the pollen assemblages, as represented by Podocarpus and Nothofagus, belong to the Weddellian biogeocenose, however some exotic components from the old sedimentary basement rocks may have been included during erosion of the proximal ice sheet. If the source areas of glaciogenic sedimentary rocks that bear the pollen and spores are assumed to be local, or in the up glacier areas, the pollen assemblages in these samples might represent an inland flora during a warmer period of the ice-sheet evolutionary history. The finding of the Artemisia and Chenopodiaceae in the pollen assemblages implies that they may belong to late Tertiary （most probably Pliocene）. The absence of diatoms in the samples analyzed may indicate that there are no Cenozoic marine strata in the interior of the east Antarctica beyond the Grove Mountains. The significances of the finding of the Nothofagus in these pollen assemblages are discussed on the basis of current knowledge about the age, distribution and ecological conditions of this kind of fossils found in Sirius Group or other strata outcropped in Antarctica. As a preliminary conclusion, we think that the existence of the Cenozoic glaciogenenic rocks and their pollen assemblages present new evidence for a large scale glacial retreat history in Grove Mountains of east Antarctica, and thus support a dynamic East Antarctic Ice Sheet （EAIS）. This is consistent with the interpretations of Webb et al. （1984）.     

Sedimentary Precambrian deposits in southwestern Transbaikalia (Siberia): phytoliths content, lateral correlations and geodynamics

The Baikal Group is one of the most important stratigraphic units in the geology of East Siberia (Upper Riphean). This paper focuses on litological-facies features based on the analysis of organic remains (stromatolites, microphitolites and microfossils), in order to better precise the age and environmental deposit conditions of the Baikal Group. The results are used to draw a correlation between all the Precambrian of deposits of the South of East Siberia. The stratigraphy of the Baikal Group is then compared to the geodynamic evolution of this region, characterized by the break-up of the supercontinent Rodinia and subsequent opening of the Paleo-Asian Ocean. Stratigraphic analogs to the Baikal Group display in most areas deposits of various minerals (complex ores, phosphoresces, bauxites etc. have been dated of the same age), so the present study would also provides an economic interest.     

荣成超单元的基本特征

笔者于１９８８－１９９２年参加１：２０万海阳、潮里、文登和威海四幅的区调工作。成果表明：广泛分布于胶东东部，即玉林店—午极、威海及荣成以南一带前人划归胶东群地层的一套片麻岩，实为变质变形花岗质侵入岩。由早到晚可划分为大时家、腾家、威海、御驾山和邱家五个单元，归并为荣成超单元。这一进展使得该区地质图面貌发生了重大改观。     

浙江雁荡山地区晚中生代火山-沉积岩系地层归属讨论

浙江雁荡山地区晚中生代火山-沉积岩系的地层归属,存在磨石山群和永康群两种截然不同的认识.本文在详细分析对比了该区与浙东南磨石山群和永康群的地层层序、岩相组合、接触关系,古生物组合,同位素地质年龄,Nd同位素体系特征以及火山构造类型等方面的资料,认为除原划为永康群盆地外,仅桥下地区有面积不大的永康群,其余均为早白垩世早期的磨石山群,而不是早白恶世晚期至晚白垩世早期的永康群.特别是在永嘉枫林村北,首次发现并证实了不整合覆于震旦系浅变质岩之上的大爽组地层,为浙东南沿海晚中生界火山-沉积岩系的划分对比提供了坚实的基础.     

毛塞几比盆地外陆架-陆坡区阿尔比阶-土伦阶沉积特征及成藏体系

近几年来,多个大型油气发现使得毛塞几比盆地成为国际油气勘探的热点区域。基于地震资料和钻测井资料系统开展了沉积相以及沉积模式研究、储层物性分析、烃源岩评价以及成藏体系分析工作。研究结果表明:①盆地中南部外陆架广泛发育多期强制海退三角洲沉积体系,受基准面旋回控制,强制海退三角洲顶积层遭受剥蚀,砂体被搬运到三角洲前部,形成强制海退砂,砂体在陆架边缘附近广泛分布;陆坡类型控制了深水扇差异分布模式,南部断控型陆坡控制了深水扇的分布,深水扇主体发育在陆坡坡脚,距离陆架边缘较近,北部平缓型陆坡下重力流搬运较远,深水扇主体远离陆架边缘,据此建立了南部断控型陆坡控砂模式和北部缓坡型陆坡富砂模式。②外陆架强制海退三角洲和北部缓坡型深水扇储层条件好,测试产能高,受胶结作用和滑塌碎屑影响,南部陡坡型深水扇储层物性差。③油源对比表明,油气主要来自下白垩统阿普第阶-阿尔比阶与上白垩统赛诺曼阶-土伦阶海相烃源岩,阿普第阶-阿尔比阶烃源岩以Ⅱ₂型干酪根为主,主要生气;赛诺曼阶-土伦阶海相烃源岩以Ⅰ型干酪根为主,主要生油。④研究区发育3套有利成藏体系,分别为阿尔比阶陆架边缘成藏体系、阿尔比阶-土伦阶陆坡坡脚成藏体系以及赛诺曼阶陆坡远端成藏体系,其中陆架边缘成藏体系与陆坡远端成藏体系勘探潜力更大,是下一步勘探的重点。      

胶东西北部地区同位素地质年代学研究

一、前言对于胶东西北部地区的太古代胶东群变质杂岩,前人测得其K-Ar同位素地质年龄值仅有1664Ma;玲珑花岗杂岩体的同位素地质年龄值变化在46—476Ma之间。笔者认为上述同位素地质年龄值与它们所代表的地质体的地质特征不相一致。经笔者研究认为:胶东群和玲珑花岗杂岩均遭受了较强烈的硅、碱质交代作用。这种交代作用是发生在埋深、高温条件