内蒙古呼鲁斯太石炭纪脊椎动物化石     

卢立伍  靳悦高  方晓思 《地质科技情报》2002,21(2):45-47

首次记叙了发现于内蒙古阿拉善左旗呼鲁斯大地区上石炭统土坡组上部和羊虎沟组下部的鱼类鳞片，其种类与在宁夏中卫纳缪尔期地层中发现的鱼类相似，均属古鳕类（Palaeoniscoids）；同时还记述了一枚产于土坡组上部的脊椎动物牙齿化石。  相似文献   

Discovery of Radiolarian Fossils from the Aiketik Group at the Western End of the South Tianshan Mountains of Chinaand Its Implications   总被引：1，自引：0，他引：1  

LI Yuejun  WANG Zhaoming  WU Haoruo  HUANG Zhibin  TAN Zejinand LUO Juncheng Institute of Geology  Geophysics  Chinese Academy of Sciences  Beijing Tarim Oil Field Company  PetroChin  Korl  Xinjiang Zhu Xiling 《《地质学报》英文版》2002,76(2):146-154

The Aiketik Group, distributed at the western end of the South Tianshan Mountains, China, is an important lithostratigraphic unit involved in the South Tianshan orogen. It is separated from the adjacent rocks by faults. Generally, the geologists ascribed it to the Upper Carboniferous according to Pseudostaffella sp., Profusulinella sp. and Fusulinella sp. found from the limestone and sandy limestone of Aiketik. Our radiolarian fossils were obtained from the chert samples collected from the Haladaok section located at the upper Tuoshihan River. The fossils mainly include Albaillella undulata Deflandre, Albaillella paradoxa Deflandre, Albaillella sp. aff. A. paradoxa Deflandre, Albaillella sp. cf. A. deflandrei Gourmelon, Albaillella sp., Albaillella excelsa Ishiga, Kito and Imoto (?), Belowea variabilis (Ormiston et Lane), Callella cf. C. parvispinosa Won, Entactinia cf. E. tortispina Ormiston et Lane, Entactinia aff. E. tortispina Ormiston et Lane, Entactinia variospina Won, Entactinia sp., Eostylodicty  相似文献   

塔里木盆地晚泥盆世及石炭纪岩相古地理   总被引：17，自引：4，他引：17       下载免费PDF全文

朱如凯  罗平  罗忠 《古地理学报》2002,4(1):13-24

塔里木盆地上泥盆统及石炭系包括5个组，自下而上分别为上泥盆统东河塘组和甘木里克组，石炭系巴楚组、卡拉沙依组和小海子组。其中东河塘组和甘木里克组地质时代为晚泥盆世，巴楚组地质时代为早石炭世杜内早中期，卡拉沙依组地质时代为晚杜内中期至巴什基尔期，小海子组地层时代为巴什基尔末期至莫斯科早期。岩石类型有碎屑岩和碳酸盐岩，还有膏盐岩，并夹薄层火山碎屑岩。沉积相主要为海陆过渡相组合，包括河流、三角洲、滨岸、浅海、碳酸盐岩台地、台地边缘6种相和12种亚相及33种微相。晚泥盆世东河塘期至石炭纪发生过4次较大的海侵，海侵范围由下而上逐渐增大，至晚石炭世小海子期海侵规模最大。东河塘期开始海侵，海水由西而东侵入，此时周缘碎屑物质供应充分，主要为无障壁海岸和障壁海岸沉积，西南缘为浅海相沉积。巴楚期晚期，海侵范围进一步扩大，物源向北或北东方向退却，陆源碎屑物质注入急剧减少，形成了一套富含生屑的碳酸盐岩地层，发育了开阔台地和局限台地亚相沉积。卡拉沙依期中期海侵规模比巴楚期更大，海水深度加大，西部为开阔台地亚相沉积，其余地区为局限台地亚相沉积。卡拉沙依期晚期和小海子期海侵达最大，向东扩展，大部分地区为开阔台地亚相沉积，东部地区为局限台地亚相沉积，塔北大部分地区缺失。  相似文献   

中国西北地区石炭纪岩相古地理?   总被引：8，自引：5，他引：8       下载免费PDF全文

郭宏莉  朱如凯  邵龙义  何东博  罗忠 《古地理学报》2002,4(1):25-35

根据研究区实测露头剖面沉积构造、岩矿、沉积地球化学、粒度分析、古流向资料、重矿物及沉积相的综合研究，结合地层、古生物、区域岩性资料等，对研究区石炭纪岩相古地理特征进行了分析。研究区早石炭世有5个古陆，即阿勒泰古陆南准噶尔古陆、敦煌-走廊古陆、阿拉善古陆、陇西古陆；有10个沉积相区，即库马苏滨浅海相区、布尔津-富蕴滨浅海相区、博格达滨浅海区、北准噶尔深海-半深海相区、北天山半深海-深海相区、克拉美丽冲积扇-湖泊相区、克拉玛依冲积扇-湖泊区、南天山-北祁连滨浅相区、柴达木碳酸盐台地相区、中祁连滨浅海相区。晚石炭世的岩相古地理与早石炭世相比，既有继承性，也有一定的差异，古陆范围有所小；有5个古陆，即阿勒泰古陆、北准噶尔古陆、马鬃山古陆、敦煌-阿拉善古陆、中天山古陆；有9个沉积相区，即库马苏河湖相区、布津-富蕴河湖相区、克拉美丽－巴里坤滨浅海相区、博乐－库尔勒－红柳园滨浅海相区、克拉玛依－哈密半深海－深海相区、乌鲁木齐生物滩丘区、柴达木碳酸盐岩台地相区、宗务隆山浅海-半深海相区、祁连滨浅海相区。半深海-深海相区、滨浅海相区和三角洲相区是较为有利的气分布区。  相似文献   

Early Carboniferous Radiolarian Fauna from Heiyingshan South of the Tianshan Mountains and Its Geotectonic Significance   总被引：5，自引：0，他引：5  

LIU YuInstitute of Geology  Chinese Academy of Geological Sciences  Baiwanzhuang Ro  Beijing 《《地质学报》英文版》2001,75(1):101-108

Abundant and well-preserved fossil radiolarians found from the Artencasher Formation, Heiyingshan of Baicheng County, Xinjiang Uygur Autonomous Region, are identified, including 15 species and 2 unnamed species in 9 genera. The fauna is dominated by the Family Entactiniidae of Spumellaria. According to the faunal characteristics, the radiolarians may be divided into five assemblages, namely, the Triaenosphaera sicarius, Entatinosphaera palimbola, Entactinia vulgaris, Belowea cf. variabilis and Archocyrtium sp assemblages. The fauna may be correlated with that from the Early Carboniferous of Frankenwald and Rein in Germany. Thus, ophiolite was formed in the Carboniferous, while the age of collision between the Ili plate and the Tarim plate is Early Carboniferous.  相似文献   

Dolomitization of the Waulsortian Limestone (Lower Carboniferous) in the Irish Midlands   总被引：1，自引：0，他引：1  

Jay M. Gregg  Kevin L. Shelton  Aaron W. Johnson  Ian D. Somerville  & Wayne R. Wright 《Sedimentology》2001,48(4):745-766

The Waulsortian Limestone (Lower Carboniferous) of the southern Irish Midlands is dolomitized pervasively over a much larger region than previous studies have documented. This study indicates a complex, multistage, multiple fluid history for regional dolomitization. Partially and completely dolomitized sections of Waulsortian Limestones are characterized by finely crystalline (0·01–0·3 mm) planar dolomite. Planar replacive dolomite is commonly followed by coarse (≥0·5 mm) nonplanar replacive dolomite, and pervasive void‐filling saddle dolomite cement is frequently associated with Zn–Pb mineralization. Planar dolomite has average δ¹⁸O and δ¹³C values (‰ PDB) of –4·8 and 3·9 respectively. These are lower oxygen and slightly higher carbon isotope values than averages for marine limestones in the Waulsortian (δ¹⁸O=–2·2, δ¹³C=3·7). Mean C and O isotope values of planar replacive dolomite are also distinct from those of nonplanar and saddle dolomite cement (–7·0 and 3·3; –7·4 and 2·4 respectively). Fluid inclusions indicate a complex history involving at least three chemically and thermally distinct fluids during dolomite cementation. The petrography and geochemistry of planar dolomites are consistent with an early diagenetic origin, possibly in equilibrium with modified Carboniferous sea water. Where the Waulsortian was exposed to hydrothermal fluids (70–280 °C), planar dolomite underwent a neomorphic recrystallization to a coarser crystalline, planar and nonplanar dolomite characterized by lower δ¹⁸O values. Void‐filling dolomite cement is isotopically similar to nonplanar, replacive dolomite and reflects a similar origin from hydrothermal fluids. This history of multiple stages of dolomitization is significantly more complex than earlier models proposed for the Irish Midlands and provides a framework upon which to test competing models of regional vs. localized fluid flow.  相似文献   

Carbonate-hosted siliceous crust type mineralization of Carnic Alps (Italy-Austria)     

Luciano Brigo  Gianfranco Camana  Franco Rodeghiero  Roberto Potenza   《Ore Geology Reviews》2001,17(4)

A carbonate-hosted stratabound siliceous crust type (SCT) mineralization (base metal sulphides, barite, fluorite) occurs over large areas of Carnic Alps and Karawanken in the Eastern Alps. It concerns a pervasively silicified lithological unit, up to some tens of metres thick, which caps the unconformity landscapes developed on epicontinental Devonian–Dinantian carbonates. The SCT mineralization is directly overlaid by different transgressive siliciclastic sediments, which range from Lower Carboniferous to Lower Permian. The presence of fragments of the SCT mineralization in the transgressive siliciclastic sediment bounds its whole lithological evolution within a short stratigraphic interval of Lower Carboniferous age. Selected features of the regional and lithostratigraphic setting are discussed. The chemical characterisation is based on the statistical evaluation of compositional data of 581 selected samples. Three significant groups of elements have been distinguished: (1) the hydrological and metasomatically active elements (Si, Ba, F), which show a strong negative correlation amongst themselves and characterise the silica-saturated aqueous solutions; (2) the terrigenous elements (Al₂O₃, K₂O, Fe_tot, TiO₂, B, Be, Ce, La, Nb, V, Y, Zr), which suggest a continental margin environment for silica deposition; (3) the sulphide metals (Cu, Pb, Zn, Ni, Sb, As, Hg, Cd), which define the metalliferous signature of the SCT mineralization.Some consistent, but still debatable genetic aspects of the SCT mineralization are as follow: (1) silica may be supplied by illitization of clay-rich basinal sediments during their diagenesis. δ¹⁸O of microcrystalline quartz ranges from +18.5‰ and +24.6‰ and is very similar to δ¹⁸O of authigenic quartz deriving from diagenetic processes of illitization of clay-rich basinal sequences. (2) The diagenetic evolution of these sediments may trigger off the movement of silica-rich marine pore waters. δ³⁴S of barite ranges from +15.5‰ to +19.3‰ with an average of +17.7‰ and are in good agreement with δ³⁴S of sulphate in ocean waters of Upper Devonian–Lower Carboniferous age. (3) A convective hydrological system, connected with sinsedimentary transtensive tectonics, active in the Carnic Alps since the Frasnian, may be the transport mechanism of aqueous solutions. (4) A weak drop in pH in the dominant carbonate environment represents the conditions for silica precipitation.SCT mineralization, showing persistent, independent and distinct characters, occurs over large areas also in other sites of the Alpine belt and outside Italy and Austria. Therefore, it points to important markers for some sedimentary sequences as well as to a worldwide significant cyclic metallogenic event. It represents a new ore deposit-type within the carbonate-hosted mineralization.  相似文献   

从岩相古地理论塔里木盆地西南地区石炭系油气潜景   总被引：3，自引：1，他引：3       下载免费PDF全文

牟中海  肖又军  王国林  唐勇  崔炳富 《地球学报》2001,22(1):79-84

石岩系是塔里木盆地西南地区重要的海相烃源岩和储集岩地层，油气潜力很大，但目前仅发现了1个气田、1个油田和2个油藏，勘探程度很低。本文在岩相古地理和地震地层学岩性岩相研究的基础上，对本区石炭系的烃源岩和储集岩的类型、分布及其与沉积环境的关系进行了研究，对盖层性质和分布，尤其对石炭系经过多次大的构造变动后所形成的油气潜景区进行了较深入的探讨，并指出4个有利的油气勘探地区，即巴楚隆起西端、玛扎塔克断裂带-海米-罗斯断裂带、麦盖提斜坡的北缘、南缘推覆体上盘。同时指出了各有利地区的勘探对策。  相似文献   

赤峰哈拉道口早石炭世花岗闪长岩年代学、地球化学及其地质意义     

李崴崴  陈井胜  高忠晖  刘淼  李斌  杨帆 《地质与资源》1992,29(3):212-223

  相似文献   

新疆巴里坤红井子地区石炭纪火山岩及其大地构造环境分析   总被引：7，自引：1，他引：7  

楼法生  唐春花 《新疆地质》1995,(1)

通过对红井子地区石炭纪人山岩岩石学、岩石化学、稀土元素、微量元素等特征分析；认为该区石炭纪火山岩具岛弧火山岩和裂谷火山岩两种不同属性，其形成构造环境也存在明显差异。该区火山岩分别形成于三个不同的构造环境，即准噶尔岛弧带、博格达裂谷带及喀尔力克岛弧带。  相似文献