银根-额济纳旗盆地恩格尔乌苏一带二叠系腕足类动物群及其意义

恩格尔乌苏处于哈萨克斯坦板块、塔里木板块与华北板块的结合部位,发育恩格尔乌苏断裂。恩格尔乌苏断裂的性质
和带内地层特征受到广大地质学家的关注。前人认为在恩格尔乌苏断裂带,地层主要是上石炭统阿木山组,形成构造混杂带,发
育蛇绿混杂岩,是塔里木板块和华北板块的分界。笔者在恩格尔乌苏北海尔汗剖面发现了腕足类动物群,该动物群属冷水和暖水
混生的“哲斯动物群”。据此,把前人认为是阿木山组中段的地层重新厘定为下-中二叠统双堡塘组。双堡塘组沉积环境为裂谷
环境下的三角洲-滨岸相,不是洋盆环境,暗示在早-中二叠世恩格尔乌苏断裂不是华北板块与塔里木板块的缝合带。      

论浙江北部晚二叠世Taihuella和Reichelina动物群及其地质意义

本文利用古生态研究方法对龙潭组的Taihuellafauna和长兴组的Reichelinafauna等动物群在壳体特征变异和演化阶段上进行了系统的研究与探讨，发现该动物群受地壳运动所造成古环境变迁和沉积岩相的变化所控制，阐述了浙北类在发展上的某些规律，为建立生物系统演化序列和地层沉积模式及准确地划分与对比地层等方面提供了依据。     

新疆柯坪地区奥陶纪印干组珊瑚化石的发现及意义

新疆柯坪地区印干组笔石及三叶虫化石丰富,已做过较多的工作,但珊瑚化石未见报道。柯坪地区南部柯坪塔格山一带出露完整的印干组,该组顶部首次发现富含珊瑚化石的厚层生物碎屑灰岩,珊瑚经鉴定计有9属14种（含未定种）。该珊瑚动物群中,Agetolites,Heliolites和Streptelasma最为丰富。根据珊瑚动物群特征、垂向变化规律及与邻区的对比,建立了Agetolites Heliolites Streptelasma生物组合。就生物组合特征而言,该组合可与浙赣地区三巨山组、准噶尔北部布龙果尔组对应,时代属晚奥陶世钱塘江早期,对应国际凯迪期晚期。就生物古地理特征而言,该动物群分子大部分见于华南地区,属中国南方的阿盖特珊瑚区,表明该区当时与华南相连。      

栾川出土的小窃蛋龙化石获“迷你豫龙”命名

近日,笔者获悉,栾川县出土的世界上最小的窃蛋龙化石获得了"迷你豫龙"的正式命名。栾川县位于伏牛山腹地,地处亚热带向暖温带的过渡区,属于典型的大陆季风型湿润、半湿润气候。上世纪70年代,在伏牛山地区的淅川、西峡、夏馆—高丘、五里川相继发现了大量的恐龙化石。近几年来,在栾川县境内的秋扒—潭头一带也发现了大量的伤齿龙、窃蛋龙、小型驰龙等恐龙化石。栾川的恐龙化石群是以小型兽脚类恐龙为主的动物群,已     

十万大山盆地恐龙化石价值分析

在区域地质调查中,在广西十万大山盆地南东缘下白垩统新隆组钙质粉砂质泥岩中发现恐龙骨骼化石。化石保存良好,骨松质层清晰可见,经初步鉴定为白垩纪时代恐龙的骨骼化石。进一步发掘研究化石,对研究广西早白垩世恐龙动物群及生态环境、十万大山盆地发展演化和发展旅游地质产业有重要意义。     

豫西巩义地区上石炭统本溪组泥岩地球化学和富锂特征及其控制因素

泥岩的沉积序列和地球化学特征包含大量地质信息,广泛应用于沉积学及其物源分析等。豫西巩义地区上石炭统本溪组富集锂资源,但对于锂资源的来源、沉积条件等控制因素及赋存的矿物等不明确。基于野外露头等资料,综合分析豫西巩义地区上石炭统本溪组主量、微量和稀土元素特征,阐明本溪组锂富集特征,探讨本溪组的源岩、岩石风化程度、沉积物分选状况和古环境特征,进而分析本溪组锂富集的成因。结果表明：本溪组锂资源丰富,主要富集在泥岩中(Li平均质量分数为1 487×10^-6),而铝土矿Li含量较低;沉积序列表明,本溪组主要以细粒沉积物为主,形成于潟湖环境;B/Ga、Sr/Cu值等参数表明沉积时期海水为微咸水,气候条件为温湿—干热气候,处于还原环境;微量和稀土元素等综合图解分析表明,物源区母岩以长英质岩浆岩为主,灰岩和泥岩等是次要物源,化学蚀变指数、风化指数参数及图解表明源岩遭受强烈的风化作用,经历沉积再旋回作用。本溪组富锂泥岩的物源、沉积特征等综合分析表明,锂资源的富集与泥岩中高岭石、绿泥石等黏土矿物关系密切,本溪组源岩为锂富集提供物质基础,沉积物的再旋回过程、沉积环境等沉积特征影响锂资源的...     

黔南克脚二叠纪末生物群特征及其地质意义

贵州惠水克脚剖面是南盘江盆地北缘二叠系-三叠系界线剖面,地层连续,产不同门类的化石,对古生代-中生代之交黔南古地理和生物演化研究具有重要意义。剖面主要包括上二叠统大隆组和下三叠统大冶组下部。大隆组岩性主要为硅质泥岩、钙质泥岩和炭质页岩,夹火山灰黏土岩与薄层硅质灰岩,泥岩发育水平层理。大隆组主要产游泳生物菊石、浮游生物放射虫,另外产小个体腕足类、双壳类和腹足类等,少数层位含植物化石。大冶组下部主要为薄层泥质灰岩夹钙质泥岩。通过岩性、古生物组合、沉积构造等分析,认为本剖面在二叠纪末为离古陆较近的深水沉积。      

从叶肢介化石讨论田师傅东营坊组的时代

辽东本溪田师傅和新开岭地区出露的一套沉积碎屑岩,范国清(1982年)称为东营坊组,时代隶属晚侏罗世。本文依据 Euestheria ziliujinensis 群将东营坊组时代置于中侏罗早中期,与辽西海房沟组、冀北九龙山组叶肢介动物群主体基本一致。依据 Pagiophyllum cf.maculosum,P.cf.shahoziensis,Brachyphyllumcf.mamillare,Coniopteris sp.等植物化石和区域地层接触关系,东营坊组应置于转山子组、大堡组和三个岭组之上。     

海南玉带滩障壁型海岸现代沉积特征及沉积演化

海南玉带滩是我国南海沿岸典型的障壁型海岸现代沉积场所之一。根据野外考察和室内分析,从沉积物的成分、结构、沉积构造等方面揭示了玉带滩障壁型海岸现代沉积特征。结果表明：玉带滩东侧为障壁岛海滩,沉积层序总体上表现为粒度向上变粗;中部为障壁岛沙丘,以中、粗粒石英砂为主,具平行层理、斜层理;西侧为障壁坪,以中、细砂沉积为主,夹杂一些贝壳碎片,层理构造比较明显。玉带滩西侧水体为河流作用明显强于潮汐作用的潟湖;河口沙坝发育或河流岩岛阻挡产生河汊是形成潟湖中冲积岛分布的主要原因;仅在潮汐通道外侧出现拦口沙坝堆积。现代沉积特征结合Google Earth卫星图像分析认为,该障壁型海岸沉积演化大致包括3个阶段：第一阶段,河流携带泥沙入海,在河口湾地区形成多级近新月型河口沙坝。第二阶段,由于后期水道延伸方向、水动力的不断变化,西侧河口沙坝出现合并并向冲积岛转化;在海岸拐弯处,以原有河口沙坝为主体,形成初期障壁沙坝,障壁沙坝西侧水体演变成潟湖。第三阶段,障壁岛西侧受河流冲刷作用影响,河口沙坝坝头几乎完全消失;障壁沙坝形成后,潟湖水面加宽,流速减小,河口沙坝增生合并,最终形成了三大冲积岛(沙坡岛、东屿岛、鸳鸯岛...     

中期旋回格架沉积演化规律及其对渗透率差异的影响——以伊拉克M油田Asmari组A段为例

伊拉克M油田新近系Asmari组A段是以白云岩为主的孔隙型碳酸盐岩储层,储层较强的非均质性制约油田的高效开发。基于岩心、薄片、测井、阴极发光和物性等资料,研究Asmari组A段中期旋回格架内沉积演化规律及其对渗透率差异的影响。结果表明:M油田Asmari组A段沉积相主要为半局限台地相,沉积亚相以台内滩和潟湖为主;中期旋回适用于以台内滩为主的沉积体系;基于中期旋回界面,可划分为MSC1、MSC2和MSC3三期中期旋回。研究区处于长期旋回基准面下降半旋回早期,随长期旋回基准面的下降,中期旋回内沉积环境逐渐局限,沉积亚相由台内滩逐渐过渡为潟湖;纵向上,低渗—中渗段所占比例减少,特低渗段所占比例逐渐增多,表明中期旋回和长期旋回影响渗透率差异。该结果为优化M油田的新井地质设计提供参考。     

辽东苏子河盆地叶肢介化石

本文描述的叶肢介化石是采自辽东中生代苏子河盆地的小岭组、梨树沟组和聂尔库组。小岭组产Eosestheria(Allestheria);梨树沟组产Yanjiestheria;聂尔库组产Orthestheria,Orthestheriopsis。Yanjiestheria,Neodiestheria。梨树沟组、聂尔库组所产化石为典型的延吉叶肢介群分子,属旱白垩世当无疑议。小岭组的时代从伴生的其它门类化石看亦归属早白垩世为宜。苏子河盆地所产叶肢介为延吉叶肢介群,故梨树沟组、聂尔库组与辽西九佛堂组和阜新组不能对比,这是因为辽西九佛堂组所产叶肢介为东方叶肢介群,其层位应在延吉叶肢介群之下。     

Age of Berh Hairhan Formation of Mongolia dated by conodonts

Conodont Caudicriodus angustus angustus(Steward et al.,1956) and Caudicriodus angustus cauda(Wang et al.,2005) were found from a big limestone lens of the Berh Hairhan Formation in the place of W 150 km to Ulaanbaatar City.The discovery indicates that the Berh Haihan Formation should be assigned to Middle Devonian Eifelian Stage.This conodont fauna was from a shallow cooler water facies in the relatively high latitude.     

Age of Berh Hairhan Formation of Mongolia dated by conodonts

Conodont Caudicriodus angustus angustus(Steward et al.,1956)and Caudicriodus angustus cauda(Wang et al.,2005)were found from a big limestone lens of the Berh Hairhan Formation in the place of W 150 km to Ulaanbaatar City.The discovery indicates that the Berh Haihan Formation should be assigned to Middle Devonian Eifelian Stage.This conodont fauna was from a shallow cooler water facies in the relatively high latitude.     

莺歌海盆地中新统海相烃源岩发育主控因素及模式

中新统海相烃源岩是中国近海莺歌海盆地主要油气供给层段，也是我国新生代海相烃源岩的典型代表。综合利用地质、地球化学和古生物等资料，在烃源岩有机地球化学特征分析的基础上，探讨了莺歌海盆地中新统海相烃源岩发育的主控因素，并建立了相应的形成模式。结果表明，莺歌海盆地发育中等-好级别的中新统海相烃源岩，并具有较强的横向与纵向非均质性；中新统海相烃源岩受古气候、古生产力、水介质条件、沉积速率及海平面变化等因素的综合影响，发育以莺东斜坡带梅山组、三亚组为代表的海相陆源型和以东方区、乐东区梅山组为代表的海相内源型2种模式，其中以海相内源型烃源岩生烃条件最为优越。      

陕西南郑福成奥陶系－志留系界线的笔石

通过对南郑福成奥陶系－志留系界线的笔石组合和笔石体形态等的研究，再次论证了奥陶系与志留系界线以划在Ｇ·ｐｅｒｓｃｕｌｐｔｕｓ带之底为宜，并对界线附近的部分重要和特征笔石进行了描述。     

The Cretaceous of the Eastern Bangong-Nujiang Suture Zone (Tibet):Tectono-Sedimentation

The ophiolite-bearing Bangong-Nujiang zone (BNZ) traversing central Tibet from east to west separates the Qiangtang block in the north from the Lhasa block in the south. The Cretaceous of the area includes Chuanba Formation (K1c), Duoba Formation (K1d), Langshan Formation (K1l) and Jiangba Formation (K2j). The K1c is composed of black shale,sandy pelite, siltstone, sandstone, coal beds and volcanic rocks, of shallow marine facies. The K1d consists of terrestrial siliciclastics intercalated with some calcareous sandstone beds bearing Orbitolina sp. indicating marine influence. The K1j is carbonate platform deposits of shallow marine and lagoon. The K2j is characterized by terrestrial thick massive red conglomerate. An active margin related to B-subduction zone is considered to be the geological setting of the Cretaceous sedimentation.     

The Cretaceous of the Eastern Bangong-Nujiang Suture Zone (Tibet):Tectono-Sedimentation

1IntroductionThe Tibet plateau consists of terranes which were accreted in a southward-younging succession from Late Permian to Mid-Eocene (Dewey etal., 1988; Mattern etal., 1998; Mattern and Schneider, 2000). The Songpan-Ganzi terrane was accreted to the Kunlun during Late Permian along Kunlun-Qin-ling suture. The Qiangtang block was added onto the Songpan-Ganzi terrane at the Jinsha suture dur-ing Late Triassic-Early Jurassic. The Lhasa block became attached to the Qia…     

Geochemical characteristics and sedimentary environment significance of carbonate rocks in Nanfen Formation of Qingbaikou System in Tonghua,Jilin Province

In order to reveal the sedimentary environment of carbonate rocks in Nanfen Formation of Qingbaikou System in Tonghua, Jilin Province, the mineral composition and petrochemistry of carbonate rocks in Nanfen Formation were analyzed. The mineral compositions of five carbonate rock samples in Nanfen Formation mainly consist of calcite, with minor clay minerals and quartz, and the rock type is siliceous marlite. The Mn/Sr va-lues range from 1.52 to 4.08, with an average of 2.64, indicating that the carbonate rocks experienced weak diagenesis; the Sr/Ba values range from 1.26 to 2.51, with an average of 1.93, indicating marine environment; the ratio of Mg/Al ranges from 35.33 to 86.34, with an average of 62.95, indicating the seawater environment, which is consistent with the result from Sr/Ba; the MgO/CaO values range from 0.01 to 0.04, with an average of 0.02, indicating humid environment; the values of V/(V+Ni) range from 0.63 to 0.73, with an average of 0.70, indicating anoxic environment. In summary, geochemical analyses show that the Nanfen Formation carbonate rocks are marine deposits, in a warm, humid, anoxic environment with poor flow of seawater, and subsequently underwent weak diagenetic alteration.     

琼东南盆地梅山组泥岩盖层封闭性综合评价

通过单井资料统计和沉积相研究,对琼东南盆地梅山组泥岩盖层进行宏观评价,认为盖层岩性以浅海—半深海相泥岩为主,主要发育于北部隆起带与中央坳陷带,侧向连续性好。其最大单层厚度、累积厚度以及含砂量等宏观参数显示,优质泥岩呈现沿北西—南东方向展布的特征。利用测井声波时差和实测岩石样本排替压力之间的关系,计算三亚组一段砂岩和梅山组泥岩的排替压力差,并进行微观评价,认为单井上排替压力差呈凸起高、凹陷低的特点。选取岩性、沉积环境、最大单层厚度、累积厚度、含砂量以及储层与盖层排替压力差作为参数,分别赋予相应的权值和权重,对泥岩盖层封闭性进行综合评价,认为梅山组泥岩盖层综合品质呈规律性变化,表现为北部坳陷低、中部隆起和中央坳陷高的特点,对三亚组发育于北部隆起带周缘的滨海相砂体和发育于中央坳陷带附近的浊积砂体起到了良好的封盖作用。     

Biostratigraphy of Asmari Formation in Ghare Agha seyed of Farsan region,Chaharmahale Bakhtiari Province,Iran

The Asmari Formation consists of shallow marine sedimentary rocks deposited on ramp setting .Lar-ger benthic foraminifera collected from Asmri Formation are dominated by hyaline and porcelanouse forms , in-cluding Amphistegina, Nummulites, Archaias, Astrotrillina, Miogypsinella, Miogypsinoides, Lepidocyclina, Operculina, Spiroclypeous and Miliolids.The presence of Nummulites cf.vascus in the lower part of the forma-tion allows the age to be determined as Rupelian .The occurrence of Borelis pygmae is an index taxon of the Ru-pelian-Chattian and indicates Early Chattian of SBZ 21-22 in the study section .The first appearance of Mio-gypsinella akadagensis shows Late Chattian ( SBZ 23) and defines the upper boundary of the SBZ 21-22.The new data are the first evidences showing that the shallow marine Asmari Formation is attributed to Oligocene (Rupelian-Chattian) age for this region.