浙江桐庐阳新统栖霞组的(竹蜓)类化石及多重地层划分     

颜铁增  朱朝晖  卢成忠  许兴苗 《地层学杂志》2007,31(1):79-89

浙江桐庐栖霞组可划分为二个(竹蜓)带:上部为Cancellina neoschwagerinoides-Verbeekina grabaui带,归属祥播阶;下部为Misellina claudiae带,归属罗甸阶.栖霞组被划分出3个正层序和6个四级层序.高频旋回层研究表明:栖霞组主要的成岩环境有台地相、浅海陆棚相和盆地相三种类型,从下至上总体反映为台地向盆地的演化环境.  相似文献   

东昆仑西段祁漫塔格群早志留世笔石化石的发现   总被引：5，自引：1，他引：5  

黎敦朋  樊晶等 《地质通报》2002,21(3):136-139

首次在东昆仑西段祁漫塔格山白干湖地区原划奥陶系祁漫塔格群浊积岩下部层位中发现Monoclimacisgriestoniensis(Nicol),Monograptuspriodon(Bronn),Monograptussp.,Streptograptuscf.becki(Barrande),Torngni-graptuscf.arcuatus(Barrade)早志留世笔石化石组合,表明祁漫塔格群除有奥陶纪地层外,还包含有早志留世地层。  相似文献   

笔石组成与结构的微区分析   总被引：4，自引：0，他引：4  

刘大锰  侯孝强 《矿物学报》1996,16(1):53-57

采用显微傅立叶红外光谱（Micro－FT－IR）和装有液体金属离子枪的高分辨飞行时间二次离子质谱仪（TOF－SIMS）首次研究了笔石的化学组成与结构。Micro－FT－IR谱图在1680～1740cm－1和1000～1320cm－1范围内吸收强度高，而1600cm－1处吸收强度低．表明笔石是由含N、O等杂质原子基团的高分子聚合物组成，且该笔石热演化程度不高；TOF－SIMS谱图表明，笔石的二次离子峰主要集中在较低质量数处，在高质量数峰强度低，且M／Z43，105，135等峰强度高，亦证实笔石的上述组成特点。研究结果表明Micro－FT－IR和TOF－SIMS技术是煤及源岩显微组分微区成分分析的有力工具。  相似文献   

湖北宜昌和南漳奥陶系大湾组笔石生物地层   总被引：4，自引：4，他引：0  

骆天天  张元动 《地层学杂志》2008,32(3)

根据宜昌陈家河剖面大湾组的笔石标本,确立笔石序列自下而上为:Didymograptellus eobifidus带、Corymbograptus deflexus带和Azygograptus suecicus带(大湾组下段),Exigraptus clavus带和Undulogr aptusaustrodentatus带(大湾组上段)。对湖北南漳的全家湾和李家湾两剖面的大湾组进行了详细采集测量,其中全家湾剖面大湾组下段自下而上识别出D.eobifidus带、C.deflexus带和A.suecicus带;李家湾剖面大湾组下段自下而上识别出D.eobifidus带和A.suecicus带,证实南漳大湾组的底界与宜昌地区基本一致。  相似文献   

新疆西北部早古生代地层   总被引：7，自引：2，他引：5  

陈旭  林焕令 《地层学杂志》1998,22(4):241-251

根据新疆西北部伊宁果子沟、艾比湖及和布克赛尔等地的早古生代地层剖面,对这一地区寒武系、奥陶系和志留系的岩石地层单元和生物带作了修订,特别是重新修订了奥陶系的新二台组和风沟组,并建议取消塔勒基河组。对下古生界各系的生物带作了较大的修订,并基于此对各纪地层作了划分和对比。根据地层的发育特征和各门类生物地理分布,认为新疆西北部在早古生代属于哈萨克斯坦古板块的东延部分。  相似文献   

江西修水流域上奥陶统五峰组的笔石分带     

曹奇原  王海峰 《高校地质学报》1998,4(3):318-323

重新研究了江西武宁官塘源五峰期地层剖面,将原五峰组和原新开岭组合二为一称为五峰组,并对五峰组的笔石带进行了修订：取消Paraorthograptus uniformis带,改称Dicellograptus szechuanensis带为Dicellograptus complexus带。修订后的笔石序列自下而上是：Dicellograptus complexus带、Tangyagraptus typicus带和Diceratograptus nurus带  相似文献   

滇西南耿马弄巴地区南皮河组层型剖面地层层序、时代的重新认识   总被引：4，自引：0，他引：4  

段向东  张志斌  冯庆来  王伟  李宗亮  杨仕潘  张凡 《地层学杂志》2003,27(1):59-65

对前人建立的上二叠统南皮河组的层型剖面——弄巴剖面进行了详细研究 ,发现该地层属于一套被动大陆边缘浊积岩为主的沉积岩系 ,可概括为四种层序类型特征 :一为代表浊流沉积的鲍马序列 ;二为由泥质岩与岩屑石英 (杂 )砂岩透镜体 (层 )构成的水道沉积序列 ;三为由薄层状砂岩与泥岩呈韵律状互层构成的浊流远端低密度流序列 ;四为薄层状硅质岩与硅质泥岩呈韵律状组成的基本层序。该组中采获了低等蕨类植物、牙形石和笔石等化石 ,证实其时代属于早泥盆世—晚泥盆世。根据该地层的岩性组合、沉积环境等特征及区域对比 ,应归于泥盆系温泉组。  相似文献   

扬子区西南缘奥陶纪末—志留纪初笔石生物地层对比及意义          下载免费PDF全文

张娣  刘伟  周业鑫  牟必鑫  周志  郝景宇  赵安坤  陆俊泽  余谦 《沉积与特提斯地质》2022,42(3):413-425

利用扬子西南缘天全、汉源、甘洛、布拖、金阳、永善、绥江、大关地区五峰组—龙马溪组重点剖面露头点和钻井岩心资料,通过笔石生物地层划分,建立了五峰组—龙马溪组黑色页岩的等时地层格架。通过对比纵横向黑色页岩的TOC含量、沉积厚度、优质页岩厚度等数据变化,探讨笔石带的分布与沉积环境、优质页岩的关系。结果表明,各剖面和钻井中WF2—LM4笔石带优质页岩普遍发育。其中布拖、金阳靠近康滇古陆边缘的地区,LM5笔石带、LM6笔石带岩石地层明显增厚;永善—绥江云永地2井、新地2井、绥江B井等地区,笔石带分布和沉积环境相似,优质页岩沉积上界由LM4笔石带逐步上延至LM6笔石带。五峰组—龙马溪组优质页岩在靠近康滇古陆一侧沉积时限为WF2—LM4及以下笔石带,远离古陆一侧沉积时限呈逐渐变长的趋势。天全大井坪、汉源轿顶山一带WF2—LM5笔石带优质页岩发育,轿顶山地区岩石地层厚度明显减薄,天全大井坪地区明显增厚,受特殊环境影响可能仍具有良好的勘探潜力。研究成果对扬子西南缘页岩气沉积有利区优选提供了依据。  相似文献   

Diversity history of Ordovician graptolites and its relationship with environmental change     

Zhang YuanDong  Chen Xu 《中国科学D辑(英文版)》2008,51(2):161-171

Statistical analysis based on global data indicated that the planktonic graptolites presented a distinguished pattern from that of benthic communities during the great Ordovician biodiversification. The graptolites started to diversify from the beginning of Ordovician and reached an acme in the early Middle Ordovician, but subsequently underwent a steady decline to the end of Ordovician. During the Ordovician, many clades of the graptolites made their originations, flourishing and replacements. However, in different regions and distinct environments across the world, graptolites may presumably display distinct patterns of radiation and evolution, a hypothesis to be tested. Herein a study of the graptolite diversity in the Early to Middle Ordovician in the Upper Yangtze Region (Platform) and Jiangnan Region (Slope), South China, is conducted. The results indicate that graptolites underwent a remarkable increase in both regions, but with distinct magnitude, scope, process and patterns. The diversification of graptolites in the Upper Yangtze Region, though less prominent, is divided into four stages and includes two peaks. In the Jiangnan Region, the graptolite diversification is far more prominent and includes three stages and one peak. Based on the distinct diversity histories and composition of graptolites in the two representative regions, a 'deep-water origin and shallow-water dispersal' model is proposed for the Ordovician graptolite faunas. According to the model, the major graptolite faunas of Ordovician originated in the deep-water region on the continental slope, the source of the graptolite novelties, and subsequently spread into shallow-water region on the shelf. Besides, we also conduct a comparison study of the Ordovician graptolite diversity in South China and other major regions. The results display that the graptolites diversified globally in the Early and Middle Ordovician. At the beginning of Ordovician, graptolites underwent a significant ecological innovation of graptolites: planktonic forms were derived from their benthic ancestors. This derivation resulted in the great guild expansion of graptolites. In late Early Ordovician (Floian), the global expansion of graptolites commenced. From the Floian to the end of Middle Ordovician, the graptolites diversity increased remarkably and displayed three peaks for all the regions. However, the peaks are somewhat distinct in magnitude and timing among regions. The Darriwilian peak is prominent in both South China and Baltic region, but inconspicuous in Australasia. No close relationship between the graptolite diversification and the palaeolatitudes are supported herein. Instead, the graptolite diversification seems to coincide with the global sea-level rises, suggesting a possible intrinsic relationship between them.  相似文献   

The Most Complete Sequence of Telychian Graptolite Zones in the World   总被引：1，自引：0，他引：1  

FU Lipu  ZHANG ZifuXi ''an Institute of Geology  Mineral Resources  Xi ''an  Shaanxiand GENG LiangyuNanjing Institute of Geology  Palaeontology  Chinese Academy of Sciences  Nanjing  Jiangsu 《《地质学报》英文版》2000,74(2):126-131

This paper divides the Telychian into 7 graptolite zones, 12 subzones and 4 chitinoans in the Ziyangregion, China. The zones and subzones of England are almost totally suitable for the case of Ziyang in China, though they are 10000 km apart. All the above-mentioned biozones are found only in a unitary continuous section in Ziyang. It has been proved that the Ziyang section is the one with the most complete sequence of Telychian graptolite biozones in the world.  相似文献