湖北宜昌陈家河下奥陶统分乡组和红花园组的几丁虫序列

系统介绍湖北宜昌陈家河剖面下奥陶统分乡组和红花园组的几丁虫分布发育特征,将分乡组和红花园组的几丁虫自下而上划分为Lagenochitina destombesi带和Euconochitina symmetrica带,阐述了几丁虫组合特征,并与国外同期几丁虫生物带进行了对比。     

重庆城口廖子口奥陶系庙坡组的几丁虫

系统介绍城口廖子口奥陶系庙坡组几丁虫分布、发育特征及其与笔石生物带的关系 ,讨论了几丁虫的地层意义 ,并与国外典型地区同期地层的几丁虫进行了对比。城口廖子口庙坡组几丁虫的组合特征虽然与波罗的海地区、加拿大纽芬兰和魁北克地区同期地层的几丁虫存在一定的相似性 ,但总体上具有分布广、地质延限长、生物地理分区不明显的特点     

湖北宜昌和南漳奥陶系大湾组笔石生物地层

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。     

安徽省黄山地区唐家坞组生物地层

安徽省南部黄山市刘村一带唐家坞组的时代以往归为晚志留世,新近在唐家坞组中采获腕足类、瓣鳃类、腹足类等多门类化石,并首次采获胞石、鹦鹉螺等化石,其中胞石Conochitina(Densichitana)dens的时代为兰多维列世末至文洛克世初期,含这些化石的层位相当于秀山动物群的层位。结合地质情况分析,唐家坞组时限主要属于早志留世。     

湖北宜昌黄花场中/下奥陶统界线附近几丁虫组合及其地层学意义

对宜昌黄花场大湾组下段牙形石 Oepikodus evae带至 Baltoniodus triangularis带系统采集与分析几丁虫样品 ,共发现几丁虫 6属 12种 ,其中包括 1个相似种、1个未定种 ,它们是 Conochitina raymondii,C.ordinaria,C.primitiva,C.langei,C.brevis,C.poumoti,C.decipiens,Belonechitina cf.micracantha,L agenochitina esthoni-ca,L.sp.,Eremochitina baculata和 Cyathochitina dispar等。根据上述几丁虫的地质和地理分布特征 ,自下而上可划分为 Conochitina langei带和 Eremochitina baculata带 ,讨论并指出了他们与相关笔石、牙形石生物带的关系     

湖北长阳花桥下奥陶统几丁虫

本文介绍了湖北长阳花桥下奥陶统几丁虫的分布发育规律,讨论了几丁虫的地质意义,并与国内外同期地层作了对比,指出了该几丁虫动物群生物古地理的亲缘关系,并对部分几丁虫种进行了拟定与描述．     

滇西南早泥盆世地层研究新进展

滇西南西盟里拉、孟连回库腊垒组发现早泥盆世Ｍｏｎｏｇｒａｐｔｕｓｈｅｒｃｙｎｉｃｕｓ、Ｍ．ｆａｌｃａｒｉｕｓ等７个笔石种,从下到上识别出Ｍ．ｕｎｉｆｏｒｍｉｓ带、Ｍ．ｈｅｒｃｙｎｉｃｕｓ带和Ｍ．ｆａｌｃａｒｉｕｓ带３个笔石带,分别属于洛赫科夫期早期、晚期和布拉格期早期,并与国内外其他地区的笔石带进行了对比。对该时期笔石的生物地理分析表明,洛赫科夫期的笔石具有全球性,而布拉格期的笔石则显示出一定程度的地区性。     

New chitinozoans from the historical type area of the Hirnantian Stage and additional key sections in the Wye Valley,Wales, UK

The type locality for several core elements of the Hirnantia brachiopod fauna is a small disused quarry on the western slopes of Cwm Hirnant. There, the Hirnant Limestone Member of the Foel‐y‐Ddinas Mudstone Formation yields a new, well‐preserved chitinozoan assemblage, attributed to the Spinachitina taugourdeaui Biozone. This allows tight correlation with the Hirnantian of Baltica and Laurentia and neatly ties the chitinozoan zonation with the classical brachiopod fauna. Nearby, the chitinozoan assemblage from the Caradoc Cymerig Limestone Member at Gelli‐grîn belongs to the Spinachitina cervicornis Biozone?, and is identical to that recovered from the Burrellian in the Onny Valley, Welsh Borderland. A Silurian assemblage higher up section, discovered in the Cwm‐yr‐Aethnen Formation, is attributed to the globally recognized Eisenackitina dolioliformis Biozone. Attempts to integrate the chitinozoan and graptolite biozonation, in the central Welsh Rhayader area, were less successful. Copyright © 2008 John Wiley & Sons, Ltd.     

湖北宜昌志留系纱帽组几丁虫生物地层学

调查分析了湖北宜昌龚家冲志留系纱帽组剖面156件样品,在其中95件泥岩、粉砂岩样品中发现大量保存精美的早志留世几丁虫化石。自下而上识别出Conochitina malleus,Plectochitina pseudoaggltinans,Eisenackitinadolioliformis,Eisenackitina causiata等生物带。每一个几丁虫生物带均代表一次几丁虫多样性发展,由新生分子和已知分子所构成的组合特征能很好地与拉脱维亚、爱沙尼亚和沙特阿拉伯等国外同期地层的几丁虫组合进行对比。宜昌地区志留系几丁虫生物带与笔石、牙形石带的关系显示宜昌地区纱帽组的地质延限大致与笔石Stimulograptus sedgwickii带至Oktavites spiralis带相当,特列奇阶底界位于纱帽组第二段底部,与几丁虫Plectochitina pseudoagglutinans生物带的底界位置接近。同期地层,在重庆涪陵焦石坝等地为产大量笔石的富有机质页岩,是页岩气的重要储层,因此,这一研究成果对于深入认识我国南方志留系页岩气储层的分布发育特点具有重要意义。     

A palynological biozonation for the Maastrichtian Stage (Upper Cretaceous) of South Carolina, USA

Three palynological biozones are proposed for the Maastrichtian Stage of South Carolina. In ascending stratigraphic order, the biozones are the Carolinapollis triangularis (Ct) Interval Biozone, the Holkopollenites chemardensis (Hc) Interval Biozone, and the Sparganiaceaepollenites uniformis (Su) Interval Biozone. Integration of the biostratigraphy with lithologic and geophysical log data suggests that within the study area, the upper and lower boundaries of each zone are bounded by regional unconformities, and that a three-fold subdivision of the Maastrichtian Stage is warranted. The biozonation is based on the analysis of 114 samples from 24 subsurface and three outcrop sections from the Coastal Plain of South Carolina; samples from an additional seven subsurface and 18 outcrop sections from North Carolina and Georgia were examined to evaluate the geographic extent of the biozones. One new genus and five new species of pollen are described, and emendations are presented for two genera and one species of pollen.     

A proposed GSSP for the base of the Middle Ordovician Series： the Huanghuachang section,Yichang, China

The Huanghuachang section near Yichang, southern China meets the requirements of Global Stratotype Section and Point (GSSP) for the base of the Middle Ordovician Series and the yet-to-be-named third stage of the Ordovician System (or lower stage of Middle Ordovician Series). The conodont succession at the section is complete across the Lower to Middle Ordovician series boundary and several excellent phylogenetic lineages of Baltoniodus, Trapezognathus, Periodon, and Microzarkodina are represented. The definition of the base of the Middle Ordovician is proposed to be the first appearance datum (FAD) of Baltoniodus? triangularis in the section. It is followed closely by the FAD of Microzarkodina flabellum, which is taken as a reasonable proxy for the boundary. This level approximates the boundary between the lower and upper intervals of the Azygograptus suecicus graptolite Biozone, and nearly coincides with the base of the Belonechitina henryi chitinozoan Biozone.The proposed GSSP for the base of the international Middle Ordovician Series is located in a roadside exposure at the base of Bed (SHod) 16, 10.57 m above the base of the Dawan Formation in the measured Huanghuachang section near Yichang City, southern China. The same faunal succession is also recorded from the Chenjiahe (formerly Daping) section, 5 km to the north of the Huanghuachang section. The proposed boundary horizon can be recognized and correlated globally with high precision in both relatively shallow-water carbonate facies as well as in deep-water graptolite facies.     

浙江临安板桥奥陶系胡乐组笔石新材料及其意义

报道在浙江临安板桥奥陶系剖面的胡乐组中发现的较丰富的笔石动物群,包括Pterograptus elegans,Expansograptus sp.1,Tylograptus sp.,Cryptograptus?sp.,Archicli macograptus angulatus,A.caelatus,Procli-macograptus angustatus等主要属种,应属达瑞威尔阶Pterograptus elegans笔石带。这一发现表明,临安板桥一带的胡乐组时代跨度非常局限,底界比浙赣交界"三山地区"的胡乐组之底高2个笔石带,顶界对比则低2个笔石带。其下伏牯牛潭组的顶界与宜昌三峡地区相比,也低了2个笔石带,具明显的穿时现象。     

黔北红花园下奥陶统湄潭组的几丁虫化石及其地层意义

1983年初笔者在贵州桐梓红花园奥陶系剖面进行了系统采样,经室内分析处理,在下奥陶湄潭组获得丰富的几丁虫化石,在所处理的15块样品中,有9块样品含有几丁虫化石,其中4块样品几丁虫化石丰富,大部分保存完好,未变形。     

云南墨江志留纪地层及其笔石序列

云南墨江志留纪地层从下到上包括漫波组和水箐组。根据在水箐组中发现的大量笔石,从下到上共识别出Colonograptuspraedeubeli带、C.ludensis带、Lobograptusprogenitor带、L.scanicus带和Saetograptusfritschilinearis带等5个笔石带,并将各带与捷克、中亚、加拿大和我国广西等地的相应笔石带进行了详细对比。研究表明水箐组的时代应属文洛克世晚期—罗德洛世中期,其层位应在文洛克世早期的漫波组之上。     

江苏南部Z-8井高家边组胞石生物地层

通过对Ｚ－８井志留系高家边组地层中胞石的研究,共鉴定３属８种,从上到下共确立了Ｃｏｎｏｃｈｉｔｉｎａｔｒｕｎｃａｔａ带、Ｃ．ｒｏｓｉｃａ带和Ｂｕｒｓａｃｈｉｔｉｎａｒｅｃｔａｎｇｕｌａｒｉｓ带３个胞石带,进行了地层对比,并指出Ｃ．ｒｏｓｓｉｃａ带在本区高家边组地层中是首次发现。     

Ordovician successions in southern-central Xizang (Tibet), China—Refining the stratigraphy of the Himalayan and Lhasa terranes

The Ordovician stratigraphy of southern-central Xizang (Tibet) has been revised based on new conodont data recovered from 43 samples in four stratigraphic units and their integration with existing nautiloid and graptolite data. The Histiodella holodentata and Pygodus serra biozones have been identified respectively in the Alai and Jiaqu formations of the Chiatsun Group exposed near Alai village in Nyalam County within the Himalayan terrane, and the Yangtzeplacognathus foliaceus Subbiozone (lower part of the Pygodus serra Biozone) in the Sangqu Formation exposed at the Guyu section within Zayu County in the Lhasa terrane. Recognition of these biozones has increased the precision of correlation of the middle-upper Darriwilian strata in the region. Regional reassessment of the Ordovician stratigraphy permitted by new biostratigraphic data has allowed revised definitions for the Chiatsun and Keerduo groups and the Sangqu and Xainza formations. The Chiatsun Group is defined herein to include three lithologically distinctive formations in descending order, the Jiaqu, the Alai and the Adang formations. The stratigraphic age for the Jiaqu and Alai formations in the type area ranges from the middle Darriwilian (Histiodella holodentata Biozone) to middle Katian (Hamarodus brevirameus Biozone), but the age of the Adang Formation remains less certain.     

论海南岛地区志留系

海南岛志留系以往被划分为上、中、下三个统。志留系之上是南好组 ,其层位以往被确定为下石炭统岩关阶 ,并认为它与其下的上志留统足赛岭组呈不整合接触。最近在南好组选层型剖面发现早志留世特里奇期晚期(L ate Telychian)的 Xinanospirifer腕足动物群和三叶虫 L atiproetus cf.latilimbatus (Grabau) ,重新论证了以往被确认为中志留统靠亲山组所产的腕足类、三叶虫和珊瑚化石其实都是特里奇期早至中期的分子。现在以无可争辩的事实证明了久归于下石炭统岩关阶南好组 ,以及其下的、以往被确定为上志留统足赛岭组、中志留统靠亲山组等所谓两个构造层的地层都应改归于下志留统 (L landovery Series)。北区下志留统仅有鲁丹期中期至爱隆期早期的黑色碳质页岩相和泥页岩相沉积 ,未发现任何大化石。南区下志留统发育较全 ,为细至中粗粒碎屑岩相夹碳酸盐岩相沉积 ,产丰富介壳相各门类化石 ;当时该区所生存的动物群与扬子区早志留世的关系非常密切 ,并在早志留世末期与扬子区大部分地区一样上升为陆 ,表明海南岛地区在当时属于扬子地台区范畴。     

Early Ordovician CA-IDTIMS U–Pb zircon dating and conodont biostratigraphy,Canning Basin,Western Australia

A continuously cored section of more than 300 m through the Nambeet Formation and the basal part of the conformably overlying Willara Formation in the Olympic 1 petroleum well, drilled in the Canning Basin of northern Western Australia, yields valuable information that increases by more than 40% the number of precise isotopic ages available to constrain the Ordovician Period. New CA-IDTIMS U–Pb zircon ages for seven bentonite layers in the Olympic 1 core are integrated into a new conodont biostratigraphic framework for the Early Ordovician comprising four biozones recognised in this well. The weighted mean U–Pb dates range from 479.37 ± 0.16 Ma within the late Tremadocian Paroistodus proteus conodont Biozone, to 470.18 ± 0.13 Ma near the boundary between the Floian and Dapingian stages within the Jumudontus gananda conodont Biozone. The intervening Prioniodus oepiki–Serratognathus bilobatus conodont Biozone (early Floian) and succeeding Oepikodus communis conodont Biozone (middle Floian) are similarly well constrained by isotopic dates centred on ca 477 Ma for the early Floian and by three ages of 473–471 Ma for the middle Floian. The seven new isotopic dates significantly increase the precision of dating for the Early Ordovician, where previously only two ages with limited or imprecise biostratigraphic control were known globally.     

云南永善－大关地区五峰组－龙马溪组黑色页岩生物地层划分与沉积环境探讨:以新地2井为例

由于缺乏对四川盆地西南缘永善-大关地区五峰组-龙马溪组生物地层的详细划分与对比,黑色页岩分布时限及其沉积背景不明确.对新地2井五峰组-龙马溪组黑色页岩岩心开展生物地层研究,识别出了从上奥陶统凯迪阶上部WF1 Dicellograptus complanatus带至志留系兰多维列统埃隆阶顶部LM8 Stimulograptus sedgwickii带的9个生物带和组合.新地2井与宁211井、焦页1井、威202井、巫溪2井黑色页岩生物地层对比结果显示,新地2井的顶界与宁211井、焦页1井黑色页岩笔石带相近,但与威202井、巫溪2井相比低了1个笔石带.结合TOC值标定,新地2井富有机质页岩沉积期为WF2-LM6笔石带,其顶界高于宁211井的LM4笔石带.在笔石生物地层框架内对比了各井黑色页岩的沉积厚度、沉积速率及TOC值,探讨了它们的沉积演化差异及构造背景.靠近古隆起或古陆的沉积区,海侵-海泛稳定期时间呈缩短的趋势,富有机质页岩上界可低至LM5笔石带或以下;远离古隆起或古陆的沉积区,富有机质页岩上界可达LM8-LM9笔石带.受沉积水体深浅差异及古隆起陆源碎屑输入的影响,威远、焦石坝及巫溪地区出现了沉积分异现象.阶段性的海退事件及古隆起的状态变化（隆升与扩大）是广西运动的构造响应.      

Middle Miocene ostracods from Wadi Sudr,westcentral Sinai,Egypt: systematic,biostratigraphy and palaeobiogeographic affinity with the Mediterranean realm

The investigation of the exposed middle Miocene strata from Wadi Sudr yielded well-preserved ostracod carapaces. Detailed taxonomic and paleontological studies led to the recognition of 36 ostracod species belonging to 25 genera, 4 species of them were considered new which fully described. Three assemblage biozones were recorded as follows: Actinocythereis spinosa–Actinocythereis hystrix zone, Chrysocythere cataphracta muricata-Cytheretta africana zone, and Disopontocypris schweijeri-Bythocypris tripolensis zone. The recorded biozones were calibrated with the previously studied middle Miocene planktonic foraminiferal biozones on the same samples and also correlated with the Miocene ostracod biozones from the neighboring countries. Our ostracod assemblages present in the lower and upper parts of the studied section (section II) indicated an inner neritic marine environment of moderate energy of currents and rapid sedimentation, while the assemblages in the middle part showed more deeper (outer neritic) environments with low energy of currents and low rate of sedimentation. The palaeobiogeographic distribution of the studied ostracods showed high affinity with the ostracod assemblages of the southern Mediterranean and moderate to low affinities with that of the northern and eastern Mediterranean respectively. The highly ornamented ostracod species with structures on the carapace were recorded from both Northern and Southern Mediterranean, while the smooth ones were found in the Southern Mediterranean only. The highly ornamented species are more widely distributed in both Southern and Northern Mediterranean than the smooth species. This may indicate that the ornamented species are more able to migrate than the smooth ones.