山东省青州地区寒武-奥陶系界线研究的新进展

首次报道了山东省青州地区尧王山剖面的寒武 奥陶系界线地层的牙形石生物地层学的最新研究成果,在该剖面的炒米店组灰岩建立了 9个牙形石带,其中下奥陶统为 3个带,上寒武统凤山阶为 6个带;并与国内外研究较详细的寒武 奥陶系界线地层进行了对比。在该剖面首次发现了界线牙形石分子Iapetognathusfluctivagus,这也是在整个华北地区的首次报道,这一发现为山东地区乃至整个华北地区的寒武 奥陶系的界线划分提供了新的标尺。     

云南罗平中三叠世大凹子剖面牙形石生物地层及其沉积环境研究

罗平生物群产出于关岭组二段,该段大凹子精细剖面细致的沉积学描述记录显示,剖面岩性变化趋势为:从生物扰动灰岩到含硅质结核的条带泥晶灰岩(钙屑浊积岩)向白云岩演化.剖面详细的牙形石生物地层研究表明,牙形石带属于Nicoraella kockeli带,同时该带可分两个亚带,即Nicoraella kockeli type 1亚带和Nicoraella kocke-li type 2亚带.牙形石生物地层年代确定在Anisian期的Pelsonian亚期.通过大凹子剖面含牙形石段产出环境分析表明:深灰色具脉状层理含泥质灰岩的开阔台地相沉积环境牙形石产出较少且保存一般,而深黑色纹层状泥晶灰岩段台间盆地相沉积环境中牙形石产出丰富且保持完好.大凹子剖面沉积构造研究表明:罗平生物群产出于台间盆地相钙屑浊流沉积环境.     

中国四川龙门山地区泥盆系牙形石

龙门山地区泥盆系地层发育,厚度大,一般为２０００－４００００ｍ,最厚达５０００ｍ以上,化石丰富,门类众多。主要有腕足类、珊瑚、双壳类、三叶虫、头足类、竹节石和层孔虫等。碳酸盐岩地层中发现了大量的牙形石。作者对桂溪、雁门坝和硫铁矿三条剖面中的牙形石做了系统工作,在雁门坝和硫铁矿剖面中,发现了丰富的Ｐａｌｍａｔｏｌｅｐｉｓ（蹼刺）。经分析研究,将该区泥盆系划分出１３个牙形石带和组合。在此基础上,对泥盆系的地层单元及下、中、上泥盆统之间的界线进行了划分,对该区泥盆纪的古生物地理进行了分析。     

南京龙潭正盘山剖面二叠系孤峰组与栖霞组之交牙形类化石再研究

全球二叠系瓜德鲁普统(中二叠统)底界以牙形类Jinogondolella nankingensis的首现为标志, “金钉子”层型被定义在美国得克萨斯州瓜德鲁普山国家公园的Stratotype Canyon剖面。然而, J. nankingensis的模式标本和标准产地以及国际年代地层表中瓜德鲁普统底界的高精度绝对年龄均来自南京龙潭正盘山剖面孤峰组的底部。因此, 正盘山剖面实际上已经成为全球瓜德鲁普统底界的对比标准, 然而该剖面孤峰组和栖霞组上部的牙形类化石序列至今没有系统研究。本文基于新获得的牙形类化石和前人已经描述的标本, 在该剖面栖霞组顶部至孤峰组中部共识别出5属9种, 并将此段地层划分为了3个牙形类化石带, 由下至上依次为: 栖霞组顶部的Sweetognathus subsymmetricus–Pseudosweetognathus costatus组合带, 孤峰组中下部的Jinogondolella nankingensis带和J. cf. aserrata带。新的牙形类生物地层研究结果表明正盘山剖面瓜德鲁普统罗德阶底界应位于孤峰组底部, 孤峰组下部属于罗德阶, 中部属于沃德阶, 罗德阶与沃德阶的界线位置由于硅质岩中较难处理出牙形类化石而不清楚, 推测沃德阶底界可能比当前识别出的J. cf. aserrata带底界更低。临近层位产出的放射虫、菊石和腕足类可以和牙形类化石带进行对比, 并提供辅助对比依据。     

湖北松滋、建始地区中、上奥陶统牯牛潭组至宝塔组牙形类及其地层意义

本文针对湖北松滋响水洞剖面及建始小茶园剖面牯牛潭组至宝塔组地层进行了详细的牙形类序列分析及对比。研究结果表明,自下而上可识别7个牙形类化石带,分别是Lenodus antivariabilis带、Lenodus variabilis带、Yangtzeplacognathus crassus带、Dzikodus tablepointensis带、Yangtzeplacognathus foliaceus带、Yangtzeplacognathus jianyeensis带及Hamarodus brevirameus带。剖面牙形类序列与华南中晚奥陶世综合序列基本一致,但缺失达瑞威尔晚期牙形类生物带(Eoplacognathus suecicus带至Yangtzeplacognathus protoramosus带)的完整记录,这一缺失在扬子台地多个剖面均有记录,可能指示达瑞威尔晚期存在的区域性海平面变化以及全球海洋古环境变化事件。关键词牙形类生物地层地层缺失牯牛潭组–宝塔组中–上奥陶统湖北地区     

湖南花垣中寒武世晚期至晚寒武世早期牙形石动物群

本文描述了湖南花垣排碧剖面中寒武世晚期至晚寒武世早期牙形石动物群的２个新属８个新种。论述了在中国南部首次建立的湖南花垣中－上寒武统牙形石带与华北和东北南部相应牙形石带的对比依据,概述了中国寒武纪牙石研究的简史和现状。     

华南贵州宾夕法尼亚亚纪牙形类Neognathodus动物群:演化及地层对比意义

以华南斜坡相的罗甸纳庆剖面为代表, 我国石炭纪宾夕法尼亚亚纪早–中期地层建立起了基于多个属种的牙形类分带, 并可与全球其它地区同期地层进行广泛对比。Neognathodus属是这一时期一类常见的浅水相牙形类分子, 在北美、东欧等地的浅水相地层中被广泛用作地层划分对比标志。该属分子在我国北方地区浅水相地层中是重要的带化石分子, 而在华南斜坡相剖面中占比非常低。结合现有的生物地层框架, 本文厘清了华南贵州罗甸附近3条斜坡相剖面中Neognathodus属分子的延限, 尝试利用牙形类P₁分子齿台的对称特征将其演化过程归纳为五个阶段, 并提出阶段4中对称分子(如: N. bothrops, N. colombiensis, N. nataliae等)的再次出现可作为全球莫斯科阶底界的辅助对比标志。     

华南乐平统放射虫生物地层学研究进展

以Albaillella分子的地层分布为基础,华南地区晚二叠世地层中已经建立5个放射虫化石带,自下而上分别为:Albaillella cavitata带、Albaillella levis带、Albaillella excelsa带、Albaillella triangularis带和Albail-lella yaoi带.Albaillella cavitata带地层范围相当于牙形石Clarkina postbitteri postbitteri带至Clarkina guang-yuanensis带的底部,其下伏放射虫化石Follicucullus bipartitus-Follicucullus charveti带的地质时代为中二叠世.Albaillella triangulaHs带层位相当于牙形石Clarkina postwangi带,Albaillella yaoi带与牙形石Clarkina yini带相当.华南晚二叠世放射虫动物群演化明显分为两个阶段:第一个繁盛期始于中二叠统上部,延续到A.cavita-ta带下部,以Follicucullus的丰富和多样化为特征;第二个繁盛期出现在A.levis带至A.yaoi带之间,以Albail-lella和Neoalbaillella的鼎盛为特征.     

贵州罗甸边阳镇关刀剖面三叠纪牙形石序列及阶的划分

关刀剖面可初步划分15个牙形石带和动物群,自下而上为:Hindeodus parvus- H. anterodentatus组合带,Neospathodus dieneri延限带,Ns. pakistanensis间隔带( ?) ,Ns. waageni- Parachirognathus动物群,Ns.crassatus延限带,Ns.symmetricus- Ns .homeri间隔带,Chiosellati morensis延限带,Nicoraella germanicus- Nic .kockeli间隔带,Paragondolella bulgarica延限带,Neogondolella constricta间隔带,Ng. constricta cornuda间隔带,Budurovignathus truempyi延限带,Bv. hungaricus间隔带,Bv. mungoensis间隔带,Metapolygnathus polyg-nathiformis动物群。根据牙形石对比划分了阶。安尼阶(或青岩阶)底界年龄可能为247 Ma。     

广西凌云县罗楼地区早三叠世牙形石

罗楼地区下三叠统,经赵金科（１９５９）研究显示,最低层位为Ｖishnuites marginalis菊石带（Gyronitan阶）,张舜新（１９９０）研究广西凤山金下三叠统形石时,未发现最高的牙形石带,当前研究发现,罗楼地区下三叠统牙形石丰富,可识别出Ｈindeodus parvus,Isarciclla staeschei ,Neospathodus waageni,Neospathodus novaehel-landiae,Neospathodus homeri-Neospathodus triangularis,Chiosella timorensis6个牙形石带（组合带）,从而表明该地区不但存在下三叠统底部层位Ｏtoceratan阶,而且存在下三叠统最高的牙形石带,牙形石组合面貌和岩相显示,该牙形石动物群生活环境与田东县作登地区同属盆地相环境。     

河北唐山下奥陶统牙形刺生物地层的新认识

本文作者在安太庠等(1983)研究过的唐山赵各庄剖面,对下奥陶统冶里组和亮甲山组较系统地采集了牙形刺样品,通过对所获牙形刺标本和安太库等(1983)所描述的牙形刺动物群仔细研究后,对包括分带和对比意见有新的认识。安太庠等(1983)把自寒武系凤山组顶部至下奥陶统亮甲山组这段地层,自下而上建立了Cordylodus proavus,Utahconus beimadaoensis-Monocostodus sevierensis,Cordylodus rotundatus-"Acodus"oneotensis,Scolopodus quadraplicatus-S.opimus,Scalpellodus tersus,Serratognathus bilobatus,S.extensus和Paraserratognathus paltodiformis等8带,其中Cordylodus proavus带为寒武系顶,Utahconus beimadaoensis-Monocostodus sevierensis至Scolopodus quadraplicatus-S.opimus等带为下奥陶统冶里组,其余则为下奥陶统亮甲山组,寒武系-奥陶系界线置于Utahconus beimadaoensis-Monocostodus sevierensis带之底。这一牙形刺序列和寒武系-奥陶系界线划分方案在国内被广泛引用至今(王志浩等,2011)。本文通过补充采集到的牙形刺标本和安太庠等(1983)报道的材料,根据一些重要分子在地层中的分布及公认的牙形刺分带原则,对安太庠等(1983)的牙形刺分带方案重新修订,自下而上修订为Cordylodus proavus,C.lindstromi,Iapetognathus jilinensis,Cordylodus angulatus,Chosonodina herfurthi-Rossodus manitouensis,Glyptoconus quadraplicatus,Scalpellodus tersus-Triangulodus aff.bifidus,Serratognathus bilobatus,S.extensus和Paraserratognathus obesus等10带,寒武系-奥陶系界线则置于Iapetognathus jilinensis带之底。根据这一修订后的牙形刺序列,寒武系顶至下奥陶统冶里组部分的牙形刺带可与国内、外相同层位的牙形刺带进行精细对比,而亮甲山组的牙形刺虽有明显的地方性特点,但除其顶部因更具地方性而不能直接对比外,其中下部仍可与华南区下奥陶统红花园组相对比。     

The Guadalupian–Lopingian boundary (Permian) in a pelagic sequence from Panthalassa recognized by integrated conodont and radiolarian biostratigraphy

Guadalupian–Lopingian sedimentary rocks are widely distributed in accretionary complexes in Japan, but the Guadalupian–Lopingian boundary (G–LB) is not well documented from these pelagic sediments. To identify the G–LB and to better correlate an extinction event that occurred around the Guadalupian–Lopingian boundary, we examined the conodont biostratigraphy from a Permian pelagic chert sequence in the Gujo-hachiman section, Gifu, southwest Japan. Age-diagnostic conodonts, including Clarkina postbitteri postbitteri, were found in this section. The biostratigraphic occurrences of these age-diagnostic conodonts can pinpoint the “G–L transitional zone” in the Gujo-hachiman section by comparison with well-studied sections from south China, including the GSSP section. The transitional zone was recognized by the first occurrence horizons of both Clarkina postbitteri hongshuiensis and C. p. postbitteri. The G–LB has been placed at or above the first occurrence horizon of the radiolarians Albaillella yamakitai or Albaillella cavitata in previous studies from China and Japan. We detected the first occurrence horizon of A. yamakitai below the base of the “G–L transitional zone,” in the Upper Capitanian. The conodont biostratigraphy is consistent with the radiolarian biostratigraphy in this section, which can be correlated to relevant sections in China.     

新疆准噶尔盆地西北缘洪古勒楞组时代的新认识

标准地点的洪古勒楞组长期以来一直被认为是准噶尔盆地西北缘,乃至整个新疆北部以海相为主的层位上最高的晚泥盆世晚期的沉积。然而牙形类和微体脊椎动物的研究证实,该组跨弗拉阶－法门阶（Ｆ－Ｆ）界线,它至少包括了一小部分弗拉晚期和主体部分为法门早期的沉积。两个牙形类带ＬａｔｅｒｈｅｎａｎａＺｏｎｅ和ＭｉｄｄｌｅｃｒｅｐｉｄａＺｏｎｅ被识别出,它们在Ｆ－Ｆ界线附近,并分别在大绝灭事件（在ｌｉｎｇｕｉｆｏｒｍｉｓＺｏｎｅ内）之前后。另一个层位更高的牙形类带ＬａｔｅｃｒｅｐｉｄａＺｏｎｅ也可能存在。同时还证实,长期以来一直被认为“正常层序”的标准地点的洪古勒楞组的层序是倒转的。由此,含植物大化石Ｌｅｐｔｏｐｈｌｏｅｕｍｒｈｏｂｉｃｕｍ等的陆相层在下（此层可能归于该组下伏的朱鲁木特组）,而产牙形类和其它丰富的无脊椎动物的海相层在上。按牙形类年代带的年代地层时间表（Ｆｏｒｄｈａｍ,１９９２）,该组距今约３６８－３６４百万年。至于它和邻近地区和布克河组的关系,由于后者发现了更高层位的牙形类,两者还不能完全对比。     

Integrated radiolarian and conodont biostratigraphy of the Middle Permian Gufeng Formation (South China)

Radiolarians are usually abundant in chert sequences and they have thus been widely used for the biostratigraphy of deep-water sediments. However, there are many difficulties in the correlation of radiolarian biostratigraphic schemes with the standard conodont zones. In this study, 21 radiolarian species were extracted from the Gufeng Formation that crops out in the Luojiaba (LJB) section (western Hubei, China), together with 5 co-occurring conodont species. In this way, it is the first time that the Pseudoalbaillella globosa, Follicucullus monacanthus and F. scholasticus radiolarian zones can be directly correlated with the Jinogondolella nankingensis gracilis, J. aserrata and J. postserrata conodont zones. Accordingly, the 3 radiolarians zones are now firmly correlated with the Roadian to middle Capitanian interval (Middle Permian).     

黔南石炭-二叠系界线牙形刺序列的再研究

本文详细描述了华南贵州罗甸纳水和紫云羊场石炭-二叠系的界线牙形刺序列,并自上而下可划分为：Streptognathodus barskovi,S.constrictus,S.isolatus,S.wabaunsensis.S.tenuialueus和S.firmus带,而Strep-tognathodus isolatus的首现则代表了二叠系的底界,本文讨论了世界各地石炭-二叠系界线牙形刺序列的对比。     

湖北宜昌黄花场剖面中/下奥陶统界线附近的牙形剌

重点描述宜昌黄花场剖面中 /下奥陶统界线附近的重要牙形剌共 3属、5种和 2新种Bergstroe mognathussp .nov .,BaltoniodustetrachotomusLiandWangsp .nov .,并对Oepikodusevae带和Baltoniodustriangu laris带分子的首现位置及带的含义进行厘定。作者还在此剖面大湾组下段发现北美中大陆区暖水型牙形剌Tripoduslaevis和Protoprioniodusaranda ,并确定Tripoduslaevis的首现位置在Baltoniodustriangularis带底界之上 0 .3m处。Tripoduslaevis的首次出现曾提议为中奥陶统的底界的标志 (见陈旭等 ,2 0 0 0 ) ,在宜昌黄花场剖面上Tripoduslaevis的首现位置接近Baltoniodustriangularis带底界 ,对确定中 /下奥陶统界线很重要。由于在黄花场剖面可识别出Baltonioduscrassulus—B .gladiatus—B .triangularis演化谱系 ,作者建议以B .triangularis的首次出现作为中奥陶统的底界 ,宜昌黄花场剖面为中 /下奥陶统界线的层型剖面。同时 ,文中将本区的牙形刺带与世界其它地区作了对比。     

Comparative palynostratigraphy of the early Arnsbergian (Namurian) sequences between Great Britain and northwest China

The proposed stratotype section for the Pendleian–Arnsbergian stage boundary, located at Slieve Anierin in Ireland, contains diagnostic ammonoids but the sediments are thermally too mature to permit the recovery of palynomorphs. Detailed investigations undertaken on a prospective parastratotype section at Mirk Fell Gill in northern England however offers the prospect for the precise palynostratigraphic calibration of this boundary. Limited ammonoid and conodont data are available to support these conclusions. Previous work in the British Isles has equated this stage boundary with that between the Bellispores nitidus–Reticulatisporites carnosus (NC) and Stenozonotriletes triangulus–Rotaspora knoxi (TK) miospore zones of Owens et al. [Proc. Yorks. Geol. Soc. 41 (1977) 381–398] and Clayton et al. [Meded. Rijks Geol. Dienst 29 (1977) 1–71]. Data from the Mirk Fell Gill section will be compared with datasets from deposits of similar age in China to assess the degree of change in palaeobiogeographical composition across the Euramerican landmass.     

Carnian-Norian biomagnetostratigraphy at Silická Brezová (Slovakia): correlation to other Tethyan sections and to the Newark Basin

Correlations of Upper Triassic magnetic stratigraphies from Tethyan sections have been hampered by difficulties with conodont biostratigraphy and taxonomy, and discontinuous sedimentation, particularly in the ‘Hallstatt Limestones’ of Turkey and Austria. The magnetic stratigraphy and conodont biostratigraphy from the Upper Carnian to Upper Norian limestones exposed at Silická Brezová (Slovakia) can be correlated to other Tethyan sections and to the continental succession in the Newark Basin. The resulting correlations help to resolve some of the apparent discrepancies in existing conodont zonations, and result in a revised correlation to North American terrestrial vertebrate and palynological zones. The correlations imply that the Norian-Rhaetian boundary lies within Newark polarity zone E17r at ∼207 Ma. The Carnian-Norian boundary lies close to the base of Newark polarity zone E7r at ∼226 Ma. This implies durations for the Norian and Rhaetian stages of 19 Myr and 7 Myr, respectively.     

新疆库鲁克塔格南部突尔沙克塔格群顶部（晚寒武世—早奥陶世）的三叶虫

描述新疆库鲁克塔格地区南部南雅尔当山和却尔却克山突尔沙克塔格群顶部的三叶虫,计10属2亚属9种和3未定种,分为2个三叶虫带,下部Hysterolenus带、上部Dichelepyge sinensis带。根据牙形类化石带的对比,寒武－奥陶系界线应在三叶虫Hysterolenus带之内通过。     

Foraminifera,Radiolaria and Conodont assemblages from the Early Mississipian (late Tournaisian)/Early Pennsylvanian (early Bashkirian) blocks within the Mersin Mélange,southern Turkey: Biochronological and paleogeographical implications

The Mersin Mélange, a sedimentary complex in southern Turkey, includes blocks of various origins within a Late Cretaceous matrix. Two blocks in the Mersin Mélange are herein recognized to be of Carboniferous age. One block (the Kozan Block) is composed of alternating chert and mudstone, and includes radiolarian and conodont assemblages revealing a late Tournaisian (Early Mississippian) age. The other (Keven-West Block) consists of platform carbonate containing abundant foraminifera indicating Bashkirian (Early Pennsylvanian) age. These dates are so far the oldest obtained from the blocks within the Mersin Mélange. A correlation of the lithostratigraphies of blocks in the Mersin Mélange with the coeval Tauride sequences indicates that they correspond to the successions in the Beysehir-Hoyran Nappes. In these nappes, the late Tournaisian is characterized by radiolarian rich chert and mudstone of an open marine environment, whereas the Bashkirian succession represents a shallow water environment with Foraminifera-bearing limestone. The Tournaisian deepening can be ascribed to the opening of a deep marginal basin to the north of the Tauride Platform and uplifting of the northern Tauride-Anatolide Platform margin during the Late Mississippian and Early Pennsylvanian.A shallowing upward sequence started in the Tournaisian with a pelagic sequence followed by platform carbonates of Bashkirian age in the Beysehir-Hoyran Nappes, and could be related to a major glaciation event during late Visean–Serpukhovian resulting in a sea-level drop and deposition of platform carbonates in the Bashkirian. Given the stratigraphic properties of northerly originated nappe packages (Cataloturan, Hadim and Bolkardag) and parautochthonous/autochthonous sequences in Taurides, sedimentation on the Tauride-Anatolide Platform mainly terminated after the Moscovian, except in the Hadim Nappe with sedimentation in a very shallow sea conditions until the end of the Permian. A depositional break corresponding to the Kasimovian–Wordian time interval in these sequences in the Tauride-Anatolide Platform could be related to the effects of both late Paleozoic Gondwanan glaciation and a possible mantle plume occurrence evidenced by the geochemistry of lavas in the Mersin Mélange causing major uplift in the Northern NeoTehys Ocean. However; at the center of the plume, pelagic sequences (e.g., ribbon chert and pelagic limestone) were deposited associated with these lavas due to a progressive developing rift system during the Permian, based on previous studies.