微体古生物-层序地层学相结合方法在地层划分中的应用--以大港滩海埕北断阶带关家堡地区古近系为例

大港滩海埕北断阶带古近系较为复杂,地层划分对比困难,本文采用了古生物组合—高分辨率层序地层学相结合的方法对研究区进行地层划分对比。     

我国北方晚第三纪孢粉序列

我国第三纪地层研究已经历半个多世纪,积累了大量资料.尤其是解放后的三十多年中,取得了许多重大进展.由于我国大陆上新生代地层主要属于陆相沉积,要精确地进行划分和对比,尤其是晚第三纪地层的精确划分和对比确非易事.到目前为止,我国晚第三纪地层研究,无论在生物地层、年代地层、岩石地层或生态地层、磁性地层等方面与世界上研究程度较高的地中海地区相比都有相当差距.最近,李传     

南海北部陆丰凹陷LF14-4-1D井中新世浮游有孔虫生物地层研究

通过对前人在南海北部地区的中新世浮游有孔虫生物地层研究结果的对比,发现其中分带方案有一定的差异,而且分带依据和生物事件年龄也存在争议,特别是利用岩屑样品进行地层划分与对比的钻井尤为突出,对于后续研究和南海地区的地层对比都有较大的不利影响。基于此,我们对比了前人在南海北部中新世浮游有孔虫生物地层的研究成果,结合"2012国际地质年代表"和ODP184航次提供的经天文调谐的浮游有孔虫生物事件年龄,总结了研究区中新世以浮游有孔虫生物事件末现面为基础的13个地层分带,为南海北部地区浮游有孔虫生物地层的划分与对比,特别是生产单位利用岩屑样品进行研究的钻井地层划分,提供了可供对比的基础与依据。并依据上述分带方案,将南海北部陆丰凹陷LF14-4-1D井中新世地层详细划分出早中新世至上新世期间共9个有孔虫化石带或联合带,即早中新世M3带,早-中中新世M4-6联合带,中中新世M7带,M8带,M9带,M10带,M11带,晚中新世M12带和晚中新世-早上新世M13-PL1联合带。     

云南曲靖上志留统牙形刺

云南曲靖地区志留纪地层出露完好,层序清晰,化石丰富,是我国志留纪地层的重要标准剖面之一。该区地层,经多次的研究,早已搞清了地层层序,但在时代划分和对比上,至今仍未统一。我所志留纪地层队沿用了丁文江、王曰伦(1936、1937)对本区的地层的命名,自下而上为关底组、妙高组和玉龙寺组。研究材料是我国志留纪牙形刺的首次报道。自Walliser(1964)对欧洲卡尼克阿尔卑斯地区志留纪牙形刺的系统研究之后,牙形刺在志留纪地层划分和对比上的标准性,就仅次于笔石。     

福建龙岩苏邦栖霞组上部蜓类

本文记叙了福建省龙岩苏邦早二叠世栖霞组上部的类化石,计４属８种,并建立了Ｐｒａｅｓｕｍａｔｒｉｎａｎｅｏｓｃｈｗａｇｅｒｉｎｏｉｄｅｓ－Ｖｅｒｂｅｅｋｉｎａｃｒａｓｓｉｓｐｉｒａ组合带。这些类化石的发现,不但为该地区地层划分与对比提供了新的证据,而且对华南地区早二叠世地层划分有一定意义．     

四川广安谢家槽剖面早―中三叠世有孔虫

四川海相三叠系地层分布广泛,发育富含有孔虫化石的碳酸盐岩,是我国研究三叠纪有孔虫生物地层的理想地区之一。四川广安谢家槽剖面早—中三叠世地层中产丰富的有孔虫化石,共识别出12属34种(包括未定种)。根据有孔虫化石群在地层中的分布特点,自下而上划分出4个组合带,即Rectocornuspira kalhori-Cornuspira mahajeri,Glomospirella vulgaris-Arenovidalina chialingchiangensis,Meandrospira pusilla-Glomospirella irregulariformis和Glomospira sinensis-Arenovidalina amylovoluta组合带。有孔虫化石带的建立为该地区海相三叠系地层的时代确定和划分对比提供了重要的化石依据。     

鄂西奥陶纪介形类

鄂西地区奥陶系发育良好,地层出露齐全,尤以宜昌黄花场、分乡两剖面更有代表性,是我国奥陶系划分和对比的不可缺少的地区之一。本文描述的介形类,采自宜昌,长阳和秭归等地,计有13属19种,其中新种15个。这一发现进一步补充了奥陶纪介形类动物群的内容和充实了对介形类在奥陶纪演化特点的认识,并对地层的划分和对比具有一定的作用。     

塔北井下奥陶系的牙形类序列及其对比

文中记述塔北井下奥陶系的牙形类38属67种,描述其中1新属,4新种,1新亚种。与国内外对比,该区自下而上当前可建立22个牙形类序列(带或组合带)。建议以第5带Pteracontiodus exilis的首现作为塔里木盆地中奥陶统的底界线,从而将鹰山组划分为上、下两组。再结合其它诸如岩石地层、测井地层等综合研究,对塔里木盆地奥陶系现进一步划分为3统7组16个段,以便为研究该地区地层对比和寻找油气资源服务。     

浅析应用CONOP软件构建复合地层剖面的过程和Penalty的选择——以晚泥盆世菊石地层的定量研究为例

随着定量地层学和古生物学研究的发展,约束优化法(CONOP)在定量分析古生物分类单元多样性演化和地层划分对比中发挥了重要作用.本文简要介绍了 CONOP的原理、算法,以及应用CONOP软件进行定量地层对比分析的过程,包括地层古生物数据的选取、厘定与输入,复合剖面的构建,以及最终获得多样性曲线的过程,并以泥盆纪法门期菊石...     

中国北方奥陶纪地层及头足类化石研究的进展

本文描述了头足类化石29种,分属于25属、19科、1亚科、19科,其中24新种、6新属、1新科。对我国北方奥陶纪地层划分进行了详细讨论,将我国奥陶纪地层按生物-沉积特征划分为珠江、扬子、黄河三种类型及珠江、扬子、黄河、新疆、甘青藏和大兴安岭六个生物-沉积区。将黄河区奥陶纪地层划分为下奥陶统冶里组、亮家山组、北庵庄组、马家沟组和中奥陶统阁庄组、八陡组,并和国内外相当的地层进行了对比。     

Chronostratigraphic accuracy of Ordovician ecostratigraphic correlation

Six stratigraphic sections along a 34 km transect down a Middle Ordovician depth gradient (Trenton Group, New York) were ecostratigraphically correlated to 10⁵ year accuracy by pairwise statistical cross-correlation of curves describing each section's depth history in terms of the distribution of fossil marine benthic communities along the gradient. This accuracy is about an order of magnitude greater than that of ordinary biostratigraphic correlation in the sequence, and it is attained even in correlating between very different biofacies. New ecostratigraphic methods illustrated here promise comparable improvements in analyzing many stratigraphic sequences.     

Discovery of the Ordovician Millbrig K-bentonite Bed in the Trenton Group of New York State: implications for regional correlation and sequence stratigraphy in eastern North America

The Ordovician (Chatfieldian) Millbrig K-bentonite Bed is a key stratigraphic marker horizon that is regionally synchronous over much of eastern and central North America. This prominent marker is an independent source of correlation among the major chronostratigraphic and sequence stratigraphic units in this region. The general stratigraphic position of the Millbrig K-bentonite has suggested to some authors that it is identical with the Hounsfield K-bentonite at Dexter, New York (the traditional type area of the Middle Ordovician, or Mohawkian Series in North America), but previously available geochemical and biostratigraphical evidence has been insufficient to confirm this correlation. Analyses of apatites and melt inclusions in quartz phenocrysts from the Millbrig K-bentonite at eight localities in Kentucky, Missouri, Virginia, and Pennsylvania and the Hounsfield K-bentonite at its type locality at Dexter, New York, using high-precision electron microprobe analysis techniques shows that the Millbrig and the Hounsfield have identical apatite and melt inclusion chemistry indicating a geochemical correlation. This correlation is supported by conodont biostratigraphy, and δ¹³C isotope chemostratigraphy. The new data demonstrate that the Millbrig K-bentonite, and therefore the base of the Chatfieldian Stage of the North American Mohawkian Series (by definition), lies very close to the base of the traditional Rocklandian Stage of New York. Furthermore, the Millbrig K-bentonite Bed lies in close proximity to the base of the Taconic supersequence over much of the Midcontinent region and in particular lies just below the M5 sequence boundary recognized in Kentucky and Tennessee. Our results permit extension of the Chatfieldian sequences into New York State and southern Ontario, and contributes to the resolution of the long-standing uncertainty about the position of the base of the Trenton Group in Ontario. Furthermore, viewed in a broad context of regional stratigraphic relations, we conclude that our results suggest that the persistent correlation difficulties reflect diachronous effects of widespread changes in oceanographic circulation patterns that emerged during Taconic Orogeny. Finally, regional differences in the timing and character of sequence bounding surfaces and facies similarities summarized here suggest that the causes of relative sea level change during the Chatfieldian may have been primarily tectonoeustatic mechanisms.     

The early anomodont Venjukovia and the evolution of the anomodont skull

The skull morphology and function of the anomodont mammal-like reptile Venjukovia is described and compared with that of Patranomodon, Eodicynodon, Galeops and Diictodon. Changes in osteology and functional anatomy of these forms are noted.
It is concluded that the acquisition of herbivorous adaptations in the anomodonts may have occurred in the following sequence: division of the external adductor muscles of the jaw into a medial and lateral component, propalinal jaw movement, increased Moment Arm of the external adductors by raising the level of the jaw hinge, anterior migration of the adductor insertions, reduction of the size and number of teeth and acquisition of a horn covering to the jaws, elaboration of the external adductors and reduction of the internal adductors (pterygoideus muscles), and elaboration of palatal areas for mastication of food.
The first (in the morphological sense) committed herbivorous anomodont is identified as the South African form, Galeops. As far as anomodonts are concerned, the major correlate of successful herbivorous feeding is the acquisition of propaliny.
A chronology of character acquisition in the anomodonts cannot yet be drawn up since the stratigraphic correlation of Russian and South African sequences is uncertain. However, it appears that the transition from a generalized carnivore to a committed herbivore took place very rapidly compared to the species longevity of anomodonts.     

Revision of the Cambrian Agnostina (Trilobita?) from Russia

Cambrian genera and species of Agnostina (?Trilobita) found in Russia are revised. Agnostid trilobite species are used as index taxa in chronostratigraphic subdivisions of the traditional Middle and Upper Cambrian in both regional and global stratigraphic scales. The correlation of the regional and international stratigraphic schemes largely depends on the state of knowledge of the regional agnostid fauna. Therefore, an up-to-date revision of this group based on the Russian collections taking into account their global diversity is very timely. For this study we reexamined the type collections of agnostids, including the holotypes of species described by Russian authors. This paper contains new photographic images of the holotypes housed in Russian museums. The compiled data offered solutions for some difficult taxonomic problems of the families Agnostidae, Ptychagnostidae, Peronopsidae, and some genera of Pseudagnostidae, Diplagnostidae. Apart from listing the diversity, this paper serves as the basis for studying the biogeography and evolution of this interesting arthropod group.     

中国南方早更新世主要哺乳动物群层序对比和动物地理

我国南方早更新世哺乳动物群中学术界十分关注是含巨猿的"巨猿动物群"。上世纪50年代广西仅发现个别有确切层位的巨猿地点,现已扩展到鄂、桂、黔、琼和渝5省市12个地点;同时也发现了重要的人猿超科化石及文化遗存。这对探讨人类进化和古文化发展具有重要的意义。依动物群和年代学的研究,本文将早更新世哺乳动物群划分为早、中、晚三期。根据多重地层划分和对比,文中对含哺乳动物主要层位(遗址)的厘定、层序对比提出了一些不同的意见,以供讨论;同时对我国南北动物地理区系间过渡带作了必要的阐明。     

Lithostratigraphic context of Oligocene mammalian faunas from Ulantatal,Nei Mongol,China

The Ulantatal area is well-known for its extraordinarily rich Oligocene mammalian fossils. The Ulantatal fauna was originally considered to be the representative fauna for the Chinese Land mammalian Age, Ulantatalian. However, the abundant fossils collected in the 1980s lack coordinates and/or detailed stratigraphic levels, and have been lumped together as either single, coeval fauna or grouped into three units. This lack of stratigraphic information hampers more precise biostratigraphic division and correlation of the faunas. Here we present a complete lithostratigraphic profile of the Ulantatal Formation with new fossil localities calibrated into the profile. Lithologically, the sequence shows a rather uniform pattern characterized by interbedded reddish to yellowish brown claystones and siltstones, with minor fine-grained sandstones. Preliminary biostratigraphic analysis shows that the Ulantatal Formation covers most of the Oligocene, and offers a long sequence and successive fossil records for understanding the evolution of mammal faunas after the critical Eocene/Oligocene transition.     

Neogene biochronology of Antarctic diatoms: A comparison between two quantitative approaches,CONOP and UAgraph

A quantitative biochronological study by Cody et al. (2008) integrates comprehensive diatom biostratigraphy, magnetostratigraphy, and tephrostratigraphy from 32 Neogene sections around the Southern Ocean and Antarctic continental margin. A recent method, known as Constrained Optimization (CONOP), which can be viewed as a multidimensional version of graphic correlation, is applied to that very interesting database.The goal of the present paper is to discuss some theoretical aspects of quantitative biochronology and to compare the constrained optimization with the deterministic method called Unitary Associations (UAM), a graph theoretical model. We illustrate the fact that the UAM is an extremely powerful and unique theory allowing an in-depth analysis of the internal conflicting inter-taxon stratigraphic relationships, inherent to any complex biostratigraphical database.     

甘肃灵台文王沟(93002地点)晚中新世──早上新世生物地层

文王沟93002地点剖面从下至上被分成4个生物地层带。Ⅰ带可能属于晚中新世保德期中期,Ⅱ＋Ⅲ带属于上新世早期,Ⅳ带属于上新世中期。将各带与93001地点剖面进行了对比。着重探讨了鼠科动物中的Huaxiamys n. sp.向H.primitivus以及Occitanomys n. sp.向Chardinomys的演化规律。