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1.
本文根据环叶菊石科演化序列中，最原始的菊石属在华南，环叶菊石科在二叠纪地层中上延层位最高的菊石属也在华南；世界上环叶菊石科共有１１个菊石属，华南拥有其中１０个敬石属等事实，论证了环叶菊石科发源于华南。文中描述了新发现环叶菊石科的１个新属和３个新种、为该菊石科增添了新材料。 相似文献
2.
描述的菊石产自江西宜春、安福两地,计有1新科、5新属、8新种和一个未定种。根据花桥菊石科(新科)和宜春菊石属(新属),阐述了菊石的演化,并对国际地层对比作了探讨。 相似文献
3.
本文描述了安德生菊石科９种、３属，其中有９新种、２新属。本文对于安德生菊石科中两个亚科的演化关系作了初步探讨。笔者根据在北美和中东发现安德生菊石科的材料，论证了安德生菊石科的分布，是一个具有世界性的菊石科。 相似文献
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5.
本文记述蛇蛉目一个化石新科——吉林蛇蛉科（Jilinorapbidiidae fam. nov.）。新科以其头形、有单眼、各胸节大小、前翅脉序的特征可与其他科区别,在分类上应有它的位置。蛇蛉化石,已发现的很少,这次所发现的标本,十分珍贵,在分类和地层划分方面提供了新的资料。 相似文献
6.
西藏仲巴早二叠世巨日浦组菊石 总被引：1，自引：0，他引：1
西藏仲巴地区,下二叠统巨日浦组上段,以环叶菊石(Cyclolobus)为代表的菊石动物群,是我国继在西藏阿里地区(Diener,C.,1903)发现之后,又一新的发现。经研究包括3属3种,1个未定种(含新种1个)。即:Medlicottia sp., Propinacoceras cf. beyrichi Gemmellaro. Cyclolobus kraffti Diener, C. zhongbaensis Sheng(sp. nov.),时代为早二叠世晚期。环叶菊石(Cyclolobus)是环叶菊石科(Cyclolobidae)中进化最高阶段的代表,是早二叠世晚期的菊石带化石之一,和帝汶菊石(Timorltes)相当,但多见于印度洋沿岸,归于印度太平洋区(东特提斯区)。巨日浦组菊石的发现,对国内外地层对比及板块构造理论探讨具有一定意义。 相似文献
7.
腕足类新科Spinochonetidae(fam.nov.)建立在宜昌地区志留系兰多维列统罗惹坪组下段中部(上埃隆阶)的Spinochonetes Rong,Xu et Yang(1974)和Spinolella(gen.nov.)两个属,以及一个属、种未定的分类单元的基础上。新科成员仅有从腹壳喙部伸出一根直的腹喙刺,这与Chonetoidea超科内的Strophochonetidae科以及Chonestrophiidae科众成员的铰合缘刺都是从腹壳铰合缘上伸出来的有着本质差别。另外,本文还对Spinochonetes以及它的属型种S.notata Rong,Xu et Yang(1974)进行重要图解和补充描述。与此同时,对Spinolella(gen.nov),以及S.minuta(gen.et sp.nov.)进行系统描述和对比。据目前所知,新科成员只分布于我国鄂西、黔东北、陕南和川北等地,属于上扬子台地的土族居民。因为Spinochonetidae(fam.nov.)属于腕足类独特的一个类型,演化快,贝体极小,保存精美,因此具有分类学、地层对比,以及恢复古环境等方面的重要意义。 相似文献
8.
文中描述了我国中三叠世淡水鲎虫的1个新科——新疆鲎虫科(Xinjiangiopsi-dae fam.nov.)及陕西铜川中三叠世(铜川组)鲎虫4个新种。 相似文献
9.
描述了箭蜓科（Gomphidae）一新属种一宽翅辽宁澜箭蜓（Liaoninglanthus latus gen．et sp．nov．）及新属一未定种（Liaoninglanthus．sp．），还对义县光箭蜓（Liogomphus yixianensis Ren et Gao，1996）进行了补充描述。化石全部采自辽西北票黄半吉沟义县组下部（晚侏罗世晚期一早白垩世）。 相似文献
10.
在广西东攀二叠一三叠系界线剖面中发现了Domataceras guangziensis，Lopingoceras guangdeensis Zhao，Liang et Zheng，Schizoloboceras fusuiensis，Agathiceras sp．，Stacheocerassp．，Pernodoceras robustum Chao et Liang，Dushanoceras cf．rotolarium Zhao，Liang et Zheng，Huananoceras cf．peromatum Chao et Liang，Qianjiangocerassp．，Laibinoceras cf．compressum Yang，Glyptophiceras sp．，Lytophiceras cf．chamunda（Diener），Ophicer as tingi Tien，Ophiceras sp．化石。在剖面的第2～12—2层产Pernodoceras，Dushanoceras，Huananoceras和纰njiangoceras化石，均为长兴期菊石带Pseudotirolites.Rotodiscoceras的共生化石。第12—3层产长兴期菊石Laibinoceras cf．compressum Yang。第13-1A-16层产Lytophiceras和Ophiceras，为早三叠世菊石带Ophiceras-Lytophiceras的带化石。东攀剖面菊石的分布及其与华南其他地区的对比研究表明，广西东攀剖面二叠一三叠系界线位于第12—3层（厚55cm）内部或者位于第13—1A层的底部。 相似文献
11.
The family Mesopsychidae Tillyard,1917 presently consists of ten described genera from the Early Permian to the Early Cretaceous of Australia,China,Kyrgyzstan,Russia,South Africa,Tajikistan,and Ukraine.Herein,a new genus and a new species of fossil mesopsychid,Epicharmesopsyche pentavenulosa gen.et sp.nov.,is described from the Middle Jurassic Jiulongshan Formation of Inner Mongolia,China,supplementing the family-level diversity.The well-preserved,new material reveals many characters,including antennae,wing venation,shape and genitalia that increase our morphological understanding of the family,although unfortunately the mouthparts and most of the legs are not preserved.Diagnosis of the Mesopsychidae is emended to include a four-or five-branched MP in both the fore-and hind wings.This is the first documentation of a wing coupling structure in the Mesopsychidae,consisting of three to four frenula bristles on the humeral lobe at the base of the costal margin of both hind wings.Asymmetrical shape and size of the left and right wings on a specimen of E.pentavenulosa gen.et sp.nov.,seems to be a common condition for mesopsychid taxa from northeastern China. 相似文献
12.
Corentin Jouault Vincent Perrichot André Nel 《Proceedings of the Geologists' Association. Geologists' Association》2021,132(3):324-331
A new genus and species of orussoid wasps, Cretorussus vilhelmseni gen. et sp. nov., is described based on new material from the mid-Cretaceous Burmese amber. Its wing venation and body characters lead us to emend the diagnosis of the family Burmorussidae. Cretorussus vilhelmseni gen. et sp. nov. is considered to be a specialized parasitic wasp of wood-living hosts because of the orussid-like ocellar crown, antennae attached well above clypeus, and antennal grooves absent. Interestingly, the third tarsomere carries a prominent lanceolate lobe, serving as part of the host detection. We propose a summary of the orussoid fossil diversity. Lastly, we discuss the implications of several characters of Burmorussidae that are involved in host detection. 相似文献
13.
本文描述了一件保存较为完整的和一件仅头部保存的小型古鳕类化石。这两件化石标本采自宁夏中卫市常乐镇上河沿村和下河沿村石炭纪纳缪尔期晚期土坡组顶部。这类古鳕类身体细长,鳞片不甚发育,部分有印痕保存。舌颌骨微前倾,从顶骨中间部位延伸到颌弓终端,上颌骨后缘向下凸起比向上凸起明显,鳃盖骨比下鳃盖骨略大,眼眶大,且位置靠前,奇鳍条分节分叉现象明显,歪尾型明显,尾鳍上叶缩短,逐步向小型歪尾型演变。总的说来这两件标本拥有更多的软骨硬鳞鱼类向全骨鱼类演化的特征,建议将其定位为古鳕目的一个新属,其科级分类单元的归属在拥有更多的化石资料后再行确定。 相似文献
14.
Aggradational lobe fringes: The influence of subtle intrabasinal seabed topography on sediment gravity flow processes and lobe stacking patterns 
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下载免费PDF全文 Yvonne T. Spychala David M. Hodgson Christopher J. Stevenson Stephen S. Flint 《Sedimentology》2017,64(2):582-608
Seabed topography is ubiquitous across basin‐floor environments, and influences sediment gravity flows and sediment dispersal patterns. The impact of steep (several degrees) confining slopes on sedimentary facies and depositional architecture has been widely documented. However, the influence of gentle (fraction of a degree) confining slopes is less well‐documented, largely due to outcrop limitations. Here, exceptional outcrop and research borehole data from Unit A of the Permian Laingsburg Formation, South Africa, provide the means to examine the influence of subtle lateral confinement on flow behaviour and lobe stacking patterns. The dataset describes the detailed architecture of subunits A.1 to A.6, a succession of stacked lobe complexes, over a palinspastically restored 22 km across‐strike transect. Facies distributions, stacking patterns, thickness and palaeoflow trends indicate the presence of a south‐east facing low angle (fraction of a degree) lateral intrabasinal slope. Interaction between stratified turbidity currents with a thin basal sand‐prone part and a thick mud‐prone part and the confining slope results in facies transition from thick‐bedded sandstones to thin‐bedded heterolithic lobe fringe‐type deposits. Slope angle dictates the distance over which the facies transition occurs (hundreds of metres to kilometres). These deposits are stacked vertically over tens of metres in successive lobe complexes to form an aggradational succession of lobe fringes. Extensive slides and debrites are present at the base of lobe complexes, and are associated with steeper restored slope gradients. The persistent facies transition across multiple lobe complexes, and the mass flow deposits, suggests that the intrabasinal slope was dynamic and was never healed by deposition during Unit A times. This study demonstrates the significant influence that even subtle basin‐floor topography has on flow behaviour and depositional architecture of submarine lobe complexes. In addition, we present a new aggradational lobe fringe facies associations and recognition criteria for subtle confinement in less well‐exposed and subsurface basin fills. 相似文献
15.
本文描述了产于吉林中部的皱纹珊瑚1新属2新种。这些珊瑚化石除具皱纹珊瑚的一般特征之外,还具有六射珊瑚的特点。它对研究六射珊瑚与皱纹珊瑚之间演化关系具有重要意义。 相似文献
16.
Sea floor and shallow seismic data sets of terminal submarine fan lobes can provide excellent planform timeslices of distributive deep‐water systems but commonly only limited information on cross‐sectional architecture. Extensive outcrops in the Tanqua depocentre, south‐west Karoo Basin, provide these three‐dimensional constraints on lithofacies distributions, stacking patterns, depositional geometries and the stratigraphic evolution of submarine lobe deposits at a scale comparable with modern lobe systems. Detailed study (bed‐scale) of a single‐lobe complex (Fan 3) over a 15 km by 8 km area has helped to define a four‐fold hierarchy of depositional elements from bed through to lobe element, lobe and lobe complex. The Fan 3 lobe complex comprises six distinct fine‐grained sandstone packages, interpreted as lobes, which display compensational stacking patterns on a 5 km scale. Between successive lobes are thin‐bedded, very fine‐grained sandstones and siltstones that do not change lithofacies over several kilometres and therefore are identified as a different architectural element. Each lobe is built by many lobe elements, which also display compensational stacking patterns over a kilometre scale. Thickness variations of lobe elements can be extremely abrupt without erosion, particularly in distal areas where isopach maps reveal a finger‐like distal fringe to lobes. Lobe deposits, therefore, are not simple radial sheet‐dominated systems as commonly envisaged. 相似文献
17.
The northern lobe of the Bushveld Complex is currently a highly active area for platinum-group element (PGE) exploration.
This lobe hosts the Platreef, a 10–300-m thick package of PGE-rich pyroxenites and gabbros, that crops out along the base
of the lobe to the north of Mokopane (formerly Potgietersrus) and is amenable to large-scale open pit mining along some portions
of its strike. An early account of the geology of the deposit was produced by Percy Wagner where he suggested that the Platreef
was an equivalent PGE-rich layer to the Merensky Reef that had already been traced throughout the eastern and western lobes
of the Bushveld Complex. Wagner’s opinion remains widely held and is central to current orthodoxy on the stratigraphy of the
northern lobe. This correlates the Platreef and an associated cumulate sequence that includes a chromitite layer—known as
the Grasvally norite-pyroxenite-anorthosite (GNPA) member—directly with the sequence between the UG2 chromitite and the Merensky
Reef as it is developed in the Upper Critical Zone of the eastern and western Bushveld. Implicit in this view of the magmatic
stratigraphy is that similar Critical Zone magma was present in all three lobes prior to the development of the Merensky Reef
and the Platreef. However, when this assumed correlation is examined in detail, it is obvious that there are significant differences
in lithologies, mineral textures and chemistries (Mg# of orthopyroxene and olivine) and the geochemistry of both rare earth
elements (REE) and PGE between the two sequences. This suggests that the prevailing interpretation of the stratigraphy of
the northern lobe is not correct. The “Critical Zone” of the northern lobe cannot be correlated with the Critical Zone in
the rest of the complex and the simplest explanation is that the GNPA-Platreef sequence formed from a separate magma, or mixture
of magmas. Chilled margins of the GNPA member match the estimated initial composition of tholeiitic (Main Zone-type) magma
rather than a Critical Zone magma composition. Where the GNPA member is developed over the ultramafic Lower Zone, hybrid rocks
preserve evidence for mixing between new tholeiitic magma and existing ultramafic liquid. This style of interaction and the
resulting rock sequences are unique to the northern lobe. The GNPA member contains at least seven sulphide-rich horizons with
elevated PGE concentrations. Some of these are hosted by pyroxenites with similar mineralogy, crystallisation sequences and
Pd-rich PGE signatures to the Platreef. Chill zones are preserved in the lowest Main Zone rocks above the GNPA member and
the Platreef and this suggests that both units were terminated by a new influx of Main Zone magma. This opens the possibility
that the Platreef and GNPA member merge laterally into one another and that both formed in a series of mixing/quenching events
involving tholeiitic and ultramafic magmas, prior to the main influx of tholeiitic magma that formed the Main Zone. 相似文献
18.
本文记述的晚石炭世早期菊石群采自宁夏中卫校育川、下河沿的靖远组.所采菊石经鉴定计有14属,24个种,其中包括2个新属,14个新种.本文对这些化石进行了描述,其中就属而言,以Reticu-loceras,Bilinguites,Gastrioceras,Cancelloceras最为丰富,它们分属本区的Reticuloceras带和Gastrioceras带的Cancelloceras bisati-Gastrioceras wongi 亚带.此二带分别与广西七圩的Retites catinatus带和Branneroceras branneri带相当,与西欧的R带和G1亚带亦可比较. 相似文献
19.
Deepwater/deep-marine turbidite lobes are the most distal part of a siliciclastic depositional system and hold the largest sediment accumulation on the seafloor. As many giant hydrocarbon provinces have been discovered within deepwater lobe deposits, they represent one of the most promising exploration targets for hydrocarbon industry. Deepwater exploration is characterized by high cost, high risk but insufficient data because of the deep/ultra–deepwater depth. A thorough understanding of the deepwater turbidite lobe architecture, hierarchy, stacking pattern and internal facies distribution is thus vital. Recently, detailed outcrop characterizations and high–resolution seismic studies have both revealed that the deepwater lobe deposits are characterized into four–fold hierarchical arrangements from "beds", to "lobe elements", to "lobes" and to "lobe complex". Quantitative compilations have shown that hierarchical components of lobe deposits have similar length to width ratios but different width to thickness ratios depending on different turbidite systems. At all hierarchical scales, sand–prone hierarchical lobe units are always separated by mud–prone bounding units except when the bounding units are eroded by their overlying lobe units thus giving rise to vertical amalgamation and connectivity. Amalgamations often occur at more proximal regions suggesting high flow energy. A mixed flow behavior may occur towards more distal regions, resulting in deposition of "hybrid event beds". These synthesized findings could(1) help understand the lobe reservoir distribution and compartmentalization therefore benefit the exploration and development of turbidite lobes within the deep marine basins(e.g. South China Sea) and(2) provide rules and quantitative constraints on reservoir modeling. In addition, the findings associated with deepwater turbidite lobes might be a good starting point to understand the sedimentology, architecture and hierarchy of turbidites in deep lacustrine environment. 相似文献
20.
尼日尔三角洲盆地深水沉积研究是目前世界油气勘探的热点问题之一.通过对三维地震资料、岩心及测井曲线分析,揭示了尼日尔三角洲盆地南部地区新近系深水沉积体系特征.基于不同属性的层序界面识别,研究区划分出SQ1-SQ6共6个三级层序,并建立层序地层格架,进而总结出研究区深水沉积模式.研究区除堆积正常半深海-深海泥岩外,还广泛发育海底扇沉积,海底扇由浊积水道和海底扇朵体组成,其中水道分支少、弯度大,外部形态类似曲流河;朵体平面上成朵叶状分布,可以划分为末端朵体和决口扇朵体.研究区新近系地层自下向上由老到新,相对海平面先下降再上升,SQ1-SQ4层序以海底扇朵体沉积为主,SQ5-SQ6层序以浊积水道沉积为主. 相似文献