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1.
将宁镇地区上石炭统船山组Sphaeroschwagerina带与二叠系栖霞组底部碎屑岩段之间的灰黑,深灰色中至厚层石灰岩、炭质石灰岩单独划出,称之为镇江组(新义)。石炭二叠系界线放在船山组Sphaeroschwagerina带之顶,镇江组(新义)之底。  相似文献   

2.
本文对苏皖地区石炭纪牙形刺化石作概要介绍。金陵组以Siphondellaisosticha(Cooper),S.cooperi Hass,Polygnathus inornatus E.R.Branson,P.bischoffi Rhodes,Austin&Druce为主,可建立Siphonodella isosticha-S.cooperi带,与我国西南地区岩关阶最上部的牙形刺带相当,其时代应属岩关晚期。老虎洞组以Gnathodus bilineatus Roundy为主,可建Gnathodus blinetus带,与西南地区Gnathodus bilineatus bilineatus带也可对比,其时代为大塘晚期。黄龙组底部白云岩段以Idiognathoides sinuatus(Harris & Hollingsworth),Declinognathcduslateralis(Higgins & Bouckacrt)为主,这些牙形刺为晚石炭世早期的标准分子,可建ldiognathoides sinuatus带。黄龙组纯灰岩段有ldiognathodus delicatus Gunell,I.claviformis Gunell,I.antique Stauffer & Plummer,面貌与华北地区本溪组相似。船山组有Streptognathodus elongatus Gunell,Sweetognathus whitei(Rhodes).Streptognathodus elongatus为华北太原组上部的牙形刺带化石,在北美见于Pennsylvanian系Missourian-Virgillian阶,并延续到下二叠统狼营组。Sweet-ognathus whitei于Sphaeroschwagerina带,被当作早二叠世开始的代表分子。  相似文献   

3.
在赣西北地区石炭纪沉积学及生物地层学研究中取得如下新进展.1.上石炭统原黄龙组顶部首次:采获船山组标准化石,(?)Eoparafusulina sp.,证实了本区有晚石炭世马平期沉积一船山组的存在。2.黄龙组下部白云岩段,发现牙形刺:Idiognathoides sinuatus-Idiognathodus delicatus 动物群 及(?)类:Verella cf.prolixa,Ozawainella pseudorhomboidalis等,为白云岩段时代归属威宁期提供了化石依据。3.作者认为本区黄龙组底部零至三十余米的一套碎屑岩主要为石炭纪威宁期始时海侵初期的滨海相或浅海滞留沉积,与其上白云岩为连续沉积。  相似文献   

4.
长江中下游地区铜、铁、金多金属矿床的形成和分布格局明显受特定的层位、岩性、岩相和古地理环境控制.矿床主要赋存于上石炭统黄龙组、下二叠栖霞组、下、中三叠统大冶群和东马鞍山组.而以上石炭统和下、中三叠统为最主要.主矿体都于碎屑岩相向联酸盐岩相或碳酸盐岩相向碎屑岩相的过度部位.上石炭统的矿床多数在碳酸盐浅滩相与泻湖相和浅水盆地相交接处.下、中三叠统的矿床主要分布于浅滩相与泻湖和泻湖相与交接部位.区内晚石炭世威宁期和早、中三叠世奥伦尼期(鄂东南地区)及安尼锡期(苏皖区)广泛形成的白云岩及蒸发岩沉积.与金属矿床的形成和定位关系密切.特别是膏盐层对燕中期岩浆热液的演化与成矿可能有重要作用。  相似文献   

5.
一、前言 苏浙皖地区上石炭统黄龙组下部,普遍存在一套白云岩地层。这段地层是长江中下游地区铁、铜等矿床的主要控矿层位之一,引起各有关部门的重视。对于该段地层的归属,有不少的争议。近年来,在某些地区本段地层中陆续采集到筛(竹蜓)类、珊瑚化石,提供了一些古生物依据。但在牙形刺研究方面所做工作较少。最近,我室为解决该白云岩的时代归属,组成专题研究组,在苏浙皖地区做了大量工作,系统地采集了牙形刺样品,交给笔者分析鉴定,试图通过牙形刺的研究,对该段地层的归属提供一些粗浅的意见。  相似文献   

6.
<正> 一、地质背景金窝子金矿床位于北山地槽褶皱带的马莲井复向斜中。区内出露地层有上元古界蓟县系玉石山组,寒武系西大山组,中上志留统公婆泉群,上泥盆统金窝子组,下石炭统红柳园组,下二叠统红柳河组,第三系和第四系。上泥盆统金窝子组是岩体和矿体的围岩。该组下部为褐色、灰色、灰绿色薄层钙质细砂岩、粉砂岩和页岩;上部为砾岩、沉积凝灰角砾岩、沉积凝灰砂岩、砂岩、沉积凝灰岩、红色页岩和薄层灰岩。总厚度约为2500m。矿区中的岩浆岩主要为海西期早期的石英  相似文献   

7.
江苏南部的下、中侏罗统,长期以来笼统称之为象山群。本文根据地层岩性特征和大量动植物化石的研究,结合与邻区地层之对比,将江苏南部下、中侏罗统进一步划分为下侏罗统南象山组及中侏罗统北象山组;前者为含煤地层,大致相当于原象山群下部(或下段为),后者为红色地层,大致相当于原象山群上部(或上段)。  相似文献   

8.
四川西昌盆地下二叠统的地层划分对比争议较大,油气勘探程度低。本文通过详细的露头层序地层学研究,结合层序地球化学方法和原理,对西昌盆地下二叠统进行了层序划分和对比,结果表明:西昌盆地下二叠统地层可划分为1 个二级层序、2 个层序组和6 个三级层序;P1q 层序组构成下二叠统二级层序的LST 和TST,层序4 下部发育的(茅口组底部)凝缩层相当于二级层序的最大海泛面,而P1m 中上部(包括层序4 中上部、层序5、6)则构成HST;西昌地区下二叠统层序发育形成过程,总体表现为海平面上升和盆地不断向古陆超覆;沉积序列、古氧相含量、锶含量、碳氧同位素和TOC 的变化旋回揭示西昌盆地早二叠世经历了六次三级海平面变化旋回(六个三级层序),在华南地区乃至全球范围内均可进行对比;建立的层序充填模式揭示出早Hessian 早期全球海平面上升,盆地不断向古陆超覆,奠定了早二叠世西昌海域盆地的轮廓,Roadian 早期海平面上升达到最高位,并沉积一套整个华南均可对比的眼球状灰岩或页状藻灰岩,Capitanian 晚期全球构造海平面下降,结束了西昌地区克拉通盆地的演化阶段。  相似文献   

9.
广东连县水足塘下石炭统六个层位发育丰富的遗迹化石,遗迹大都保留于灰岩、泥灰岩中,共计有九个遗迹属及类型,它们是Zoophycos管状潜穴,Chondrites,Thalassinoides,Teichichnus?枝状潜穴,不规则状潜穴。Planolites和Ancorlchnus。其中刘家塘组下部发现管状潜穴;中上部发现Zoophycos、Thalassinoides、不规则状潜穴Chondrites、Teichichnus?及枝状潜穴,它们形成一遗迹组合;石蹬子组发现Chondrites及Ancourichnus;梓门桥组发现Zoophycos及Planolites.此组合形成于开阔台地相,成员形成于不同时的底质,分属Zoophycos和Glossifungites两个遗迹相。  相似文献   

10.
扬子地体上石炭统船山组内核形石极为丰富,按照内部结构和构造可分五种纹层类型、二种壳层构造和四种核心结构。核形石并非过去所认为的单一的“葛万藻核形石”,而可以根据形态和壳层中的生物组合划分为十种基本类型,其沉积环境有滩、潮下低能带和泻湖等。 石炭纪晚期,由于全球的气候发生强烈分异,从而在低纬度地区产生大量分泌粘液的缠绕生物(藻类为主),核形石就是由这种缠绕生物捕集沉积质点围绕核心而成,其形成过程有四个阶段—核心形成阶段,壳层形成阶段、沉积搬运阶段和成岩后生阶段。 在成岩后生阶段,核形石岩可以产生大量的核间和核内溶孔,这对于油气、矿液的储集和运移是十分有利的。  相似文献   

11.
Captorhinids, a clade of Paleozoic reptiles, are represented by a rich fossil record that extends from the Late Carboniferous into the Late Permian. Representatives of this clade dispersed from the equatorial regions of Laurasia into the temperate regions of Pangea during the Middle and Late Permian. This rich fossil record shows that there was an evolutionary trend from faunivorous to omnivorous and herbivorous feeding habits within this clade. The discovery of well-preserved captorhinid materials in the Middle Permian of China allows us to determine that the new taxon, Gansurhinus qingtoushanensis, gen. et sp. nov, is a member of Moradisaurinae, a clade of captorhinids with multiple tooth rows arranged in parallel. The presence of this moradisaurine in the Middle Permian of south central Asia leads us to suggest that paleogeographic changes during the Permian, with part of what is today China becoming a large peninsula of Pangea, allowed these early reptiles as well as other terrestrial vertebrates to extend their geographic ranges to this region of the Late Paleozoic supercontinent.  相似文献   

12.
采自福建福鼎南溪“构造天窗”的样品分析后获牙形刺。西部所采样品含StreptognathodusfuchenensisZhao,s.elongatusGunnell,Gondolellasp.其时代为晚石炭世晚期。原来这段地层划为下石炭统,应作修改。北部所采样品含IdiognathodusdelieatusGunnell,Neognathodusbassleri(HarrisetHollingsworth),Gondolellasp.其时代为中石炭世早期.进一步证实中石炭统地层的存在。  相似文献   

13.
A new bolosaurid parareptile, Belebey chengi sp. nov., is described from Dashankou, Gansu Province, China, a Middle Permian locality which is known mostly for its therapsid fauna. The material consists of well-preserved mandibular and anterior skull remains and currently represents the largest and latest surviving member of Bolosauridae. Phylogenetic analysis of bolosaurid interrelationships, the first analysis of any clade of Early Permian parareptiles, indicates that the new taxon groups consistently with the other (Russian) members of the genus Belebey, and forms the sister clade to the genus Bolosaurus from North America. The Early Permian Eudibamus cursoris from Germany falls into the basal most position within Bolosauridae. Our analysis also shows that the split between the main bolosaurid lineages must have occurred near or before the Permo-Carboniferous boundary and that the paleo-equatorial region of Laurasia probably served as the center of origination for these parareptiles. A similar pattern can be found in other clades of Paleozoic amniotes, suggesting that this may be the general trend in early amniote evolution.  相似文献   

14.
湘中涟源煤盆地早石炭世测水组、晚二叠世龙潭组煤系是中国东南诸省境内最重要的煤系,具有较大的生气、储气能力。本文从煤系的构造热滨化、构造、沉积及煤层理深等方面论述了研究区测水组、龙潭组煤系中煤层气形成气藏的条件,并指出煤层气的开发远景区应该在煤盆地近南缘的诸含煤向斜南西扬起端,其中各主要区域性断裂交汇而成的断块是最重要的靶区。  相似文献   

15.
Cacops, one of the most distinctive Paleozoic amphibians, is part of a clade of dissorophoid temnospondyls that diversified in the equatorial region of Pangea during the Late Carboniferous and Early Permian, persisting into the Late Permian in Central Russia and China. Dissorophids were a successful group of fully terrestrial, often spectacularly armoured predators, the only amphibians apparently able to coexist with amniotes when the latter started to dominate terrestrial ecosystems. In this paper, we describe excellent new skulls from the Early Permian of Oklahoma attributed to Cacops, Cacops morrisi sp. nov. and provide for the first time detailed information about this iconic dissorophid. These specimens show anatomical and ontogenetic features that will impact on future studies on the evolution of terrestriality in tetrapods. For example, the large, posteriorly closed tympanic embayment has fine striations on an otherwise smooth surface, documenting the oldest known clear evidence for the presence of a tympanic membrane in the fossil record, a structure that is used for hearing airborne sound in extant tetrapods. The skull of C. morrisi also has several features associated with predatory behaviour, indicating that this dissorophid may have been one of the top terrestrial predators of its time.  相似文献   

16.
本文在比较系统介绍朝鲜于60-70年代发现泥盆纪临律群和晚奥陶世—志留纪地层的基础上,论证前者西延登上山东半岛,后者指向辽东、冀东的可能性。  相似文献   

17.
江苏溧阳小梅岭硅灰石矿产于二叠系栖霞组硅质岩中,其成矿热液主要来自庙西花岩岩体。矿体以层状产出,矿石为不规则透镜体,方解石和硅灰石常常互层,常见有硅质岩核心。伴生矿物主要有透辉石、绿帘石、符山石、鱼眼石和萤石。根据x射线衍射分析研究,矿区内硅灰石均属三斜低温硅灰石,其a=-7.934,B0=7.321,C0=7.068,红外光谱和差热分析表明,该硅灰石矿杂质含量较少。根据野外地质条件和理论反应式、反应曲线,小梅岭硅灰石矿形成于半封闭的体系,其形成温度和压力均属中等。  相似文献   

18.
潞西上芒岗红色粘土型金矿赋存于下二叠统岩溶面之上的第三、第四系红色粘土层中 ,矿体形态受地形控制明显 ,呈似层状。品位较高 ,规模中等 ,适合于露天开采。矿体的红土化作用不彻底 ,去硅富铁铝能力低 ,常见高岭石与伊利石共生。矿石中石英、褐铁矿、粘土矿物为主要载金矿物。成矿物质来自燕山中晚期形成的中侏罗勐嘎组中段与二叠系的沙子坡组的断层接触破碎带内的卡林型金矿。在湿热条件下 ,金发生活化、迁移、富集 ,在潜水面附近成矿。  相似文献   

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