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中国西部晚第三—第四纪有孔虫和钙质超微化石的发现及其地… 总被引：2，自引：0，他引：2
报导了中国西北晚中新世－第四纪陆相咸化湖泊介形类群中发现的有孔虫和钙质超微化石组合，并从生态和古地理的角度论证了它们属于非海侵来源，图示了这些生物化石的地理分布。认为主要受到干燥气候下咸化湖泊环境的控制，中新世以来，喜盐水水生生物九介形类，有孔虫和钙质超微生物等随干旱气候控制的咸化湖不断向东扩展。因此，不能笼弘地把这些生物化石作为海侵证据根据地质学现实主义类比原则，提出中国东剖 第三纪没有在大 相似文献
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对我国西北和东北（内蒙古东部）36个地点的新生代-现代陆相咸化湖泊沉积中的433块标本进行了采样分析，在其中15个地点38块标本中发现钙质超微化石10个属：Coccolithus, Reticulofenestra, Cyclicargolithus,Quadrum, Discoaster, Gephyrocapsa, Calcidiscus, Umbilicasphaera,Cotonocyclus, Watznaueria等，多数为原地沉积，也有一部分属于再沉积来源。由此可见，不能笼统地把所有钙质超微化石的发现都当作海相或海侵的证据。陆相咸化湖泊沉积中钙质超微化石的特点是：丰度低，数量稀少；属种分异度低；常与陆相喜盐水生生物共生。第四系和现代陆相咸化湖泊沉积中发现的钙质超微化石属种往往是海相第四系或现代海洋中常见类型。在青海柴达木盆地七个泉构造七心1井中-上始新统下干柴沟组上段岩心中，发现Reticulofenestra bisecta。这是海相中始新世-渐新世沉积中标志化石。看来，利用钙质超微化石进行海、陆相地层对比探索已取得一定进展，但离“统”一级的地层对比还有很大距离。 相似文献
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冀北滦平陆相侏罗—白晋系生物地层界线及候选层型研究进展 总被引：5，自引：1，他引：4
滦平盆地张家沟侏罗－白晋系界线上下为连续沉积的浅湖一半深湖序列,介形类和叶肢介类化石丰富,是中国陆相J／K界线理想的层型候选剖面。通过晚侏罗世和早白垩世介形类,叶肢介生物组合及沉积学与成因地层学的综合研究,认为陆相侏罗－白垩系生物生物地层界线以介形类大个体滦平介Luanpingella的消失,女星介Cypridea的出现,叶肢介Nestoria,Pseudograpta及Keratestheria等的消失以及Eosestheria的始现,扇三角洲平原或前缘亚相或等同亚,微相带的结束为标志,陆相界线层型研究和定义异于海相盆地,陆相环境生物化石的自然缺尔可以通过地层格架建立及沉积亚微相序列高精度地划分,对比予以弥补,并应纳入陆相界线层型的定义中。 相似文献
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冀北滦平陆相侏罗—白垩系生物地层界线及候选层型研究进展 总被引：1，自引：0，他引：1
滦平盆地张家沟侏罗—白垩系界线上下为连续沉积的滨浅湖—半深湖序列,介形类和叶肢介类化石丰富,是中国陆相J\K界线理想的层型候选剖面。通过晚侏罗世和早白垩世介形类、叶肢介生物组合及沉积学与成因地层学的综合研究,认为陆相侏罗—白垩系生物地层界线以介形类大个体滦平介Luanpingella的消失、女星介Cypridea的出现,叶肢介Nestoria、Pseudograpta及Keratestheria等的消失以及Eosestheria的始现,扇三角洲平原或前缘亚相或等同亚、微相带的结束为标志。陆相界线层型研究和定义异于海相盆地,陆相环境生物化石的自然缺欠可以通过地层格架建立及沉积亚微相序列高精度地划分、对比予以弥补,并应纳入陆相界线层型的定义中。 相似文献
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松辽盆地作为中国最大的陆相含油气盆地,是否发生过海水侵入一直存在争议,化石能为该科学问题提供直接解释。在松科1井嫩江组一、二段发现了少量的钙质超微化石,初步鉴定出Calculites obscurus,Calculites ovalis,Quadrum sp.,Micula sp.等属种。上述钙质超微化石广泛分布于晚白垩世海相地层中,通过与国际标准海相化石的对比,将嫩江组一段中、下部的时代限定为Turonian晚期—Maastrichtian期。松辽盆地嫩江组一、二段下部的钙质超微化石保存总体一般,有一定的多样性,具有海相钙质超微化石的特征。松科1井钙质超微化石的分布、古生态及其与有孔虫化石的对应关系表明,松辽盆地嫩江组一段中-下部、二段下部沉积期湖泊水域广阔,全球海平面较高,间歇性的海水侵入事件导致西北太平洋中的钙质超微浮游生物和有孔虫等海洋生物被带入松辽盆地。 相似文献
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杨瑞东 《沉积与特提斯地质》1998,18(1):43-47
本文以沟鞭藻生态为基础,结合我国东部第三纪盆地的地球化学、古生物、岩相古地理、区域地质和全球海平面变化,论证东部含油气盆地在第三纪时不存在海水侵进。出现有“海相”沟鞭藻、有孔虫和钙质超微化石是由于当时湖泊咸化及富养料造成的。同时认为沟鞭藻是广盐性生物,其最适应于半咸水环境。 相似文献
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湘西-黔东地区早寒武世沉积序列及铅锌成矿制约 总被引：2，自引：1，他引：1
湘西-黔东地区下寒武统发育完整,是一套从黑色岩系到碳酸盐岩的沉积序列,代表早寒武世复杂的古地理变迁。纵向上,下寒武统组成一个二级层序,可以进一步划分为5个三级层序,构成总体向上变浅的沉积相序列,同时反映了缓坡型碳酸盐岩台地的生长发育过程,铅锌矿赋存于第四层序高水位体系域中;空间上从北西至南东发育从局限台地、浅滩和微生物(藻)丘相、陆棚相等沉积。岩相古地理对层控铅锌矿具有明显的控制作用,主要分布于台地边缘藻丘和浅滩相与局限台地潮下过渡部位。研究表明牛蹄塘组黑色碳质页岩是铅锌矿源层,清虚洞组灰岩是主要容矿层,其中浊积岩、藻丘体、砾(粒)屑灰岩构成一个完整的铅锌控矿序列。 相似文献
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寒武系是塔里木盆地当前油气增储上产的重点层系,恢复寒武纪的盆地原型是油气勘探的重要基础。利用最新的钻井、地震及露头资料,以沉积相为研究实体,将盆地充填与周缘构造演化相结合,由点→线→面进行分析,恢复了塔里木盆地寒武纪不同时期的构造-沉积环境,并建立了相应的盆地充填演化模式。塔里木盆地寒武纪经历了一次完整的海侵-海退旋回,包括早寒武世早期快速海侵→中寒武世海退、晚寒武世缓慢海侵→寒武纪末海退两个次级旋回,分别对应沉积演化的2个阶段：塔西克拉通内坳陷早寒武世的碎屑滨岸-陆棚相→局限台地相→中寒武世的蒸发台地相,晚寒武世的局限台地相→寒武纪末期的台地暴露不整合;塔东克拉通边缘坳陷为深水盆地相,经历了硅质泥岩→泥岩与灰岩薄互层→碳酸盐岩的岩相演化。寒武纪塔里木原型盆地特征及演化主要受控于Rodinia超大陆的裂解,其构造-沉积格局经历了由震旦纪末的南北分异格局向中-晚寒武世的东西分异格局的演变。 相似文献
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湘西-黔东地区寒武系都匀阶清虚洞期
岩相古地理与铅锌成矿关系研究 总被引：4，自引：0，他引：4
依据地层记录中的两种相变面和两种穿时性,结合上扬子地区寒武系十余条代表性剖面的沉积特征及其横向展布规律,应用等时面优势相成图方法编制了寒武系都匀阶清虚洞期岩相古地理图.区内古地理格局具有西高东低、北浅南深(水深)的特点,沉积自北西向南东超覆,层位逐渐抬高穿时;岩性、厚度、颜色和沉积相类型上的差异是统一沉积背景下沉积物相变、穿时的结果.清虚洞组由灰岩段和白云岩段组成,以发育缓坡型碳酸盐台地为特征,纵向上构成总体向上变浅的沉积相序列,同时反映了缓坡型碳酸盐台地的生长发育过程;横向上从北西至南东发育从混积潮坪相、浅缓坡相、中缓坡相、深缓坡相和陆棚-盆地等沉积.岩相古地理对层控铅锌矿具有明显的控制作用,主要分布于中缓坡相藻灰岩微晶丘中,浊积岩、微晶丘、砾(粒)屑灰岩构成一完整的铅锌控矿序列. 相似文献
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南华纪初，受罗迪尼亚（Rodinia）超级大陆裂解的影响，塔里木陆块进入强伸展构造演化阶段，陆内发育了北东—南西向裂谷体系，裂谷区与两侧高隆带构成“两隆夹一坳”古构造格局。这一古构造格局持续控制了晚震旦世至中寒武世碳酸盐岩沉积序列的充填、演化及油气成藏组合，应将受前寒武纪裂谷构造—沉积演化控制的系列碳酸盐岩台地作为一个成因整体进行系统研究。结果表明:晚震旦世—中寒武世碳酸盐岩台地先后经历了5个重要演化阶段，即晚震旦世同裂谷充填期、震旦纪末抬升剥蚀阶段、早寒武世初海侵深水缓坡型富泥质碳酸盐岩台地阶段、浅水缓坡型碳酸盐岩台地阶段，以及中寒武世蒸发潟湖占主导镶边型碳酸盐岩台地阶段。控制了两套烃源岩、两套储层及一套区域盖层的发育，即形成于震旦纪裂陷槽内潜在烃源岩和早寒武世深水缓坡阶段玉尔吐斯组烃源岩、震旦纪末期受剥蚀淋滤形成的上震旦统微生物丘滩相白云岩储层和早寒武世受岩相和早期云化联合控制的肖尔布拉克组丘滩相白云岩储层，以及中寒武统蒸发潟湖相蒸发岩盖层，构成了上、下两套有效油气成藏组合。与已获得重大突破的四川盆地同期德阳—安岳克拉通内裂陷沉积演化序列及油气成藏组合类比表明，与之具有良好的相似性，且主力烃源岩品质、直接盖层的封盖性能更优于安岳特大型气藏，认为塔里木盆地这一构造—沉积单元具有重要的勘探前景与地位，上部成藏组合更具现实勘探价值。 相似文献
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塔里木盆地西部寒武-奥陶系储层分布特征 总被引：1，自引：1，他引：1
塔里木盆地西部在寒武-奥陶纪大体经历了两次一定规模的海侵-海退沉积,并相应形成了由4个三级旋回层序和2个二级旋回层序构成的层序地层格架.它不仅控制着不同沉积相的平面展布特征,而且控制着生储盖组合的时空分布规律.下寒武统肖尔布拉克组与吾松格尔组的高水位体系域局限台地相沉积,早期普遍经历了白云岩化作用,及后期大气淡水淋溶的综合改造,形成了平面上展布非常稳定的优质针孔状碳酸盐岩储集层段.奥陶系储层主要形成于高水位体系域开阔台地相、台地边缘相和藻滩相中,由于受海水成岩和埋藏成岩环境影响,胶结作用发育,致使储层整体面貌呈Ⅳ类差储集层. 相似文献
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以塔里木盆地北部塔河油田重复采集的高精度三维资料为基础,综合常规的三维资料和钻井资料进行解释,针对寒武系台地-斜坡沉积体系的地震层序、样式、演化与控制因素,讨论台地的起源、不整合面形成环境和海相烃源岩。在塔河油田寒武系地层中识别出16个地震层序。其中,编号为SQ6、SQ7和SQ11的地震层序发育在低位体系域,其他层序由海进和高位体系域组成,具有快速海进、缓慢海退的不对称旋回特征。塔河油田寒武系碳酸盐岩台地总体表现出纵向加积、向东超覆、台地边缘依次向东迁移的大型进积型台地特征,台地边缘向东迁移的距离超过40km。塔河油田寒武系碳酸盐岩台地起源于塔中隆起的北斜坡,经历了缓坡、平顶陆棚、镶边陆棚等台地样式的演化。沉积底形、相对海平面变化、拉张活动、基底沉降和古气候在不同演化阶段起到不同的控制作用,古气候和风向对中—晚寒武世镶边陆棚的发育具有明显的控制作用。下寒武统肖尔布拉克组顶面和寒武系顶面发育区域不整合面,中寒武统沙依里克组和阿瓦塔格组顶面在陆棚边缘发育不整合面,这些不整合面形成于拉张环境。塔河油田寒武系海相烃源岩发育良好,分布广泛,尤其是玉尔吐斯组全区分布,吾松格尔组、阿瓦塔格组和上寒武统的斜坡-盆地相烃源岩分布在塔河东部地区。 相似文献
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湘西—黔东地区寒武系发育完整,是一套从黑色岩系到碳酸盐岩的沉积序列。下寒武统清虚洞组由灰岩段和白云岩段组成,纵向上构成总体向上海水变浅的沉积相序列,同时反映了缓坡型碳酸盐岩台地的发育过程。该组空间上从北西至南东可识别出潮坪相、局限台地相粉细晶云岩、台地边缘浅滩相粉细晶灰岩和台地边缘(滩)丘相微晶灰岩、浅-深缓坡相、陆棚相泥灰岩、台地前缘盆地等沉积。研究表明,地层岩性、岩相古地理对铅锌矿具有明显的控制作用,微晶丘是主要容矿层,与微生物和海底热水关系密切。铅锌成矿明显与浊流沉积和风暴沉积等事件沉积相关,浊积岩、微晶丘、砾(粒)屑灰岩构成一完整的铅锌控矿序列。 相似文献
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From Basin Black Shales to Platform Carbonate Rocks： A Study on Sequence Stratigraphy for the Lower Cambrian of the Upper-Yangtze Region in South China 
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下载免费PDF全文 MEI Mingxiang MA Yongsheng ZHANG Hai MENG Xiaoqing CHEN Yonghong 《《地质学报》英文版》2007,81(5):739-755
In the Upper-Yangtze region,especially in Guizhou Province and its adjacent areas,the Lower Cambrian is well developed and is marked by a succession from black shales of the basin facies to carbonate rocks of the platform facies.The drowning event of the platform occurring at the turn from Sinian to Cambrian resulted in a set of black shales,i.e.the Niutitang Formation,which makes up the bottom part of the Lower Cambrian.With the shoaling of the sedimentary environment,a set of carbonate rocks,i.e.the Qingxudong Formation,was formed in the top part of the Lower Cambrian.Thus,the Lower Cambrian in the study area makes up one second-order sequence that can be further subdivided into five third-order sequences,and forms a regularly cyclic succession of transgression-regression.There is a regularly vertical stacking pattern for the third-order sequences in the second-order sequence.From bottom to top,the succession of the"CS(condensed section) HST(high-stand system tract)"of the third-order sequences is changed into the succession of the"TST(transgressive system tract) CS HST".Correspondingly,the drowning-type sequence boundary is changed into the exposure-type one.Therefore,both the second-order and the third-order sequences have similar sedimentary-facies architectures.A concomitant with these temporal changes, the Lower Cambrian with a thickness of 1000m that contains five third-order sequences is changed into a condensed succession that cannot identify third-order sequences toward the southeast with the deepening of the sedimentary environment.According to the elementary features of the third-order sequences,i.e.the regularity o sedimentary-facies successions in space and the synchronism of sedimentary-environment changes in time,the detailed division of the third-order sequences at main logged sections in different paleogeographical background becomes the basis to establish the sequence-stratigraphic framework that can demonstrate two types of facies-changing surface and two types of diachronism in the stratigraphic records.This sequence-stratigraphic framework shows a growing process of the carbonate platform from the base of the condensed succession formed by black shales of basin facies.Resulting from the rapid transgression at the turn from Sinian to Cambrian the ecological space became open,which formed the antecedent condition of paleogeographical setting for"the Cambrian Biological Explosion".Ultimately,the genetic relationship between the depositional events and the biological-diversity events is very complex and there remain lots of problems that need further research in the future. 相似文献
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下扬子地区在寒武纪处于相对稳定的克拉通盆地背景,盆地沉积格局基本上为两坳夹一隆的特点,中部以碳酸盐岩台地沉积为特征,南北为深水碎屑沉积与碳酸盐沉积为特征。作者以下扬子发育的野外露头为主要研究对象,通过精细测量与观测南京、巢湖、杭州等12个露头点露头资料,建立了下扬子地区寒武纪的层序地层格架。寒武纪可划分为2个二级层序及14个三级层序,作者首次以二级层序体系域为单元对寒武纪进行了岩相古地理编图,并对寒武纪层序—古地理演化3个关键的控制因素进行了分析。下扬子区寒武纪古地理格局相对稳定,继承性地发育了开阔台地、局限台地、台地边缘斜坡、盆地等沉积相类型。 相似文献
20.
MEI Mingxiang MA Yongsheng DENG Jun CHEN Huijun Key Laboratory of Lithospheric Tectonics Lithoprobing Technology of the Education Ministry China University of Geosciences Beijing Department of Oil-Fields China Petrochemical Corporation Beijing 《《地质学报》英文版》2005,79(3):372-383
In the Late Cambrian, the North China Platform was a typical carbonate ramp platform. The Upper Cambrian of the northern part of the North China Platform is famous for the development of bioherm limestones and storm calcirudites and can be divided from bottom to top into the Gushan, Changshan and Fengshan formations. In this set of strata, the deep-ramp mudstone and marls and the shallow-ramp packstones and grainstones constitute many carbonate meter-scale cycles of subtidal type. More tidal-flat dolomites axe developed in the Upper Cambrian of the southern margin of the North China platform, in which limestone and dolomite beds also constitute many carbonate meter-scale cycles of the peritidal type. These cycles are marked by a variety of litho-facies successions. There are regularly vertical stacking patterns of meter-scale cycles in long-term third-order sequences, which is the key to discerning such sequences. Third-order sequence is marked by a particular sedimentary-facies succession that is the result of the environment-changing process of deepening and shoaling, which is genetically related to third-order sea level changes. Furthermore, four third-order sequences can be grouped in the Upper Cambrian of the North China Platform. The main features of these four third-order sequences in the northern part of the platform can be summarized as follows: firstly, sequence-boundaries are characterized by drowning unconformities; secondly, the sedimentary-facies succession is generally constituted by one from deep-ramp facies to shallow-ramp facies; thirdly, a succession of “CS (?) HST” (i.e., “condensed section and highstand system”) forms these four third-order sequences. The chief features for the third-order sequences in the southern part of the North China Platform comprises: more dolomites are developed in the HSTs of third-order sequences and also developed more carbonate meter-scale cycles of peritidal types; the sedimentary-facies succession of the third-order sequences is marked by “shallow ramp-tidal flat”; the sequence boundaries are characterized by exposure punctuated surfaces. According to the changes for the third-order sequences from the north to the south, a regular sequence-stratigraphic framework can be established. From cycles to sequences, the study of sequence stratigraphy from litho-facies successions to sedimentary-facies successions exposes that as follows: meter-scale cycles that are used as the basic working unit actually are litho-facies successions formed by the mechanism of a punctuated aggradational cycle, and third-order sequences that are constituted by regularly vertical stacking patterns of meter-scale cycles are marked by sedimentary-facies successions. On the basis of the changing curve of water depth at each section, the curve of the relative third-order sea level changes in the late Cambrian of the North China Platform can be integrated qualitatively from changing curve of water depth. The correlation of Late Cambrian long-term sea level changes between North China and North America demonstrates that there are not only similarities but also differences, reflecting control of long-term sea level changes both by global eustacy and by regional factors. 相似文献