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1.
六盘山地区下白垩统六盘山群李洼峡组叠层石特征及成因环境探讨 总被引：1，自引：0，他引：1
在六盘山地区下白垩统六盘山李洼峡组中发育了湖相丘状叠层石,通过对叠层石的特征和叠层石地球化学组分分析表明,研究区叠层石主要产于安静低能水体环境,而且对沉积物的捕捉和粘附作用不甚明显,生物膜的钙化和原地微生物引发的沉淀作用是主要成因。经分析,研究区叠层石的Sr/Ba值为12.36,CaO含量为45.56%,总体上,研究区叠层石形成于盐度高且温度较高、气候炎热、蒸发量大而且较为干旱的环境。 相似文献
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《地球科学进展》2020,(1)
作为记录地球早期生命历史的代表物,叠层石已经从35亿年追溯到了古老的37亿年。叠层石为早期生命的存在提供了间接证据,特别是现代碳酸盐叠层石的形成,更加证实了叠层石是蓝细菌生物席的钙化建造物。在现代碳酸盐叠层石中,以下地区的碳酸盐叠层石经前人长期研究已取得一些进展:巴哈马台地的粗粒叠层石、澳大利亚超盐度环境中的细粒叠层石、巴西东南部超盐度潟湖中的细粒叠层石。基于前人的研究成果,通过对现代碳酸盐叠层石的生长机制,以及复杂的微生物活动和沉积过程的追溯,认为本溪火连寨剖面寒武系张夏组中部的叠层石生物丘与现代碳酸盐叠层石存在明显差异,说明现代叠层石的沉积模式还不能完全应用在古代叠层石中。因此,现代碳酸盐叠层石和古代叠层石的对比,可以进一步为了解寒武纪叠层石的构建以及微生物碳酸盐岩工厂提供丰富的思考途径。 相似文献
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自从Kalkowsky在1908年构筑了叠层石的术语之后,叠层石一直是地质学家采用不同方法研究和思考的主题,而且一直被当作证明地球早期生命历史的代表物而得到深入调查。叠层石确实为地球早期生命历史提供了间接而且复杂的证据,所以,现代叠层石确实代表着明显的生物信号而成为研究的焦点。最为引人注目的是,现代叠层石的多样化构成,确实表明了蓝细菌生物席建造了叠层石,而且进一步表明了微生物席转化成叠层石不是一个直接的作用过程。那些反映现代叠层石多样化构成的典型实例包括:(1)南极Untersee地区的湖泊相锥状泥质叠层石;(2)新西兰North群岛被称为煎锅湖的热水湖泊中以及美国黄石国家公园热泉中的硅质叠层石;(3)巴哈马台地、澳大利亚鲨鱼湾以及巴西东南部海湾碳酸盐沉积物构成的叠层石。由于蓝细菌微生物席是否代表了古代叠层石的形态学前体总是存在争议,而且在生命的图像中叠层石一直是一个迷惑的关键片段,因此,现代叠层石的多样化构成,将成为认识古代叠层石形成的关键和窗口。立足于前人的研究成果,追踪和总结现代叠层石的多样化构成,以及它们所代表的沉积作用和微生物新陈代谢活动丰富而复杂的信息,将不但丰富微生物沉积学的研究内容,还将拓宽沉积相分析的基本内容,对深入了解叠层石复杂的沉积学特征和生物学属性具有重要的科学意义。 相似文献
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《现代地质》2015,(6)
在生命历史长河的所有生物化学创造中,光合作用无疑是最伟大的创造之一;因为在光合作用过程中,作为废料的氧气生产作用,确实明显改变了地球海洋、大陆和大气圈的构成。但是,光合作用起源与进化的确切证据,包括光合作用的基本生物学过程,如地球早期光合作用生物的属性、光合作用生物如何获取光合作用装置等,可能已经消失在时间的长河之中;因此,光合作用起源与进化就成为一个引人入胜的重大科学命题。叠层石可能是地球上最为古老的宏观化石,其形态学特征究竟记录了什么样的微生物过程,还存在很多争论。在这个方面的研究中,科学家们获取了两个最为引人注目的创新性认识:(1)锥状叠层石与一些现代微生物席之间的定性化的相似性,表明了古代锥状叠层石的光合作用成因;(2)早在35亿年的水生环境之中,锥状叠层石被认为是在光合作用微生物存在的坚实标志,而且现代锥状聚合体尖端氧气的蓝细菌生产作用较为充分地表明,蓝细菌不但建造了锥状叠层石,而且光合作用产生的氧气气泡可能包含着生氧光合作用进化的时间进程。因此,锥状叠层石的形态学属性及其所蕴含的光合作用信号的研究以及其所取得的创新性认识,不但代表了叠层石研究的一个重要进展,而且成为从沉积学特征去阐释生物学过程的一个典型范例;进行这方面的研究,对深入了解叠层石的沉积学特征和生物学属性具有重要的科学意义。 相似文献
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《古地理学报》2016,(2)
自从Kalkowsky在1908年构筑了叠层石的术语之后,叠层石一直是地质学家采用不同方法研究和思考的主题,而且一直被当作证明地球早期生命历史的代表物而得到深入调查。叠层石确实为地球早期生命历史提供了间接而且复杂的证据,所以,现代叠层石确实代表着明显的生物信号而成为研究的焦点。最为引人注目的是,现代叠层石的多样化构成,确实表明了蓝细菌生物席建造了叠层石,而且进一步表明了微生物席转化成叠层石不是一个直接的作用过程。那些反映现代叠层石多样化构成的典型实例包括:(1)南极Untersee地区的湖泊相锥状泥质叠层石;(2)新西兰North群岛被称为煎锅湖的热水湖泊中以及美国黄石国家公园热泉中的硅质叠层石;(3)巴哈马台地、澳大利亚鲨鱼湾以及巴西东南部海湾碳酸盐沉积物构成的叠层石。由于蓝细菌微生物席是否代表了古代叠层石的形态学前体总是存在争议,而且在生命的图像中叠层石一直是一个迷惑的关键片段,因此,现代叠层石的多样化构成,将成为认识古代叠层石形成的关键和窗口。立足于前人的研究成果,追踪和总结现代叠层石的多样化构成,以及它们所代表的沉积作用和微生物新陈代谢活动丰富而复杂的信息,将不但丰富微生物沉积学的研究内容,还将拓宽沉积相分析的基本内容,对深入了解叠层石复杂的沉积学特征和生物学属性具有重要的科学意义。 相似文献
8.
地球系统变化对叠层石衰减影响的研究综述 总被引：1，自引：0，他引：1
关于叠层石衰减的影响因素至今存在争议。现今研究多集中于显生宙后生动物及微观环境的影响,而忽略了地球系统变化的作用。地史中全球变化从区域尺度调控着大气圈、生物圈、水圈,共同影响叠层石生长所必需的一系列环境因素,与全球叠层石衰减的时间和因果关系具有良好的相关性。在不同地质时期,全球变化以不同的事件组合选择性地作用于造叠层石微生物群落发育以及碳酸盐岩沉积速率上,从而主导着叠层石的兴衰。在综述国内外研究进展的基础上,综合分析了不同时期叠层石衰减与全球变化的响应关系,为今后的相关研究提出了重要线索,同时对未来研究应关注的问题及方向提出了建议。 相似文献
9.
地史中叠层石衰减机制综述 总被引：4，自引：0，他引：4
叠层石是蓝细菌等微生物群体形成的一种层状生物沉积构造,从太古宙到全新世的沉积岩中都有分布.叠层石研究因其重要的理论意义和经济应用价值而备受地质学家关注.虽然叠层石不是实体化石,无所谓演化或进化问题,但它却像微生物和其他生物进化一样,随时间和地球环境的变革而发生丰度和分异度上的变化.现在已知地质历史中共发生了5次重要的叠层石衰减事件,分别为2000Ma,1450Ma,1000Ma,675Ma,460Ma.对这种地质事件的解释主要有后生动物竞争和沉积环境变革两种解释.综合来看,叠层石衰减是全球大环境和整个生物圈大变革的必然结果. 相似文献
10.
冀东高板河中元古代多金属硫化物矿床呈层状和透镜状与容矿岩石整合产出,其中发育大量各种类型的硫铁矿叠层石,呈中、小型丘堆状分布在多金属硫化物矿床中。通过对其进行形态学及显微结构研究和激光拉曼光谱测试表明,高板河硫铁矿叠层石的形成环境明显不同于普通藻叠层石的生长环境,形成于局部强封闭还原的半深海环境中,远离透光带,是海底黑烟囱周围嗜热微生物周期性生长形成的原生微生物沉积构造。硫铁矿叠层石的形态与其所处的环境以及微生物的种类有关。嗜热微生物对于黄铁矿矿床的形成具有重要的促进作用。 相似文献
11.
STEVE KERSHAW SYLVIE CRASQUIN MARIE‐BÉATRICE FOREL CARINE RANDON PIERRE‐YVES COLLIN ERDAL KOSUN SYLVAIN RICHOZ AYMON BAUD 《Sedimentology》2011,58(3):739-755
The Permian–Triassic Boundary sequence at Çürük Dag, near Antalya, Turkey, begins with a major erosion surface interpreted as being the Late Permian lowstand, on which lies ca 0·4 m of grainstone/packstone composed of ooids, peloids and bioclasts. Most ooids are superficial coats on fragments of calcite crystals presumed to be eroded from crystal fans which are no longer present. The erosion surface is smooth and shows no evidence of dissolution; the grainstone/packstone contains intraclasts of the underlying wackestone, proving erosion. Next are 15 m of microbialite comprised of interbedded stromatolites, thrombolites, plus beds of planar limestones with small‐scale erosion. The latter comprise a complex interlayering of stromatolitic, thrombolitic and peloidal fabrics and precipitated crystal fans, which form a hybrid of microbialite and inorganic carbonate, together with bioclastic debris and micrite. The Çürük Dag microbialite sequence is repetitious; the lower part is more complex, with abundant stromatolites and hybrid microbialites. Some of the stromatolites are themselves hybrids composed of peloids and crystal fans. In the upper part of the sequence stromatolites are missing and the rock is composed mostly of recrystallized thrombolites that develop upwards from tabular to domal form. The domes form directly below small breaks in microbialite growth where very thin shelly micrites and grainstones/packstones are deposited. Repetition of facies may be controlled by sea‐level change; a deepening‐up model is consistent with the evidence. Stromatolites (with abundant crystal fans) dominate in shallower water, deepening through hybrid microbialite and interlayered sediments to thrombolite, probably no more than a few tens of metres deep, followed by breaks and renewal of microbialite growth. An interpretation of open marine fully oxygenated waters for microbialite growth is consistent with ongoing parallel work that has identified Bairdioid ostracods in the microbialite, a group known to be open marine. However, other researchers have proposed low oxygen conditions for Permian–Triassic boundary facies globally, so work continues to confirm whether the Çürük Dag microbialite grew in dysoxic or normally oxygenated conditions. The principal stimulus for post‐extinction microbialites is likely to be carbonate supersaturation of the oceans. The microbialite sequence is overlain by a further 25 m of grainstone/packstone (without microbialite), followed by Early Triassic shales. Overall, microbialites form a thin aggradational sequence during an overall relative sea‐level rise, consistent with global eustatic rise following the Late Permian lowstand. 相似文献
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微生物碳酸盐岩油气储层研究现状与展望 总被引：10，自引：5，他引：5
微生物碳酸盐岩是一种重要的油气储集岩。在中国古老深埋碳酸盐岩地层中它们是主要的岩石类型。微生物碳酸盐岩通常可划分为叠层石、凝块石、树枝石、均一石和核形石等五种类型。储层孔隙系统与微生物岩的沉积结构和构造密切相关,窗格孔（洞）和格架孔（洞）是主要储集空间类型。全球中新元古界至中生界都发现了以微生物碳酸盐岩为储层的油气田,资源潜力巨大。 微生物岩储层的岩石类型、沉积构造、相序结构、沉积模式和储层有利相带尚有许多不明晰之处,是今后进一步深化研究的重点方向。 相似文献
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针对现有微生物碳酸盐岩分类不够系统、岩石类型及组合的环境意义不明确、岩相古地理重建缺乏微生物碳酸盐岩沉积模式指导等科学问题,通过塔里木盆地、四川盆地和鄂尔多斯盆地2个元古宇剖面和3个显生宇剖面详细的岩类学和岩石组合序列研究,取得3项成果与认识:①建立了构造尺度和形态特征相结合的系统的微生物碳酸盐岩分类方案。②明确了微生物碳酸盐岩岩石类型及组合的环境意义。风暴浪基面之下远端以欠补偿黑色泥岩和硅质岩沉积为主,近端的下斜坡以具丘状结构的纹理石碳酸盐岩和灰泥丘建造为主;风暴浪基面和正常浪基面之间的上斜坡以小-中型泡沫状、团块状凝块石碳酸盐岩和小-中型柱状、锥状、穹窿状叠层石碳酸盐岩建造为主;正常浪基面与平均低潮线之间以大-中型波状叠层石碳酸盐岩建造为主;平均低潮线之上的潮坪环境以大-中型层(席)状微生物碳酸盐岩、丘状微生物碳酸盐岩建造为主。③建立了缓坡沉积体系和镶边沉积体系微生物碳酸盐岩沉积模式。这些认识对微生物碳酸盐岩岩相古地理重建和储层分布预测具重要的指导意义。 相似文献
14.
Mississippian (Early Carboniferous) stromatolite mounds in a fore-reef slope setting, Laibin, Guangxi, South China 总被引：1，自引：0，他引：1
The Mississippian (Early Carboniferous) is generally a period of scarce carbonate buildups in South China. This study documents
outcrops of stromatolite mounds at Mengcun and Helv villages, in Laibin City, Guangxi Province, South China. The stromatolite
mounds contain various stromatolite morphologies including laminar, wavy-laminar, domal or hemispheroidal, bulbous, and flabellate-growth
columns. Intramound rocks are brachiopod floatstone and dark thin-bedded laminated micrite limestone. Individual stromatolites
at Mengcun village are generally 3–6 cm thick and morphologically represent relatively shallow-water laminar (planar and wavy-undulated
stromatolites) and deeper-water domal, bulbous and columnar forms. Where mounds were formed, the stromatolites continued growing
upward up to 60 cm thick. Thrombolitic fabrics also occur but are not common. Stromatolite microscopic structure shows the
bulk of the lamination to consist of wavy microbialite and discrete thin micritic laminae. These mounds are intercalated in
deep-water fore-reef talus breccia, packstone formed as a bioclastic debris flow and thin-bedded limestone containing common
chert layers of the Tatang Formation (late Viséan). Further evidence supporting the deep-water setting of the stromatolite
mounds are: (1) a laterally thinning horizon of brachiopod floatstone containing deep-water, small, thin-shelled brachiopods,
peloidal micritic sediments and low-diversity, mixed fauna (e.g., thin-shelled brachiopods, tube-like worms and algae) that
have been interpreted as storm deposits, (2) common fore-reef talus breccias, (3) lack of sedimentary structures indicating
current action, (4) preservation of lamination with sponge spicules, and (5) lack of bioturbation suggesting that the stromatolites
grew in a relatively low energy, deep-water setting. The stromatolite mounds are the first described stromatolite mounds in
Mississippian strata of South China and contain evidence that supports interpretations of (1) growth history of Mississippian
microbial buildups and (2) environmental controls on stromatolite growth and lithification. 相似文献
15.
Microbial deposits in the aftermath of the end‐Permian mass extinction: A diverging case from the Mineral Mountains (Utah,USA) 
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下载免费PDF全文 Emmanuelle Vennin Nicolas Olivier Arnaud Brayard Ivan Bour Christophe Thomazo Gilles Escarguel Emmanuel Fara Kevin G. Bylund James F. Jenks Daniel A. Stephen Richard Hofmann 《Sedimentology》2015,62(3):753-792
The Lower Triassic Mineral Mountains area (Utah, USA) preserves diversified Smithian and Spathian reefs and bioaccumulations that contain fenestral‐microbialites and various benthic and pelagic organisms. Ecological and environmental changes during the Early Triassic are commonly assumed to be associated with numerous perturbations (productivity changes, acidifica‐tion, redox changes, hypercapnia, eustatism and temperature changes) post‐dating the Permian–Triassic mass extinction. New data acquired in the Mineral Mountains sediments provide evidence to decipher the relationships between depositional environments and the growth and distribution of microbial structures. These data also help to understand better the controlling factors acting upon sedimentation and community turnovers through the Smithian–early Spathian. The studied section records a large‐scale depositional sequence during the Dienerian(?)–Spathian interval. During the transgression, depositional environments evolved from a coastal bay with continental deposits to intertidal fenestral–microbial limestones, shallow subtidal marine sponge–microbial reefs to deep subtidal mud‐dominated limestones. Storm‐induced deposits, microbialite–sponge reefs and shallow subtidal deposits indicate the regression. Three microbialite associations occur in ascending order: (i) a red beds microbialite association deposited in low‐energy hypersaline supratidal conditions where microbialites consist of microbial mats and poorly preserved microbially induced sedimentary structure; (ii) a Smithian microbialite association formed in moderate to high‐energy, tidal conditions where microbialites include stromatolites and associated carbonate grains (oncoids, ooids and peloids); and (iii) a Spathian microbialite association developed in low‐energy offshore conditions that is preserved as multiple decimetre thick isolated domes and coalescent domes. Data indicate that the morphologies of the three microbialite associations are controlled primarily by accommodation, hydrodynamics, bathymetry and grain supply. This study suggests that microbial constructions are controlled by changes between trapping and binding versus precipitation processes in variable hydrodynamic conditions. Due to the presence of numerous metazoans associated with microbialites throughout the Smithian increase in accommodation and Spathian decrease in accommodation, the commonly assumed anachronistic character of the Early Triassic microbialites and the traditional view of prolonged deleterious conditions during the Early Triassic time interval is questioned. 相似文献
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寒武纪初期不仅发生了宏体生物大爆发,而且也出现了地质历史时期少见的蓝细菌鞘体大规模钙化事件。埃迪卡拉纪—寒武纪之交海水化学性质的转变对真核生物的演化起到了重要作用,但是这种转变对微生物岩发育特征以及蓝细菌钙化事件的产生有无影响,目前尚不明确。鉴于此,对华南上扬子北缘汉南—米仓山地区上埃迪卡拉统—寒武系第二统多个典型微生物岩发育剖面进行了系统野外调查和室内岩石学分析,结果表明:上埃迪卡拉统灯影组叠层石广泛发育,以平铺状、缓波状特征为主,而凝块石既可以呈补丁状分布于叠层石纹层间,又可以呈细小的凝絮状、粘结状特征构成厚层岩层;寒武系第二统仙女洞组叠层石丰度显著降低,以高大、坚硬的丘状隆起为特点,包括单独的凝块石丘,以及微生物与古杯的联合建丘。虽然寒武系第二统微生物岩的层状结构和凝块结构与埃迪卡拉系相比并无太大差异,但是寒武系微生物岩内部保存有大量的钙化微生物化石,已识别出附枝菌(Epiphyton)、肾形菌(Renalcis)和葛万菌(Girvanella)等多种类型。在收集、整理前人有关微生物岩特征和发育资料的基础上,本次研究初步整理出华南寒武系第二统微生物岩的时空分布特点,发现寒武纪第二世第三期是钙化微生物大量发育的一个时期,在随后的第四期达到一个小的高峰。对于此次蓝细菌钙化作用幕的启动机制,除前人提出的海水高钙离子浓度和蓝细菌体内二氧化碳浓缩机制等认识外,寒武纪早期海水性质的转变(方解石质原生矿物受成岩改造程度较低)、适度的陆源碎屑输入(黏土组分保护作用)也有利于钙化微生物结构的保存,应引起重视。 相似文献
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Stromatolite, as the representative of recorder in the early life history of the Earth, has been traced back from 3.5 billion years to 3.7 billion years ago. Stromatolites do provide indirect evidence for the existence of early life on the Earth, especially the composition of modern carbonate stromatolites, which further proves that stromatolites are calcified structures of cyanobacterial mats. Among the modern carbonate stromatolites, the following examples have been studied for a long time: Coarse stromatolites on the platform of Bahamas, fine stromatolites in the ultra-salinity environment of Australia and ultra-salinity lagoon of southeastern Brazil. Based on the predecessors' research results, by tracing the growth mechanism of modern carbonate stromatolites and the complex microbial activities and deposition processes, the formation of stromatolites in the middle of the Zhangxia Formation of Cambrian in the Huolianzhai section of Benxi is obviously different from that of modern carbonate stromatolites, which indicates that the sedimentary model of modern stromatolites cannot be fully applied in the ancient stromatolites. Therefore, the comparison between modern carbonate stromatolites and ancient stromatolites provides a rich way to further understand the construction of Cambrian stromatolites and microbial carbonate factory. 相似文献
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我国中新元古代地层研究中若干问题的探讨 总被引：17，自引：3，他引：14
以叠层石作为生物地层学研究的主要手段 ,并分析了一些新的同位素年龄和其他古生物学资料 ,对 3个中新元古代地层问题进行了讨论 : 1)从元古宙叠层石总体发育过程及陡山沱组新发现的资料看 ,中国南方震旦系(指南沱 ,陡山沱和灯影组 )在层位上应位于胶辽徐淮区的金县群之上 ; 2 )在震旦纪南沱冰期前 ,大约在辽南纪中晚期 ,一起高温氧化并伴随强蒸发事件波及胶辽徐淮区 ; 3)对燕山 ,胶辽徐淮和扬子区中新元古代沉积的构造背景进行了分析。 相似文献