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1.
华南五峰组-龙马溪组黑色岩系时空展布的主控因素及其启示 总被引：6，自引：0，他引：6
在回顾五峰组-龙马溪组两个地层单位沿革并重申其定义与划分基础上,重建了华南五峰组-龙马溪组及其相关地层序列的区域地层框架.根据这一框架中奥陶-志留纪黑色笔石岩系的穿时性、以及相关地层序列纵向演化特征与岩石圈板块挠曲模式的联系,结合所发现钾质斑脱岩源岩的板块汇聚背景,以及该阶段海平面升降与黑色岩系对应关系,提出控制该阶段华南黑色岩系的时空展布格局的主要因素有两个,即该阶段自南东向北西的华夏地块与扬子地块幕式汇聚过程所产生的岩石圈板块挠曲-周缘前陆盆地的同向迁移,以及该阶段两次全球性的三级海平面变化快速上升阶段所导致的缺氧及欠补偿水体.本文认为,要在华南奥陶-志留纪(包括其他断代)寻找其他可能的烃源岩层位,可能要首先考虑类似背景下这两种因素综合作用所导致的快速沉降及深水缺氧的沉积环境. 相似文献
2.
华南五峰组—龙马溪组与华北下马岭组的钾质斑脱岩及黑色岩系——两个地史转折期板块构造运动的沉积响应 总被引：14，自引：0，他引：14
华南奥陶—志留纪之交的五峰组—龙马溪组及华北新元古界下马岭组发现的钾质斑脱岩,都产自类似的黑色硅质-碳质页岩/板岩岩系。这两套黑色岩系与上、下地层的接触关系、岩性组成以及垂向序列所揭示的地质过程,具有良好的可对比性,都符合Ettensohn总结的黑色页岩与板块构造运动之间的成因关系模式。岩石元素地球化学研究表明,这两组不同时代的钾质斑脱岩具有相似的源岩岩浆背景,为中酸性的粗安岩-英安岩-流纹岩系列,源于同碰撞岛弧(synCOL-VA)背景的火山喷发活动,与板块边缘的俯冲碰撞密切相关。由于华南五峰组—龙马溪组内斑脱岩及黑色页岩沉积的形成与此间华夏地块与扬子地块的汇聚相关,华北下马岭组的黑色岩系与钾质斑脱岩的形成可能也和华北地块与相邻地块的碰撞相关。推测后者很可能为Rodinia超大陆或Pangea850Ma汇聚时的沉积-地层学响应。 相似文献
3.
奥陶-志留交替时期是地球历史时期中的关键时期,该时期华南地区沉积的五峰-龙马溪组黑色页岩是现阶段我国页岩气勘探重点层位,多套斑脱岩存在于黑色页岩内指示该时期经历过多期连续的火山活动。本文选取了四川盆地东部华地1井和武隆黄莺乡五峰-龙马溪组两条剖面点,以黑色页岩和斑脱岩为研究对象,通过野外考察、元素地球化学等分析方法,系统分析了有机质富集的主控因素(陆源输入、古生产力、古氧化还原条件),并在此基础上分析斑脱岩的发育与否与页岩有机质富集间的关系。两剖面点均表明五峰-龙马溪组黑色页岩TOC呈高-低-高模式,氧化还原指标(V/V+Ni、V/Cr、Ni/Co)指示水体经历了厌氧-富氧-厌氧的过程,生产力指标(Cu、Babio、Sibio)、陆源输入指标(Ti/Al、Zr/Al、Th/Al)表明五峰和龙马溪组具较高的生产力和陆源输入,观音桥组较两者均低,三者与有机碳的相关关系反映氧化还原条件对有机质富集作用最大,生产力次之,陆源输入最弱。从斑脱岩发育特征与有机碳、生产力和氧化还原条件的关系看,频繁的火山活动可能对五峰和龙马溪组有机质的保存产生双促作用,一、为海洋提供营养物质,提升其生物生产力;二、火山灰飘落至海水表面阻止了部分光照进入,海底缺氧环境加剧,造成生物大量死亡并落入海底作为有机质埋藏。 相似文献
4.
中国南方五峰组-龙马溪组页岩中笔石与有机质富集关系探讨 总被引：1，自引：0，他引：1
中国南方奥陶纪-志留纪之交广泛沉积了以五峰组和龙马溪组为代表的笔石页岩。基于对重庆巫溪地区五峰组-龙马溪组底部页岩段中近400件页岩样品中笔石丰度的统计及100件页岩样品有机碳含量（TOC,%）的分析测试结果,选择其中23件不同笔石丰度与TOC的页岩样品开展页岩中笔石体与围岩（非笔石体部分）TOC的对比实验,并结合能谱分析测试结果,探讨笔石与有机质富集的关系。初步研究认为:①五峰组-龙马溪组页岩中笔石体的C、O等元素含量较高,其TOC明显高于围岩,是页岩有机质的贡献者之一;②五峰组-龙马溪组页岩全岩TOC与笔石丰度及笔石体TOC相关性均较差,而与围岩TOC相关性较好,这指示着页岩中笔石丰度对有机质富集影响较小。 相似文献
5.
To decipher the origin of oxygen-deficient shelfal deposits is significant for tracing the distribution of marine source rocks
and interpreting the evolution of depositional environment. The origin of the Middle Permian Chihsia Formation in South China
remains a puzzle for long with its evident oxygen-deficient features but diverse benthos. This paper shows a typical Chihsian
depositional rhythm composed of the massive and the laminated limestones with ecological and geochemical features. Massive
bioclastic limestone from the rhythm was aerobic in paleoxygenation condition indicated by both the ecological and geochemical
features. However, a contradictory oxygenation was inferred for the “laminated” counterpart from the rhythm, with the ecological
signal being aerobic and the geochemical one being anoxic. The difference in ecological and geochemical indications was interpreted
as the instability of paleoxygenation condition in shelf environments, caused by an enhanced paleoproductivity. Rhythmic occurrence
of the oxygen-deficient condition might have been stemmed from paleo-Tethyan paleocurrents flowing across South China.
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Translated from Earth Science—Journal of China University of Geosciences, 2007, 32(6): 789–796 [译自: 地球科学—中国地质大学学报] 相似文献
6.
一条新发现的奥陶系—志留系界线剖面 总被引：1，自引：1，他引：1
在贵州省桐梓县红花园乡南坝子村发现一条新的穿越奥陶系—志留系界线的地层剖面。该剖面自下而上依次出露有宝塔组、涧草沟组、五峰组和龙马溪组等,露头良好,产状平缓,化石丰富。其五峰组观音桥段顶部与龙马溪组交界处,即穿越奥陶系—志留系界线的一段地层,横向上可连续追索逾百米。自五峰组底部到龙马溪组底部(相当于D icellograptus complanatus带—Coronograptus cyphus带下部)的地层中已发现25层斑脱岩。根据生物地层、层序地层等资料初步确认了这些斑脱岩与湖北宜昌等地的斑脱岩具高分辨对比性。该剖面的发现为华南奥陶系—志留系界线附近的各项研究提供了新的资料。 相似文献
7.
页岩孔隙结构及差异性是页岩含气性和产能评价的基础性问题.针对川东南彭水地区五峰组与龙马溪组页岩的孔隙结构已有若干研究成果,然而在页岩孔隙结构差异性和有机孔定量特征方面还缺乏研究.利用低温低压氮气吸附测定和氩离子抛光-场发射扫描电镜（FE-EM）技术,对页岩样品纳米孔隙进行了二维观察与统计以及分形特征计算,研究了3nm至几百nm页岩孔径范围的孔隙结构及其差异性.研究区五峰组-龙马溪组页岩有机孔十分发育;氮气吸附测定页岩孔隙形状包含开放型圆筒状、层状结构狭缝状和墨水瓶状等;扫描电镜观察有机孔形态主要有近圆形、椭圆形和多角形等.五峰组和龙马溪组页岩孔隙结构具有明显的差异性,主要体现在孔径大小、形态和数量上.氮气吸附测定表明,五峰组页岩孔隙比表面积和总孔容较龙马溪组大,微孔所占总孔的比例也较高;五峰组页岩孔径相对龙马溪组更细窄.扫描电镜二维图像观察与统计结果表明,五峰组有机孔径以小于3nm为主,形态以多角形为主;龙马溪组有机孔径以小于0nm为主,形态多呈近圆形和椭圆形.五峰组页岩的分形维值大于龙马溪组页岩,说明前者孔隙复杂程度较高. 相似文献
8.
The Late Permian Dalong Formation in Hubei, Hunan, Guizhou and Guangxi in South China could be subdivided into several sedimentary
types according to the lithology, indicative of the great spatial variations of both the lithology and sedimentary facies.
The Dalong Formation deposited during the highest transgression of Late Permian, in particular under the anaerobic and suboxic
conditions, which shows a strong linkage with the hydrocarbon source rocks. The Dalong Formation has some favorable properties
such as hydrocarbon source rocks, including the sediments deposited in highest transgression sea level, the deep slope sedimentary
environments and the low sedimentary rate, which raises the importance of the investigations on the sedimentary features,
the geochemical properties and their relationship with the oil potential.
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Translated from Earth Science—Journal of China University of Geosciences, 2007, 32(6): 774–780 [译自: 地球科学—中国地质大学学报] 相似文献
9.
The calci-mircobialite is a special carbonate buildup, which is formed due to the activities of different kinds of microbes.
Abundant microfossils preserved in the microbialite show the high-level productivity during deposition, while characteristic
sedimentary minerals and geochemical compositions suggest an anoxic marine environment for organic burial. The high-level
productivity and anoxic sedimentary environment favor the efficient preservation of organic matter and thus the formation
of source rocks. On these points, microbialites could be one of the potential hydrocarbon source rocks, awaiting further geobiological
investigation and exploration. Precambrian and some of the great transitional stages in Phanerozoic are critical periods when
microbialites were well developed. Widespread microbialites have been found in North and South China. Bitumen observed in
many outcrops of Precambrian and late Devonian microbialites further raises the possibility of the calci-microbialite as a
potential hydrocarbon source rock.
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Translated from Earth Science-Journal of China University of Geosciences, 2007, 32(6): 797-802 [译自: 地球科学-中国地质大学学报] 相似文献
10.
Wang Hongmei Ma Xiangru Liu Deng Yang Xiaofen Li Jihong 《Frontiers of Earth Science》2007,1(4):399-404
Understanding the dynamics of organic matter in modern marine water columns greatly favors the geobiological evaluation of
hydrocarbon source rocks. Biolipids could make great contribution to petroleum hydrocarbons due to their comparable chemical
components and the slightly refractory characteristics of biolipids during the microbial/thermal degradation. A variety of
environmental factors such as temperature, CO2 and salinity could affect the biochemical contents in microorganisms. As a result, microorganisms living in a changing environmental
condition might have a different contribution to the petroleum formation. Organic carbon flux is shown to bear a positive
correlation with the primary productivity only within a certain range of biomass volumes in a specific biohabitat. Furthermore,
organic matter is degraded much quickly in a water column with oxic conditions. Therefore, the anoxic condition, along with
the enhanced biological productivity, would be one of the significant factors in the formation of high-quality hydrocarbon
source rocks. The formation of biofilms and microbial mats favors the preservation of sedimentary organic matter by decreasing
the degradation rate of organic matter. Identification of biofilms and microbial mats in sedimentary rocks will thus greatly
help to understand the depositional processes of organic matter finally preserved in hydrocarbon source rocks.
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Translated from Earth Science—Journal of China University of Geosciences, 2007, 32(6): 748–754 [译自: 地球科学—中国地质大学学报 相似文献
11.
贵州正安县奥陶系—志留系界线碳质泥岩Re-Os同位素精确厘定及其古环境反演 总被引：1，自引：0，他引：1
我国上扬子地台地区在奥陶系—志留系之交广泛发育蕴含丰富页岩气资源的五峰组—龙马溪组富有机质沉积岩。采用Re-Os同位素体系对该套沉积地层进行研究,不仅能得到精确的地层沉积年龄,同时根据Re、Os元素的富集机制,对该时期沉积环境进行有效反演,可以为这一阶段发生的地球历史上第二大规模的生物绝灭事件的触发机制提供更合理的解释。本文在贵州正安县班竹1井岩心采集11件碳质泥岩样品,岩心样品连续且完整跨越奥陶系五峰组—志留系龙马溪组界线地层,通过对该样品开展高精度Re-Os同位素研究,获得了奥陶系—志留系地层界线Re-Os同位素年龄为443.68±6.24Ma[2σ,n=7,(~(187)Os/~(188)Os)_i=0.699±0.019,MSWD=0.55],其结果与国际地层委员会发布的年龄(443.7±1.5Ma)高度一致,为奥陶系—志留系界线年龄提供了直接、准确的年龄依据。Os同位素特征反映了大量陆源碎屑参与成岩过程、多期火山活动的发生及冰期向间冰期的转换。连续沉积地层Re-Os同位素特征的变化反映了研究区奥陶系五峰组—志留系龙马溪组沉积环境经历富氧—缺氧—富氧的变化,指示赫南特期冰川事件和火山喷发共同造成了生物大绝灭并促进了有机质的富集,为五峰组—龙马溪组富有机质沉积岩提供了生烃潜力。 相似文献
12.
四川盆地下古生界两套硅质页岩层系(寒武系底部页岩和奥陶系—志留系五峰组—龙马溪组页岩)是其重要的页岩气产层,五峰组—龙马溪组硅质含量与TOC及含气量呈正相关性,暗示硅质矿物对该地区页岩气的生成具有重要意义。但硅质来源复杂,且存在后期硅质流体的注入。因此,本文在总结前人的研究成果基础上,对四川盆地寒武系底部硅质岩系和五峰组—龙马溪组硅质岩系的硅质特征进行了详细的岩石学分析,揭示了3种硅质来源特征:(1)同沉积无机硅质流体;(2)生物硅;(3)后期无机硅质流体。其中寒武系底部以同沉积无机硅质流体和生物硅来源为主,同沉积硅质流体导致有机质快速石化埋藏,有机质内部结构及形态保存较好;五峰组—龙马溪组硅质来源以后期无机硅质流体和生物硅来源为主,有机质在保存过程中受硅质流体的影响很小,有机质腐泥化作用充分,内部结构和形态多数保存较差。该研究初步揭示了两套页岩层系的硅质发育岩石学特征,及其对有机质保存的影响,期望能为四川盆地两套页岩气储层差异性提供新的思路和基础地质数据。 相似文献
13.
晚奥陶世-早志留世时的中上扬子地区,是一个周边被前陆隆起围限的浅海陆棚,沉积环境受武陵-雪峰及黔中前陆隆起带的控制.前隆间的隆后盆地为滞留、还原环境的海域,为黑色页岩沉积提供了空间.上奥陶统凯迪阶五峰组黑色页岩厚度薄而稳定,含笔石生物层和丰富的放射虫,沉积环境为浅海深水盆地;下志留统鲁丹阶龙马溪组下部的黑色页岩为五峰组的继承性沉积,其上部及埃隆阶的龙马溪组为向上变浅的沉积序列,由潮下带潮汐沙坝-潮坪环境黑色含粉砂质页岩、灰色粉砂岩薄互层所构成.沉积序列的变化和时空演化受边缘古隆起的制约.晚奥陶世前陆隆起范围小(平缓),至早志留世鲁丹期,前陆隆起不断扩大并导致盆内构造分隔,发育了大致与前隆平行的坳陷,造成龙马溪组黑色页岩厚度变化大;至埃隆期晚期,海平面相对下降,水体变浅.除个别地区外,中上扬子地区基本结束了黑色页岩沉积. 相似文献
14.
页岩油气是当前全球油气勘探和研究的热点,但其潜力评价一直是难点。该文以中国和北美的四套典型页岩为例,包括北美湖相Green River组、内陆海相Niobrara组、中国环境来评价相龙马溪组和济阳坳陷湖相页岩,发现页岩沉积环境与其油气潜力具有密切关系,因此可通过分析发现这四套页岩的沉积环境都具有页岩沉积环境评价其页岩油气潜力。通过微量元素、生物标志化合物、扫描电镜、X-CT和X射线衍射等方法,发现这四套页岩都具有一定的还原性和较高的生产力,且具有差异性。内陆海相Niobrara组页岩具有弱还原的沉积环境,在四套页岩中有机碳含量较低,呈块状沉积构造,裂缝与微裂缝较少,储集空间相对有限。焦石坝海相龙马溪组页岩为还原的沉积环境,岩石以富含有机质的硅质岩为主,可观察到大量的大孔隙与少量的微裂缝。Green River页岩和济阳坳陷页岩形成于陆相咸化的强还原沉积环境,有机碳含量高,页岩以纹层状结构为主,岩石组成脆性矿物含量高,含有大量的裂缝。可见,具有强还原沉积环境的页岩通常具有较好的勘探前景。 相似文献
15.
On the geobiological evaluation of hydrocarbon source rocks 总被引：1，自引：0，他引：1
Xie Shucheng Yin Hongfu Xie Xinong Qin Jianzhong Hu Chaoyong Yan Jiaxin Huang Junhua Zhou Lian Yang Xianghua Wang Yongbiao Xu Sihuang 《Frontiers of Earth Science》2007,1(4):389-398
Hydrocarbon source rocks are characterized by the hydrocarbon discharge, and the alteration and variation in organic compositions
and organic content due to the enhanced thermal maturation. These variations throw constraints on the application of the conventional
inversion evaluation of hydrocarbon potential by assessing the residual organic matter left in source rocks. Geobiology, probing
the interaction between the life system and the earth system, provides new principles in deciphering the whole dynamic processes
related to the organic evolution history from living biomass to organic burial. Geobiological subdisciplines, including molecular
geobiology, geomicrobiology, geoecology and biogeochemistry, offer new methodology and techniques to estimate the paleoproductivity,
depositional organics and organic burial capacity and their components. Geobiofacies, newly proposed herein, is terminologized
to define the geobiological dynamic processes through the combination of biofacies with organic facies and sedimentary facies,
and expressed by the biohabitat types, paleoproductivity, depositional and preserved organics. Geobiofacies is identified
as a useful means to create the geobiological evaluation system, which in turn rectifies the conventional evaluation system
for the marine source rocks.
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Translated from Earth Science—Journal of China University of Geosciences, 2007, 32(6): 727–740 [译自: 地球科学—中国地质大学学报] 相似文献
16.
Binsong Zheng Renjie Zhou Xiuping Wang Zhaohui Xiao Yao Chen 《International Geology Review》2020,62(10):1262-1272
ABSTRACT The intraplate Kwangsian Orogeny is a key orogenic event in South China in the mid-Paleozoic. We re-examined the evidence for the Yichang Uplift, an inferred geographic feature during the Kwangsian Orogeny, to evaluate its timing and nature. Field, sedimentological, mineralogical and geochronological data were collected from the Late Ordovician-Early Silurian Xiaohe section, Hunan-Hubei area. Results suggest that the Xiaohe section is composed of the Late Ordovician Wufeng Formation black shale in the lower part and the Early Silurian Longmaxi Formation black shale in the upper part. We found that the clay layers interbedded in the Wufeng Formation are altered rhyolitic tuffs instead of parts of a subaerial wreathing crust. LA-ICP-MS U-Pb dating of zircons in the top tuff layer of the Wufeng Formation yielded an age of 447.0 + 1.4/- 2.2 Ma, consistent with biostratigraphic data, providing a radiometric constraint for the sedimentary break existed between the Wufeng and Longmaxi formations and confirming the absence of the Hirnantian (latest Ordovician) Guanyinqiao Formation in the study area. Our data support that the Yichang Uplift was a submarine highland possibly initiated by the reactivation of the inherited Jianshi-Enshi Fault in the Hunan-Hubei area during the Kwangsian Orogeny. 相似文献
17.
我国中上扬子地区下古生界黑色页岩是震旦系、二叠系大中型气田的重要烃源岩,同时其自身也具有形成页岩气藏的巨大潜力。初步研究表明,中上扬子地区下古生界有利页岩气层主要发育在下震旦统陡山沱组、下寒武统筇竹寺组、上奥陶统五峰组和下志留统龙马溪组,这些层位的黑色页岩厚度、有机碳含量、以及Ro值等各项参数均符合形成页岩气藏的特征,是今后页岩气勘探的潜力地层。 相似文献
18.
学者们在页岩层序划分与构成等方面还存在较大分歧;其次,现有研究中针对页岩非均质性在层序格架内的变化特征及成因规律方面亦有不足.五峰组-龙马溪组页岩是上扬子地区重要的页岩气勘探层位之一,通过钻井岩心、露头剖面、常规测井、能谱测井和地球化学参数等资料,对上奥陶统五峰组-下志留统龙马溪组黑色页岩层序地层学进行了定量分析.在五峰组-龙马溪组识别出3个三级层序,其中五峰组为一个三级层序,进一步划分出海侵体系域（五峰组下部黑色页岩）和高位体系域（五峰组上部观音桥段）;龙马溪组一段作为一个三级层序,进一步划分出海侵体系域、早期高位和晚期高位体系域;龙马溪组二段和三段为一个三级层序,进一步划分出低位体系域、海侵体系域和高位体系域.以不同体系域为单元分析了五峰组-龙马溪组层序发育与沉积环境特征,揭示了各体系域内古生产力与水体氧化还原条件对有机质富集的控制机理,总结并提出了系统的五峰组-龙马溪组黑色页岩层序地层垂向演化模式. 相似文献
19.
Geochemical and mineralogical analyses, in addition to isothermal adsorption experiments on field samples, are used to characterise the sedimentary environments, reservoirs and adsorbed gas of the Upper Ordovician Wufeng–lower Silurian Longmaxi formations in the Sichuan Basin and its peripheral areas. The sedimentary environment of the Wufeng and the lower part of Longmaxi formations is a deep-water shelf with five different lithologies identified: siliceous shale, black shale, siltstone, biolithite limestone and bentonite. The black shale in the Wufeng and the lower part of Longmaxi formations is 50 m thick, with an average organic carbon content (TOC) of 3.81 wt% and a maturity (Ro) of 1.62%. Quartz comprises 54.94 vol% of the shale and positively correlates with the TOC. Micropores in the black shale include intergranular pores, intragranular pores, organic matter pores and microfractures. Among these pores, spaces between clay sheets and organic molecules represent a favourable storage space for the accumulation and preservation of oil and gas. The Langmuir volume parameter ranges between 1.52 and 3.01 cm3/g, with an average value of 2.33 cm3/g. The presence of organic matter pores and pores between clay sheets in the black shale is the main and controlling factor for accumulated gas. 相似文献