首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 187 毫秒
1.
层序地层学及旋回地层学的大量研究成果研究,浅海相地层的旋回记录是一种普遍现象。在进行露头层序地层研究中,不能机械地识别层序界面及进行体系划分,岩性、岩相,相序及其有序又珈形式才是研究的基础和关键。旋回层序的界面有两种类型;暴间断面及加深饥饿间断面。  相似文献   

2.
鄂北南化地区寒武纪缓坡沉积及层序   总被引:1,自引:0,他引:1  
王翔  胡健民 《沉积学报》1996,14(3):47-55
出露于鄂北南化地区的寒武纪地层,总厚约1400m,主体为一套碳酸盐岩。对沉积岩相及相组合的分析表明,本区寒武系主要是形成于碳酸盐缓坡之上,并可以划分出四种主要的沉积相带:浅水陆棚、深水缓坡、浅水缓坡建隆和近岸浅水缓坡。本文还初步研究了区内寒武系露头的层序地层学特征,划分出两个亚层序,并探讨了亚层序内部岩相的不同叠置类型及其在时间上的演化与相应的海平面升降变化。通过与已有的旋回性海平面变化模式相对比,得出了本区寒武纪层序内部的次级旋回可能指示第三级海平面变化旋回的认识。  相似文献   

3.
以高分辨率层序地层学原理为指导,通过对研究区钻井资科的分析和对比,对金桥矿区石炭-二叠系含煤地层基准面旋回进行了高分辨率层序划分.将含煤地层段划分为6个长期基准面旋回、9个中期基准面旋回和29个短期基准面旋回,其中短期基准面旋回可分为3类、中期基准面旋回可分为2类.通过对该区含煤地层岩性特征、沉积环境及聚煤作用的研究,...  相似文献   

4.
苏皖地区石炭系露头层序地层研究   总被引:12,自引:2,他引:10  
应用露头层序地层学基本原理和方法,在详细的岩石岩相学、沉积学.地球化学研究和精细的地层划分对比基础上,对苏皖地区石炭系地层进行了露头层序地层研究.阐述了沉积层序的各种界面的露头标志,探讨了三级层序和层序区域对比的基本特征.研究表明,苏皖地区石炭系可识别出9种主要岩相、20种微相和11个三级沉积层序.Ⅰ型沉积层序边界识别标志有地表或海底侵蚀、地层上超,界面上下岩性岩相、古生物及氧碳同位素值的突变,界面的区域可对比性等,在研究区主要表现为古风化壳面、古岩溶面、侵蚀面和暴露面四种类型.陆表海盆海水较浅,沉积物常露出水面而遭受侵蚀,形成较多的Ⅰ型层序边界.三级层序发育TST,LST不发育或难以识别。  相似文献   

5.
沉积地层旋回性记录中几个理论问题的认识   总被引:4,自引:0,他引:4  
层序地层学及旋回地层学的大量研究成果表明,浅海相地层的旋回性记录是一种普遍现象。在进行露头层序地层研究中,不能机械地识别层序界面及进行体系域划分,岩性、岩相、相序及其有序叠加形式才是研究的基础和关键。旋回层序的界面有两种类型:暴露间断面及加深饥饿间断面。不管是间断面还是凝缩段均存在一个级别归属问题。判断一个旋回层序是否存在的标准,是看组成它的“成因相关的相序”是否存在空间上的有序性及时间上的同步性  相似文献   

6.
安微巢县下三叠统层序地层研究   总被引:10,自引:0,他引:10  
童金南 《地球学报》1997,18(2):215-219
安徽巢县马家山三叠系剖面其特殊的古构造和古理位置,在下扬子区域层序地层研究中处于重要位置。本文在沉积学、旋回分析和生态地层学等综合分析的基础上,结合下扬子区区域层序地层的发展特点,总结了该剖面下三叠统层序发育型式、发育特点及其演变过程,并以此为例论述了单剖面露头层序地层研究的基本方法。  相似文献   

7.
渤海湾盆地黄骅坳陷缓坡带新近系是以陆相河流沉积为主的地层,从层序地层学的角度寻找该类沉积中特征的岩性—地层油气藏是当前关注的焦点。以黄骅坳陷新近系明化镇组、馆陶组为研究对象,充分利用已有的岩心、钻井和地震资料,在层序界面识别基础上,建立了研究区高分辨率层序地层格架,划分出1个超长期旋回层序、7个长期旋回层序和若干中短期基准面旋回层序。馆陶组发育多断缓坡型层序地层模式,层序结构为仅保留基准面上升半旋回的非对称型,沉积充填以切割叠置的辫状河砂体为主;明化镇组发育稳定缓坡型层序地层模式,层序结构为上升半旋回大于下降半旋回的不完全对称型,沉积充填为泥包砂的曲流河沉积。层序发育早期的多断坡折带内侧辫状河复合砂体是研究区新近系最有利的储集砂体。  相似文献   

8.
通过对传统米级旋回成因的讨论,提出了在传统的四种米级旋回之间存在米级旋回的过渡类型,即单岩性米级旋回的观点,并从米级旋回的成因及层序—岩相古地理方面对单岩性米级旋回的形成模式进行了分析,在野外露头对北京西山张夏组碳酸盐岩进行了旋回地层划分,就沉积间断面不易识别的旋回地层进行了讨论,并识别出了单岩性米级旋回。层序—岩相古地理背景下的米级旋回模式,可对米级旋回的平面展布进行预测;单岩性米级旋回的发现,有利于提高三级旋回层序识别及划分的精度。  相似文献   

9.
陈蓉  王峰  李勇 《古地理学报》2016,18(6):976-985
渤海湾盆地黄骅坳陷缓坡带新近系是以陆相河流沉积为主的地层,从层序地层学的角度寻找该类沉积中特征的岩性—地层油气藏是当前关注的焦点。以黄骅坳陷新近系明化镇组、馆陶组为研究对象,充分利用已有的岩心、钻井和地震资料,在层序界面识别基础上,建立了研究区高分辨率层序地层格架,划分出1个超长期旋回层序、7个长期旋回层序和若干中短期基准面旋回层序。馆陶组发育多断缓坡型层序地层模式,层序结构为仅保留基准面上升半旋回的非对称型,沉积充填以切割叠置的辫状河砂体为主;明化镇组发育稳定缓坡型层序地层模式,层序结构为上升半旋回大于下降半旋回的不完全对称型,沉积充填为泥包砂的曲流河沉积。层序发育早期的多断坡折带内侧辫状河复合砂体是研究区新近系最有利的储集砂体。  相似文献   

10.
华北地台中寒武世米级旋回层序与复合海平面变化   总被引:2,自引:0,他引:2       下载免费PDF全文
笔者在对华北地区中寒武统鲱滩碳酸盐建造露头层序地层学研究工作中首次识别出层序中最基本的地层单元-米级旋回层序,它是露头层序分析最基本的工作单元。本文总结概括出不同体系域内米级旋回层类型和特征。这些米级旋回层序在垂向上叠加构成高级旋回层序时表现出时期性和规律性。这种不同级次的旋回层序的形成受不同动力成因引起折具不同周期和复合海平面变化的控制。  相似文献   

11.
下扬子区二叠系层序地层格架   总被引:1,自引:1,他引:0  
针对研究区钻及二叠系的井甚少,现有的几条地震剖面质量欠佳的状况,采用露头层序地层学的方法在8条主干剖面、数十条辅助剖面详细研究的基础上将研究区二叠系划分为11个Ⅲ级层序(栖霞阶为3个层序,茅口阶为3个层序,吴家坪阶为3个层序和长兴阶为2个层序)。以具区域性分布的生物化石带为主,辅以岩性组合、岩相特征、垂向相序特点及地质事件,对研究区二叠系进行详细区域层序对比,总结了二叠系层序特点。  相似文献   

12.
Griesbachian Cyclostratigraphy at MajiashanSection, Anhui Province, China   总被引:4,自引:0,他引:4  
INTRODUCTIONAs a large regression continued over the world at the endof the Paleozoic, a new remarkable transgression was intrudinginto the Lower Yangtze located in the eastern Tethys duringthe Late Permian, resulting in many excellent continuous marine Permian-Triassic sequences in this region. But the middleTriassic indosinian movement transformed this region from marine to continental factes, resulting in the deposition of theLower Triassic in the marked regression setting prior to …  相似文献   

13.
The sedimentary cycles of the Cenomanian to Maastrichtian were investigated in the Basco-Cantabrian Basin (BCB) in northern Spain (Provinces of Alava, Vizcaya and Burgos). The depositional area was a distally steepened carbonate ramp which extended from Catalonia northwestwards to the Basque country. The investigated sediments range from calciturbidites and pelagic marls to marl-limestone alternations deposited on a distal carbonate ramp. Shallow marine limestones, marls and intertidal clastics and carbonates were deposited on the proximal part of the carbonate ramp. The establishment of a regional sequence analysis is based on the investigation of seismic profiles, well logs and outcrop sections. Examples of outcrop sections are interpreted in terms of sequence stratigraphy (unconformities of third- and second-order cycles, depositional geometries, systems tracts). The sequence stratigraphic interpretation of outcrop sections is based on facies analysis, interpretation of observed depositional geometries and correlation of unconformities and marine flooding surfaces through the basin. A biostratigraphic framework is established based on ammonites, inoceramids, planktonic and benthic foraminifera. As a result, a regional sequence stratigraphic cycle chart is presented and compared with published global cycle charts. The correlation of the regional cycle chart with published cycle charts is good. In the Cenomanian and Turonian, several sequence boundaries in the BCB are shifted by up to one biozone compared with the global chart. Some type 1 boundaries of the standard chart are only type 2 in the BCB. Important type 1 boundaries in the BCB are: top Geslinianum Zone with a 100 m lowstand wedge at the basis of the sequence (sequence boundary 92.2) ; base Petrocoriense Zone with a 250 m shallowing-upwards lowstand wedge at the basis (sequence boundary 89.2); and within the Syrtale Zone (sequence boundary 85.0).The Campanian-Maastrichtian sequence record is strongly disturbed by local compressive tectonics. Several sequences are recognizable and can be correlated with the global cycle chart. Correlation is hampered by the low biostratigraphic resolution in the western basin part. Subsidence analysis of several sections of the Upper Cretaceous of the BCB and its interpretation in the regional tectonic context leads to a discussion of the causes of the observed cyclicity. A regional eustatic curve is presented for the Upper Cretaceous of the BCB. Stage and substage names were used according Code-Committee (1977). Correspondence to: K.-U. Gräfe  相似文献   

14.
INTRODUCTIONSeqUenCestratigraphyisderivedfromseismicstratigl'aphyanditSconCeptShaveholargelyappliedtosill~ticsetting(e.g.passivemargin,I'alnP,groWth--faulting,activemarginandnonmarinesettings).InrecentyearS,thestudyofseqUenCestratigraphyhasdlawnagreatattentionfromgeologistSovertheworld.Carbonaterocksareimportantcomponentsofthesedimentaryrecord,beingmajorresouras(e.g.salt,potash,~),containinghydrOCarbon"serves,andyieldingawealthofpaleoclilnaticandpaleo--enviromnentalinfonnation~r,1991…  相似文献   

15.
江苏无锡嵩山下三叠统层序地层研究   总被引:1,自引:0,他引:1  
无锡嵩山下三叠统碳酸盐浅滩相剖面在中下扬子区具有特殊性和代表性。碳酸盐滨岸浅滩相剖面不仅最灵敏地记录了海平面变迁历史,而且具有独特的副层序结构和特殊的层序识别和研究方法,在层序地层研究中占有重要地位。借助于与微古地理相结合的副层序分析方法,在嵩山下三叠统露头剖面上共识别出3个2类三级层序,并分别讨论了各层序的发育特点和识别分析方法。  相似文献   

16.
通过对各类层序界面的识别,以沉积特征、副层序和体系域与结构转换面等层序分析,进行露头层序地层学研究,将湘西北慈利—大庸地区台缘斜坡相区上震旦统—下寒武统划分为11个Ⅲ级层序,其中上震旦统7个、下寒武统4个,主要是Ⅱ型层序。在区域层序地层对比、分析的基础上初步讨论了露头层序地层分析中存在的问题。  相似文献   

17.
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   

18.
碳酸盐层序地层应考虑碳酸盐"加工厂"、气候条件、构造背景、沉降速率、与陆地连接情况和底质类型等多种因素。碳酸盐层序地层模式在大多数情况下有别于Vail的碎屑岩层序地层模式,并且气候条件是一个值得多加考虑的因素。通过不同相区碳酸盐层序地层的划分,笔者建立了研究区上震旦统碳酸盐层序地层模式,即陵山沱期为缓坡背景碳酸盐层序地层模式,灯影期为碳酸盐台地(初始)背景层序地层模式。在高水位体系域中识别出早期高水位体系域和晚期高水位体系域。已识别出浅潮下和环潮坪两种不同类型的副层序旋回。通过层序地层分析,笔者认为陡山沱底部的白云岩属于低水位楔。  相似文献   

19.
根据海相层序地层理论和研究方法,通过对四川北部广元地区早、中三叠世沉积地层露头剖面的详细研究。划分出1个二级层序和6个三级层序。根据沉积层序和体系域的演化特征,编制了相对海平面变化曲线。通过区内沉积层序的划分对比,初步建立了广元地区早、中三叠世海相地层的层序地层格架。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号