西准噶尔前陆盆地二叠纪火山—沉积序列与盆地演化耦合

本文探讨了西准噶尔前陆盆地二叠系序界面属性及层序的内部构成,识别并标定了６类层序界面：消截角度不整合、削截不整合、削蚀不整合、削蚀上超不整合、侵蚀上超不整合和上超界面,在此研究的基础上,二叠系被划分为６个三级层序。建立了区内二叠纪火山－沉积盆地演化的序列模型。下二叠统的４个三级层序是火山沉积盆地演化的结果,与前陆盆地早期残余海的演化耦合;中、上二叠统发育的两个三级层序的时空堆叠与前陆盆地晚期地演化     

前陆盆地构造活动的层序地层响应

前陆盆地位于造山带前缘与相邻克拉通之间 ,是在挤压的地球动力学背景下形成的一种逆冲挠曲沉降盆地。近年来国内外大量的研究表明 ,前陆盆地的构造活动 ,如逆冲作用、基底隆升、不同构造带特定的沉降过程等对层序界面、层序叠置样式、体系域发育演化等起着主导性的控制作用。沉积盆地等时地层格架的建立首先依赖于各种级别的不整合及其相应的整合界面的存在。在前陆盆地中主要的不整合层序界面往往是构造逆冲作用或构造与海平面变化叠加作用的结果。Ｗａｎｇｏｎｅｒ等 ( 1995)的研究表明 ,美国ＢｏｏｋＣｌｉｆｆｓ前陆盆地的主要层序界面…     

四川盆地上三叠统构造层序划分及盆地演化

晚三叠世是四川盆地演化的重要时期。根据野外露头、钻井和地震资料,运用构造层序地层学的思路和方法,对四川盆地上三叠统层序界面、层序划分和层序特征进行深入研究,并建立层序地层格架。研究表明,四川盆地上三叠统可识别出4个层序界面:1)上三叠统与中、下三叠统之间的区域性构造不整合面;2)须二段与小塘子组的分界面;3)须三段与须四段之间的次级构造不整合面;4)三叠系与侏罗系之间的区域性构造不整合面。根据层序界面的发育情况,将研究区划分为3个构造层序,每个层序以最大湖泛面为界,划分为盆地扩张体系域(BE)和盆地收缩体系域(BW)2个体系域。晚三叠世四川盆地的演化主要是川西前陆盆地的演化,其中TS1为边缘前陆盆地演化阶段;TS2为川西前陆盆地形成阶段,龙门山逆冲推覆体开始逆冲推覆;TS3为川西前陆盆地发展阶段,受安县运动的影响,龙门山逆冲褶皱成山,使得整个四川盆地进入了陆相沉积环境。构造运动是控制晚三叠世四川盆地演化的重要因素。     

前陆盆地挠曲沉降正演模型的设计与实现——以库车古近纪陆内前陆坳陷沉降分析为例

本文以二维薄板弹性挠曲模型为基础,对模型进行简化和参数优化选取,并在VC++6.0环境下采用Windows视窗设计,实现了前陆盆地挠曲沉降的正演模拟系统.应用这一系统模拟分析了库车古近纪-新近纪前陆盆地的挠曲沉降过程.模拟结果表明,库车古近纪-新近纪前陆盆地的沉降曲线总体呈上凸型,具有典型前陆盆地沉降的特点,根据沉降速率变化可以把整个沉降过程分为四个部分,分别对应盆地的四个构造层序发育阶段,每一阶段呈不同的沉降特征,相邻两阶段之间存在一盆地回弹隆升、逆冲构造活动终止期,盆地遭受广泛剥蚀形成两个构造层序之间的不整合界面.正演模拟通过将沉降过程时间离散,精细设定不同时间段的构造负载,能够精细恢复前陆盆地的沉降过程和演化.     

前陆盆地层序地层学研究简介

前陆盆地层序地层学是将层序地层学理论应用于构造活动的前陆盆地分析的一个特例。前陆盆地三级层序成因并非受全球统一的海平面变化控制，而是与盆缘造山带区域本报特约记者运动、盆内沉积作用和相对海平面变化的联合作用有关，代表了前陆分地一个成盆期的不同发育阶段。层序界面是相对海平面下降和区域构造隆的联合作用面。在盆地演化的不对称沉降阶充填阶段，邻造山带区为低水位浊积扇沉积层序；远离造山带区，低水位体系域不发育     

合肥盆地侏罗系高精度层序地层格架研究

以合肥盆地侏罗系高精度层序地层研究为基础,对其层序地层构成及格架特征进行了精细研究,结果表明合肥盆地在侏罗纪时期为一前陆盆地.从侏罗系充填沉积中识别出7个主要的等时界面,并据界面的性质和级别划分出1个构造层序、3个层序组和6个层序,且各层序的沉积坡折分布、层序界面和单元的形成及其时空展布、演化明显受秦岭大别冲断-逆冲带自南向北的逆冲推覆作用所形成的前陆盆地构造沉降单元控制.     

西准噶尔界山前陆盆地晚期层序地层模式及其应用

西准噶尔界山前陆盆地从晚石炭世到侏罗纪的发育与演化可划分为两个时期:前陆盆地早期(C_3—P)和晚期(T—J),后者为陆相沉积。本文对前陆盆地晚期的成生机制及其演化进行了定性研究与探索,并建立了盆地生长序列模式和建立了三叠—侏罗纪前陆盆地的层序地层模式。阐述了陆相压陷盆地Ⅰ、Ⅱ型层序界面的标型特征以及前陆盆地晚期沉积体系域和湖水面升降曲线图版用于油气储集空间的预测;并建立了油气预测的储集层序格局模型。     

沙海槽前陆盆地热流变结构

为了研究南沙海槽前陆盆地深部岩石圈的热力学性质,在前人所做的地质与地球物理研究工作的基础上,结合各种岩石热力学流变参数,采用有限元分析方法,计算了现今构造逆冲之后和中中新世一全新世逆冲过程活跃时两种状态下的深部岩石圈二维温度场和流变结构.模拟计算表明,南沙海槽前陆盆地地幔热流贡献达60％～70％,大地热流受深部地幔控制...     

前陆盆地层序地层学研究中的几个问题

用层序地层学理论和工作方法来研究聚敛型活动大陆边缘的前陆盆地沉积地层时应力求使用术语上的统一,使用一级（旋回）层序、二级（旋回）层序、三级（旋回）层序等,每一级别的（旋回）层序可以划分低水位体系域、海（水）进体系域及高水位体系域、海（洪）泛面等。层序级别的划分以持续的时限为标准。各级别的层序界面以不整合面或沉积间断面或与之相应的整合面为标志。前陆盆地可容空间的变化主要受控于构造作用和全球海平面变化（假定物源供给稳定）。在造山构造活跃期,前陆挠曲作用占主导地位;在构造期后（构造宁静期）,全球海平面变化主要控制可容空间。这两种因素都以不同内容和形式在沉积层序中得到响应。通过详细的岩石学、沉积学、地层学以及各沉积区（前陆盆地即前渊、前隆和隆后盆地）剖面的区域对比研究,并与“标准”的全球海平面变化曲线图进行对比,可以区分出二者对前陆盆地形成、发育、演化的不同影响。     

库车前陆盆地古近系露头层序地层学

应用露头层序地层学基本原理和方法,在新疆库车前陆盆地古近系各种层序界面露头标志分析的基础上,探讨了该区三级层序、层序区域对比的基本特征以及层序发育的盆缘背景.研究表明:古近纪库车前陆盆地充填整体为一个二级层序,并进一步划分为8个三级层序;盆地基底的东、西分块是造成古近系充填层序纵向发育不协调的深部原因;通过沉积体系类型及演化与盆缘背景、构造活动的响应关系分析,推论了库车前陆盆地楔顶带的存在;楔顶带的发育抑制了构造活动期源于造山带的物源供给,使前陆盆地前渊带的沉积物供给速率趋于稳定.     

青藏高原东缘新生代构造层序与构造事件

新生代龙门山前盆地和盐源盆地是青藏高原东缘龙门山－锦屏山冲断带内及前缘地区发育和保存最好的新生代沉积盆地，本次以地层不整合面和ESR测年资料为主要依据，将该区新生代构造地层序列划分为5个构造层序，即TS1（65－55Ma)、TS2(40-50Ma)、TS3（23－16Ma)、TS4(4．7-1.6Ma)和TS5（0．74－0Ma)，据此将青藏高原东缘新生代构造变形和隆升事件划分为5期，其中TS1与喜马拉雅地体和拉萨地体拼合事件相关，TS2与印亚碰撞事件相关，TS3与青藏高原第一次隆升事件相关，TS4与青藏高原第二次隆升事件相关，TS5与青藏高原第三次隆升事件相关。     

Sea-level fluctuations on the northern shelf of the Eastern Paratethys in the Oligocene-Neogene

Sea-level fluctuations in the terminal Eocene, Oligocene, and Neogene of the Eastern Paratethys are quantitatively assessed on the basis of facies and old coastlines traced on the northern platform shelf, levels of river valley incisions, and the study of seismic profiles. The first data massif allows the characterization and correlation of transgression stages in the history of the Eastern Paratethys. The greatest transgressions fall within the first half of the Late Eocene, mid-Early Oligocene, initial Late Oligocene, initial Early Miocene, the initial Tchokrakian, Karaganian and Sarmatian in the Middle Miocene, the middle and late Sarmatian and early Pontian in the Late Miocene, and the Akchagylian in the Caspian basin of the Pliocene. In contrast, the greatest incisions of northern rivers running from the platform allow us to establish the time and extent of the main declines in the base levels of the erosion. Maximal incisions date back to the terminal Eocene-initial Oligocene, terminal Solenovian time in the terminal Rupelian, the terminal Maikop in the Early Miocene, the terminal Sarmatian and middle Pontian in the Late Miocene, and the Early Pliocene in the Caspian basin. Large regressions also formed unconformity surfaces, traced on seismic profiles as erosion boundaries of several orders. The surfaces are confined to the Eocene/Oligocene boundary, middle and late Maikop, Sarmatian/Meotian boundary, middle Pontian, and terminal Miocene-initial Pliocene, as well as being traced even in the most deep-water basins. The synthesis of these data suggests a preliminary version for the curve of transgression-regression cyclicity. Its correlation with the eustatic curve shows their similarity only in the lower part-prior to the initial Middle Miocene, when Paratethys became a semi-closed basin.     

南海南沙海域沉积盆地构造演化与油气成藏规律

据钻井、地震剖面、区域地质及磁异常条带分析解释,南沙海域及其邻区的主要沉积盆地的形成演化受裂谷起始不整合面和破裂不整合面分隔,可分为前裂谷期、裂谷期和后裂谷期3个构造阶段。大中型油气藏相关数据的统计表明,南沙海域及邻区大中型油气藏的成藏要素和油气田发育受构造阶段控制。(1)烃源岩发育具有分期、分区特征,礼乐盆地发育前裂谷期、裂谷1幕烃源岩;万安、曾母、西北巴拉望盆地发育裂谷2幕烃源岩,文莱-沙巴盆地发育后裂谷期烃源岩。(2)储层发育具有分期、分带特征,表现为外带老(裂谷2幕)、内带新(后裂谷期)。(3)圈闭类型包括构造、岩性地层圈闭及构造-岩性地层等因素形成的复合圈闭,大致具有内带以地层圈闭为主,外带以构造圈闭为主的特征。(4)大中型油气田分布具有外带砂岩富油气、内带碳酸盐岩富气特点。(5)南沙海域及邻区发育两个后裂谷期主含油气区,即东部巴兰三角洲砂岩背斜油气区和西部卢卡尼亚碳酸盐台地气区。其中,大中型气田的成藏要素组合为裂谷2幕烃源岩、后裂谷期碳酸盐岩储层和地层圈闭;大中型油气田则为后裂谷期烃源岩、砂岩储层和背斜圈闭。     

西太平洋782A钻孔新生代的有孔虫

大洋钻探工程” 1 2 5航次的 782 A钻孔位于西太平洋菲律宾海东北部 ,井深 4 76.8m。基底为安山岩 ,上覆盖层为中始新统—更新统的沉积层 ,其中保存有低丰度的有孔虫。自下而上可划分出 8个浮游有孔虫带。由于出现 Catapsydrax dissimilis,C.stainforthi为 N5 、N6 带的带化石 ,表明本钻孔存在早中新世的地层。同时由于缺失浮游有孔虫带 P1 5 — P1 6 下部 ,N3上部—N4,N7—N1 1 带的带化石 ,说明在中始新世与晚始新世之间、晚渐新世与早中新世之间、早中新世与中中新世之间存在 3个沉积间断。钻孔中的有孔虫标志本区当时处于温暖亚热带环境。根据不同时期温度的变化 ,可划分出 5个阶段 ,包括 3个偏暖时期和 2个温凉时期。     

南海陆缘盆地构造演化与烃源岩特征

受近南北向扩张机制控制,南海陆缘盆地或凹陷多呈NE向带状展布,总体上具有“南三北三”平行排列、外窄内宽的特点。新生代发生的4次重要区域构造运动具有穿时性,共发育3期盆地破裂不整合面,分别是早渐新世与晚渐新世之间、古近纪与新近纪之间、中中新世与晚中新世之间;由东往西,盆地破裂不整合面的时代逐渐变新。受构造运动与海平面升降影响,南海海域发育湖相、海陆过渡相和陆源海相3类烃源岩。由南北两侧向中央海盆,烃源岩类型由湖相逐渐过渡到海陆过渡相与陆源海相;从东向西,盆地主力烃源岩层位逐渐变新,由始新统-渐新统逐渐过渡到渐新统-中新统。南海海域烃源岩的分布规律与盆地破裂不整面存在密切关系:破裂不整合面形成早（早渐新世与晚渐新世之间）的盆地,主力烃源岩形成早（始新统湖相烃源岩）;反之,破裂不整合面形成晚（中中新世与晚中新世之间）的盆地,则烃源岩形成晚（渐新统-中新统海陆过渡相到陆源海相烃源岩）。     

中新生代辽河盆地区域应力场变化及其成因

中新生代辽河盆地的形成和发展受控于多期区域应力场变化。对构造现象、火山活动、层序充填型式等多种实际资料的分析表明：辽河盆地经历了侏罗纪末－白垩纪早期、古新世中后期、始新世中后期、中新世等右旋张扭应力场作用阶段，以及白垩纪晚期－古新世初期、始新世早中期、渐新世、上新世以来等左旋压扭应力场作用阶段。区域应力场变化可以用地球自转速度变化引起的岩石圈板块活动及触发的深部过程来解释，亦与先期构造形迹和盆地边界条件有关。不同区域应力场的转化不仅导致了盆地演化的旋回性，也为辽河盆地及其邻区中新生代多套含油气层系的形成奠定了物质基础。     

Late Cretaceous to early Miocene deposits of the Carpathian foreland basin in southern Moravia

 The Late Cretaceous to Early Miocene strata of the Carpathian foreland basin in southern Moravia (Czech Republic) are represented by a variety of facies which reflects the evolution of the foreland depositional system. However, because of the intensive deformation and tectonic displacement and the lack of diagnostic fossils the stratigraphic correlation and paleogeographic interpretation of these strata are difficult and often controversial. In order to better correlate and to integrate them into a broader Alpine–Carpathian foreland depositional system, these discontinuous and fragmentary strata have been related to four major tectonic and depositional events: (a) formation of the Carpathian foreland basin in Late Cretaceous which followed the subduction of Tethys and subsequent deformation of the Inner Alps-Carpathians; (b) Middle to Late Eocene transgression over the European foreland and the Carpathian fold belt accompanied by deepening of the foreland basin and deposition of organic-rich Menilitic Formation; (c) Late Oligocene to Early Miocene (Egerian) uplifting and deformation of inner zones of the Carpathian flysch belt and deposition of Krosno-type flysch in the foreland basin; and (d) Early Miocene (Eggenburgian) marine transgression and formation of late orogenic and postorogenic molasse-type foreland basin in the foreland. These four principal events and corresponding depositional sequences are recognized throughout the region and can be used as a framework for regional correlation within the Alpine–Carpathian foreland basin. Received: 18 August 1998 / Accepted: 9 June 1999     

中生代羌塘前陆盆地充填序列及演化过程

中生代羌塘前陆盆地位于青藏高原巨型造山带内 ,夹于金沙江缝合带与班公湖—怒江缝合带之间 ,是一个与两侧缝合带逆冲作用相关的沉积盆地 ,由羌北盆地 (对应于金沙江缝合带 )、羌南盆地 (对应于班公湖—怒江缝合带 )和中央隆起带构成 ,其中中央隆起是北部前陆盆地和南部前陆盆地共有的前陆隆起 ,显示为对称型复合前陆盆地 ;该盆地形成于晚三叠世 ,并持续发育至早白垩世 ,盆地中充填了巨厚的同构造期的复理石和磨拉石 ,具有总体向上变粗变浅的充填序列 ,以不整合面可将其划分为 5个由顶底不整合面限制的构造层序 ,其中晚三叠世诺利期构造层序对应于金沙江缝合带主碰撞期 ,晚三叠世瑞替期构造层序对应于金沙江缝合带碰撞闭合后冲断抬升 ,早侏罗世构造层序对应于班公湖—怒江缝合带初始逆冲推覆 ,中侏罗世—早白垩世构造层序对应于班公湖—怒江缝合带主碰撞期 ,中白垩世构造层序为班公湖—怒江缝合带碰撞闭合后冲断抬升与金沙江缝合带冲断抬升的产物 ,为中生代羌塘盆地关闭后的磨拉石建造     

Late Pliocene–Quaternary tectonics in the frontal part of the SE Carpathians: Insights from tectonic geomorphology

The Romanian East Carpathians display large-scale heterogeneities along the mountain belt, unusual foredeep geometries, significant post-collisional and neotectonic activity, and major variations in topography, mostly developed in the aftermath of late Miocene (Sarmatian; 11 Ma) subduction/underthrusting and continental collision between the East European/Scythian/Moesian foreland and the inner Carpathians Tisza-Dacia unit. In particular, the SE corner of the arcuate orogenic belt represents the place of still active large-scale differential vertical movements between the uplifting mountain chain and the subsiding Focşani foredeep basin. In this key area, we have analysed the configuration of the present day landforms and the drainage patterns in order to quantify the amplitude, timing and kinematics of these post-collisional late Pliocene–Quaternary vertical movements. A river network is incising in the upstream a high topography consisting of the external Carpathians nappes and the Pliocene–Lower Pleistocene sediments of the foreland. Further eastwards in the downstream, this network is cross-cutting a low topography consisting of the Middle Pleistocene–Holocene sediments of the foreland. Geological observations and well-preserved geomorphic features demonstrate a complex succession of geological structures. The late Pliocene–Holocene tectonic evolution is generally characterised by coeval uplift in the mountain chain and subsidence in the foreland. At a more detailed scale, these vertical movements took place in pulses of accelerated motion, with laterally variable amplitude both in space and in time. After a first late Pliocene uplifting period, subsidence took place during the Earliest Pleistocene resulting in a basal Quaternary unconformity. This was followed by two, quantifiable periods of increased uplift, which affected the studied area at the transition between the Carpathians orogen and the Focşani foreland basin in the late Early Pleistocene and the late Middle to late Pleistocene. Both large-scale deformation events affected the western Focşani basin flank, tilting the entire structure with 9° during the late Early Pleistocene and uplifted it as a block during the early Late Pleistocene. The late Early Pleistocene tilting resulted in 750 m uplift near the frontal monocline and by extrapolation in a presumed 3000 m uplift near the central parts of the Carpathians. The late Middle to late Pleistocene cumulative uplift reaches 250 m and correlates with a contemporaneous progradation of the uplifted areas towards the Focşani Basin. The uplifting events are separated by a second Quaternary unconformity. On the whole, the late Pliocene–Quaternary evolution of the Carpathians orogen/Focşani basin structure indicate large-scale differential uplift during the latest stages of a continuous post-collisional orogenic evolution.