胶莱盆地及其邻区白垩纪－古新世沉积构造演化历史及其区域动力学意义

基于野外和钻孔测井资料分析、火山岩同位素年代学分析 (40Ar-39Ar and SHRIMP U-Pb)、地震剖面的构造解释、断层运动学的野外分析结果,综合研究了胶莱盆地及其邻区白垩纪－古新世沉积构造演化历史。岩性地层分析表明,胶莱断陷盆地由三套地层单元所充填：早白垩世莱阳群和青山群、晚白垩世－古新世王氏群。青山群火山岩的同位素年代学测试结果给出了该火山岩的喷发时代在120～105 Ma。地震剖面的构造解译结果揭示胶莱盆地伸展构造受到深部两个拆离构造系统控制：一个发育于盆地南部地区,拆离断面位于深部8~10 km,向南缓倾于苏鲁造山带之下;另一个拆离系统由一系列北倾的犁式断层组成、分布于宽阔的胶莱盆地北部地区,主拆离面向北倾。这两个拆离系统分别形成于早白垩世莱阳群和晚白垩世-古新世王氏群沉积阶段。通过对不同地层单元断层滑动矢量的野外测量和古构造应力场反演,以及地层时代和同位素年代学测试结果的制约,建立了白垩纪－古新世构造应力场演替的年代序列。结果表明,胶莱盆地在白垩纪-古新世之间经历了伸展－挤压应力体制的交替演化。早白垩世伸展作用经历了两个不同的阶段：早期NW-SE向伸展和晚期近W-E向伸展。在早白垩世末期至晚白垩世初期,盆地遭受NW-SE向挤压,导致了胶莱盆地的缩短变形和郯庐断裂带的左旋走滑活动。晚白垩世－古新世时期,构造应力场转变为N-S向伸展,直到古新世末期,构造应力场转换为NE－SW向挤压。胶莱盆地和沂沭裂谷系白垩纪－古新世沉积构造演化历史对华北地区岩石圈减薄过程的动力学背景提供了重要的构造地质学制约。笔者推断,早白垩世两期引张应力作用是分别对华北地区增厚地壳或岩石圈的重力垮塌和岩石圈拆沉的响应,而早白垩世末期NW-SE向挤压记录了古太平洋板块与亚洲陆缘俯冲碰撞产生的远程效应。晚白垩世-古新世的引张伸展作用完全不同于早白垩世伸展构造,它指示了沿NNE向郯庐断裂带的右旋走滑活动及其拉分作用,在动力学上受到青藏地区块体的陆－陆碰撞产生的远程效应和古太平洋板块向亚洲大陆俯冲作用的联合应力场控制。     

胶莱盆地白垩纪构造演化

胶莱盆地是位于胶东半岛的白垩纪盆地,前人对该盆地的沉积-构造演化进行了相关研究,也取得了重要进展。但是关于盆地初始形成阶段古构造应力场状态还存在一些争论。本文通过对盆地内部断层滑动矢量数据的反演及节理、同沉积断层指示意义分析,将胶莱盆地白垩纪构造演化划分为五个阶段:早白垩世早期NWW-SEE向伸展,控制了莱阳群初始沉积;莱阳群沉积末期近E-W向挤压;早白垩世晚期E-W向伸展,形成了青山群;早白垩世末期NW-SE向挤压;晚白垩世近N-S向至NNE-SSW向伸展,形成了王氏群。大量的野外现象与前人研究成果均与本文得到的盆地初始成盆阶段NWW-SEE向伸展应力场相吻合。NWW-SEE向伸展作用可能是在古太平洋板块向欧亚板块俯冲过程中,古太平洋板块后撤与苏鲁造山带后造山作用的共同作用下发生的,代表胶莱盆地形成初期,受苏鲁造山带造山后期作用的影响;而青山期伸展方向的变化可能指示盆地主要受到古太平洋板块后撤的影响。盆地在白垩纪古构造应力场的作用下,分别受到早白垩世裂谷作用与晚白垩世走滑拉分作用控制,两种作用的叠加使胶莱盆地成为一个复合型盆地。     

胶莱盆地白垩纪构造应力场与转换机制

通过对胶莱盆地断层滑动矢量的收集与测量,利用计算机程序反演了盆地白垩纪的古构造应力场演化历史,并据此将盆地的发育划分为三个伸展阶段和三个挤压反转阶段,分别为早白垩世早-中期莱阳期伸展,与造山期后应力松弛重力坍塌有关;早白垩世中-晚期青山期伸展,受早白垩纪早期以后广泛的岩石圈减薄、大陆裂陷制约;晚白垩世王氏期伸展,与郯庐断裂及牟平-即墨断裂右旋走滑有关。三期伸展之间存在构造挤压反转,最后阐明各期盆地发育的地球动力学背景。     

河西走廊平山湖盆地早白垩世构造变形期次及其碎屑锆石U-Pb年龄约束

河西走廊北部的平山湖盆地,被围限于龙首山、北大山和合黎山之间,是一个在早白垩世受南北两侧逆冲断层共同控制形成并发展的盆地。笔者通过研究盆地内下白垩统沉积特征、构造变形、生长地层以及碎屑锆石U-Pb年代学特征,划分了平山湖盆地在早白垩世的构造演化期次,并恢复其形成演化过程。盆地内发育一套由下向上总体变细的下白垩统庙沟群沉积序列,盆地内构造变形以NE-SW向挤压和近E-W向伸展为主,庙沟群上岩组的碎屑锆石最小年龄为(129.3±1.8)Ma,可能代表了地层沉积和同期地堑发育的最早时间。由此得出,在早白垩世早期发育挤压构造盆地,同构造生长地层为挤压盆地的形成与构造演化提供了时代约束;在早白垩世晚期发育伸展断陷盆地,由挤压到伸展的转换时间晚于129.3 Ma。     

湘西沅麻盆地中新生代构造变形特征及区域地质背景

沅麻盆地是叠加在雪峰造山带中段的一个中生代大规模陆相盆地,盆地中新生代断裂、褶皱发育特征尚缺乏系统、深入的研究。本文通过构造剖面测制、野外路线调查并结合区域地质资料,对沅麻盆地中新生代构造格架、褶皱和断裂的发育特征、变形序列、时代及区域构造背景等进行了详细的分析研究,取得以下主要认识和进展。(1)NNE-NE向正断裂、逆断裂和平缓褶皱(主要为向斜)组成沅麻盆地的主体构造格架,同时发育其他多组不同方向、性质的褶皱和断裂。盆地西部和中部大部以正断裂为主,形成复杂的堑-垒构造格局,褶皱变形强度低;盆地东缘因区域怀化—沅陵断裂带控制而变形强烈,以多为东倾、少量西倾的逆断裂为主,常伴有倒转紧闭褶皱。(2)中三叠世以来沅麻盆地经历多期构造变形事件:1中三叠世晚期印支运动中受区域NW—NWW向挤压而形成NE—NNE向褶皱和逆断裂;2晚三叠世—早侏罗世期间受区域SN向挤压,形成EW向褶皱和膝折;3中侏罗世晚期早燕山运动中受区域NWW—近EW向挤压,形成盆地东缘上三叠统—中侏罗统卷入的SN向和NNE向褶皱和逆断裂;4早白垩世区域NW-SE向伸展作用下形成不同规模的NE—NNE向正断裂;5晚白垩世在区域SN向伸展体制下形成EW向正断裂;6古近纪中晚期受区域NE向挤压,形成卷入白垩系及先期地层的NW向褶皱、NW向逆断裂、NEE—NE向左行走滑(或兼逆冲)断裂、NNE向右行走滑断裂、NEE向与NNE向共轭剪节理等;7古近纪末—新近纪初在区域NW向挤压下,形成最新卷入地层为白垩系的NE向褶皱、NE-NNE向逆断裂、SN向逆断裂。上述多期变形中以早白垩世NW-SE伸展形成的正断裂和古近纪末—新近纪初NW-SE向挤压形成的褶皱和逆断裂最为重要,其次为中侏罗世晚期NWW—近EW向挤压下形成的褶皱和逆断裂。(3)前人提出的沅麻盆地东部及东侧外围地区发育的王炳坡、黄金坳、潭湾、麻阳等"飞来峰"构造并不存在,所谓"飞来峰"实为向下"生根"的断夹块,组成"飞来峰"的板溪群座立于古生界和中生界之中与逆冲断裂或正断裂活动有关。     

青藏高原东北隅马衔山断裂带及周缘白垩纪—新生代沉积和构造变形历史

马衔山断裂带地处青藏高原东北隅陇中盆地的腹地, 分隔了北部的兰州盆地和南部临夏盆地, 该断裂带的变形特征记录了该地区白垩纪—新生代时期的构造演化历史。本文通过对马衔山断裂带的运动学分析并结合区域地层序列, 建立了三阶段的变形历史。第一阶段近WNW–ESE向伸展作用控制了马衔山断陷盆地的伸展断陷和早白垩世河湖相沉积, 在晚白垩世晚期—古新世早期(~80–60 Ma)在NNW–SSE向挤压作用下, 断裂发生右旋走滑活动, 盆地挤压反转。该阶段的断层活动和盆地发育的板块动力主要来自亚洲大陆南部和东部陆缘新特提斯洋—古太平洋俯冲汇聚。第二阶段表征为古近纪(~60–23 Ma)构造挤压与走滑拉分盆地的发育, 晚古新世—晚始新世地层主要分布在西宁盆地、兰州盆地、马衔山东南段等区域, 在马衔山地区这期挤压应力方向为NNE向, 是印度—欧亚大陆碰撞的远程响应。第三阶段为中新世(~23 Ma–)时期。早期(~23–13 Ma)马衔山北缘断裂以正断层活动为主, 控制了断裂带东南段中新世红黏土沉积, 引张应力方向为NNW–SSE。中新世晚期(~13 Ma起)以来, 构造应力体制转变为ENE–WSW挤压, 其造成马衔山地区周缘山系的快速隆升。     

六盘山盆地形成和改造历史及构造应力场演化

六盘山盆地夹于鄂尔多斯地块、青藏地块和阿拉善地块之间,在中国大地构造体系中处于独特的构造位置。基于野外变形分析与断层滑动矢量构造应力场反演,初步确定了六盘山盆地形成与构造演化历史。结果表明,六盘山盆地主要经历了早白垩世成盆过程和后期改造过程2个大的阶段。早白垩世早期,受到区域近E-W向引张应力作用而发生断陷,盆内沉积了一套巨厚的河湖相六盘山群;早白垩世晚期在NW-SE向挤压下,断陷盆地发生构造反转,局部地区褶皱回返,六盘山群发生不同程度的断裂和褶皱变形,继而盆地开始了长期的隆升剥蚀作用。晚新生代,受到印度—欧亚大陆碰撞产生的远程效应,六盘山盆地先后经历了NE-SW向和近E-W向挤压应力作用,盆地发生了强烈的褶皱和断裂变形,六盘山快速隆起。六盘山盆地构造应力场演化历史不仅为研究周缘地块的运动学和动力学提供构造地质依据,也对盆地油气勘探具有指导意义。     

渤海湾地区的中生代盆地构造概论

根据 1∶5 0万渤海湾新生代盆地区基岩地质图揭示的残留中生代地层的分布及构造变形特征 ,渤海湾地区的中生代盆地可以分为 5期。早—中三叠世、晚三叠世盆地为克拉通内部大型坳陷盆地 ,其中晚三叠世盆地仅分布在渤海湾西南部地区。早—中侏罗世盆地分布于印支运动形成的向斜坳陷核部 ,属于压陷挠曲型盆地。晚侏罗世—早白垩世盆地分布广泛 ,属于裂陷盆地 ;晚白垩世盆地属于后裂陷阶段的坳陷盆地。这些盆地受印支运动、燕山运动影响而发生反转。印支运动在渤海湾地区的东、西部的表现有明显差异。西部变形弱、以近EW向宽缓褶皱变形为主 ,东部变形强、并叠加了NE向褶皱和逆冲断层变形。早燕山运动使渤海湾地区形成宽缓的大型NE向褶皱变形 ,并使早—中侏罗世盆地发生反转和逆冲断层变形 ;中、晚燕山运动基本没有在渤海湾地区形成褶皱构造变形 ,而是表现为晚侏罗—早白垩世盆地和晚白垩世盆地的区域性反转隆升。下—中侏罗统沉积之后 ,渤海湾地区的构造格局发生基本变革 ,进入以裂陷盆地为主的构造演化时期。     

大杨树盆地的构造特征及变形期次

大杨树盆地是叠置于大兴安岭造山带的东部,与松辽盆地紧邻,呈北北东向长条带状展布的中新生代断陷-坳陷型盆地。大杨树盆地经历了多期变形作用,具有以伸展构造为主、并被挤压构造和反转构造叠加的构造特征。早白垩世龙江期主要受到了NWW—SEE向的拉伸作用,形成一系列北北东向控陷犁式正断层组合,在控陷断层的上盘发育小型箕状断陷;早白垩世九峰山期,大杨树盆地受挤压作用控制,使早期形成的断陷盆地发生反转作用,形成正反转构造,同时在某些地段形成逆冲断层和断层传播褶皱;早白垩世甘河期,大杨树盆地再次受到伸展作用,形成了一系列北北东向小型断陷。早白垩世晚期(甘河期之后)—晚白垩世早期,大杨树盆地受到强烈的挤压作用,使早期控陷正断层出现正反转作用,在盆地的浅部形成大型断层传播褶皱,使大杨树盆地全面隆升遭受剥蚀。第四纪大杨树盆地具有伸展的特征,发育一系列小型伸展断陷。     

华北晚中生代构造演化过程——根据太行山北部盆地沉积记录

太行山北部地区处于燕山山脉和太行山山脉的交汇处,其侏罗纪—白垩纪叠加盆地发育过程记录了东西向盆地向北东向盆地转化过程,对刻画华北晚中生代陆内变形过程及其动力学背景具有重要意义。本文以太行山北部草沟堡盆地和招柏盆地为例,在盆地基本构造格架分析的基础上,通过详细的沉积物物源分析、盆地原型再造等沉积学方法,结合岩浆岩同位素年代学数据,提出太行山北部晚中生代构造演化过程,主要经历四个发展演化阶段,包括中侏罗世晚期近南北向构造挤压与挠曲盆地发育、晚侏罗世近南北向弱伸展作用与壳源火山喷发、晚侏罗世末期—早白垩世早期北西—南东向构造挤压与前陆盆地形成、早白垩世北西—南东向伸展作用与幔源火山作用。构造体制转变本质上是动力学体系的转变,在中晚侏罗世东亚大陆多向汇聚体系之下,太行山北部经历的多期构造叠加和盆地叠置过程折射了蒙古—鄂霍茨克构造体系向滨太平洋构造体系的转化过程。     

东至断裂带构造变形特征及其构造演化

东至断裂带是皖西南一条重要的北北东向断裂带。详细的构造解析表明,该断裂带主要经过3期构造变形,分别是发生在晚侏罗世末—早白垩世初的左行平移断层、早白垩世期间的伸展构造和晚白垩世—新生代的右行平移断层。通过断层擦痕矢量反演和断层叠加改造关系分析,认为东至断裂带及其两侧多期构造变形对应的区域应力场分别为近南北向挤压、北北西—南南东向挤压、北西—南东向伸展和近东西向挤压应力场。东至断裂带的形成和演化与郯庐断裂带相似,主要与华南与华北板块俯冲碰撞、伊泽奈崎板块和古太平洋板块向欧亚板块俯冲碰撞与弧后扩张、及印度板块向北碰撞后产生向东的构造挤出等多构造体制共同作用有关。     

Cretaceous deformation history of the middle Tan-Lu fault zone in Shandong Province, eastern China

Based on field analysis of fault-slip data from different rock units of the Cretaceous basins along the middle part of the Tan-Lu fault zone (Shandong Province, eastern China), we document polyphase tectonic stress fields and address the changes in sense of motion of the Tan-Lu fault zone during the Cretaceous. The Cretaceous deformation history of the Tan-Lu fault zone can be divided into four main stages. The first stage, during the earliest Cretaceous, was dominated by N-S extension responsible for the formation of the Jiaolai basin. We interpret this extension to be related to dextral strike-slip pull-apart opening guided by the Tan-Lu fault zone. The second stage, during the middle Early Cretaceous, was overwhelmingly rift-dominated and characterized by widespread silicic to intermediate volcanism, normal faulting and basin subsidence. It was at this stage that the Tan-Lu-parallel Yi-Shu Rift was initiated by E-W to WNW-ESE extension. The tectonic regime then changed during the late Early Cretaceous to NW-SE-oriented transpression, causing inversion of the Early Cretaceous rift basin and sinistral slip along the Tan-Lu fault zone. During the Late Cretaceous, dextral activation of the Tan-Lu fault zone resulted in pull-apart opening of the Zhucheng basin, which was subsequently deformed by NE-SW compression. This deformation chronology of the Tan-Lu fault zone and the associated Cretaceous basins allow us to constrain the regional kinematic models as related to subduction along the eastern margin of Asia, or related to collision in the Tibet region.     

Cretaceous sedimentary basins in Sichuan,SW China: Restoration of tectonic and depositional environments

This study documents sediment infill features and their responses to the tectonic evolution of the Sichuan Basin and adjacent areas. The data include a comparison of field outcrops, well drillings, inter-well correlations, seismic data, isopach maps, and the spatial evolution of sedimentary facies. We divided the evolutionary history of the Sichuan Cretaceous Basin into three stages based on the following tectonic subsidence curves: the early Early Cretaceous (145–125 Ma), late Early Cretaceous to early Late Cretaceous (125–89.8 Ma), and late Late Cretaceous (89.8–66 Ma). The basin underwent NW–SE compression with northwestward shortening in the early Early Cretaceous and was dominated by alluvial fans and fluviolacustrine sedimentary systems. The central and northern areas of the Sichuan Basin were rapidly uplifted during the late Early Cretaceous to early Late Cretaceous with southwestward tilting, which resulted in the formation of a depression, exhibited southwestward compression, and was characterized by aeolian desert and fluviolacustrine deposits. The tectonic framework is controlled by the inherited basement structure and the formation of NE mountains, which not only affected the clastic supply of the sedimentary basin but also blocked warm-wet currents from the southeast, which changed the climatic conditions in the late Late Cretaceous. The formation and evolution of Cretaceous sedimentary basins are closely related to synchronous subtle far-field tectonism and changes in climate and drainage systems. According to the analysis of the migration of the Cretaceous sedimentation centers, different basin structures formed during different periods, including periods of peripheral mountain asynchronous thrusting and regional differential uplift. Thus, the Sichuan Cretaceous sedimentary basin is recognized as a superimposed foreland basin.     

鄂西利川齐岳山高陡背斜带的古应力分析

鄂西利川地区位于湘鄂西构造带与川东构造带的过渡部位,叠加褶皱发育,地处两大构造带分界处的齐岳山高陡背斜带断裂发育。本文以利川地区褶皱和断裂为研究对象,在野外观测和分析的基础上,采用断层滑动数据反演方法,对构造应力场进行了恢复;结合区域构造演化历史,提出该区侏罗纪以来经历了五期构造应力作用,从早到晚分别为:北西-南东向挤压(J3-K1)、近东西向挤压(K1)、近南北向挤压(K1-K2)、北西-南东向引张(K2)和北东-南西向挤压(E3)。该区侏罗纪以来构造变形序列的建立,为深入认识齐岳山高陡背斜带地质灾害形成的地质背景提供了构造地质学证据。     

Detrital zircon provenance of the Wangshi and Laiyang groups of the Jiaolai basin: evidence for Early Cretaceous uplift of the Sulu orogen,Eastern China

ABSTRACT

The Late Mesozoic Jiaolai basin preserves sediment source information that can help elucidate the tectonic history of East Shandong, China. The terrestrial Wangshi and Laiyang Groups are major components of the basin succession, but are not well studied in terms of their provenance and role in basin evolution. The Early Cretaceous Laiyang Group consists primarily of fluvial and lacustrine facies siltstones and sandstones, whereas the Late Cretaceous Wangshi Group consists of reddish fluvial siltstones and sandstones with interbedded conglomerates. This study reports detrital zircon age distributions from eight sandstones collected from the two groups. Age distributions exhibited four major populations of Palaeoproterozoic (2.5–2.4 Ga), Palaeoproterozoic (1.9–1.8 Ga), Neoproterozoic (850–700 Ma), and Jurassic to Early Cretaceous (171–107 Ma) ages. We interpret a maximum depositional age of 107 Ma for the Wangshi Group and a depositional age of 121–120 Ma for the upper Laiyang Group. Age distributions indicate that the Sulu orogenic belt of the East Shandong complex served as the primary source area. Detrital zircon age data also indicate major changes in the types of source material contributed to the Laiyang and Wangshi groups. Based on these shifts, we propose a four-stage model for Early Cretaceous evolution of the Jiaolai basin. In this model, subduction of the Pacific plate and associated transform motion on the Tan-Lu fault influenced the transition from a transpressional to an extensional tectonic setting.     

中亚造山带东段西拉木伦构造带的性质与演化：来自变形和低温热年代学的约束

中亚造山带东段何时与何地关闭,从俯冲到关闭的过程以及随后的陆内演化又经历了什么主要事件,目前还存在不同认识。中亚造山带东段林西地区的蛇绿混杂岩及其周围地区的区域地质调查表明,以杏树洼蛇绿混杂岩和双井片岩为代表的西拉木伦河构造带是一个晚古生代的增生楔,在该混杂岩带中发育了典型的岩块被包裹在基质中的构造。该楔体被中、晚二叠世克德河砾岩所覆盖。增生楔中最早的近东西向构造代表了向南俯冲阶段的变形,随后继续经历向北的逆冲推覆,卷入了中、晚二叠世地层,形成了碰撞期的变形;在晚二叠世末期—三叠纪早期,蛇绿混杂岩以及上覆的克德河砾岩又经历了区域性的强烈的右行韧性剪切,并发生应变分解。晚二叠世区域性的右行韧性剪切在中亚造山带南缘普遍发育,代表了中亚造山带已经全部进入陆内环境。双井片岩也经历了与蛇绿混杂岩类似的变形事件,在增生楔下部经历变质作用,并在碰撞期抬升至地表,晚期为区域性的右行剪切。同时,结合锆石与磷灰石低温热年代学测试表明,双井片岩和蛇绿混杂岩共同经历了中、晚侏罗世源自北侧蒙古-阿霍茨克大洋关闭导致的近南北向挤压、早白垩世期间遍及东亚的区域性伸展以及晚白垩世短暂的构造反转事件。     

Meso-Cenozoic tectonic evolution of the Dangyang Basin,north-central Yangtze craton,central China

Based on detailed structural data and available tectonic chronological data from the Dangyang Basin, the authors propose that the north-central Yangtze craton experienced three stages of tectonic evolution since Late Triassic time. In the Late Triassic to Early Jurassic (T₃–J₁), due to the Indosinian orogeny, nearly N–S compression and shortening occurred, which initiated the Dangyang Basin as a foreland basin of the Qinling–Dabie orogen. During the Late Jurassic–Early Cretaceous (J₃–K₁) period, the Yanshanian intracontinental orogeny caused contemporaneous NE–SW and NW–SE shortening, which resulted in intense folding of the foreland basin; contraction formed a brush structure diverging in a SE direction and strongly converging in a NW direction around the Huangling anticline. In the Late Cretaceous to Palaeogene, the Yuan'an and Hanshui grabens were separated from other parts of the Dangyang Basin due to post-orogenic ENE–WSW extension. Finally, at the end of the Palaeogene, ENE–WSW shortening led to inversion and deformation of the grabens.