燕山构造带西段千家店盆地生长构造与生长地层

Izanagi板块在晚中生代向NW前进式俯冲于欧亚板块东部之下,诱发形成了燕山构造带一系列挤压构造,然而构造的具体形成时间以及弥散分布于燕山构造带的山间盆地的控盆构造属性、构造活动与沉积作用之间的相互关系依然存在着较大的争议.本文基于对北京北部千家店盆地上侏罗统-下白垩统土城子组的沉积作用、物源及盆缘、盆内构造的精细研究,认为:千家店盆地西缘发育断展褶皱型生长构造与生长地层,土城子组第二段顶部和第三段地层在盆地西缘生长,它们受控于翼部旋转模式的断展褶皱作用;千家店盆地内发育的两条小型逆冲断层,均表现为盆地基底下马岭组逆冲于土城子组地层之上,可能控制了断弯褶皱型生长地层的发育;盆地"源-汇"过程分析表明,尚义-平泉断裂上盘基底地层为千家店盆地晚侏罗世-早白垩世早期地层的主要物源区;断展褶皱型生长地层底界面处火山岩获得的最年轻的一组锆石206Pb/238U加权平均年龄为(140.8±2.4)Ma,它可能代表了断展褶皱型生长构造活动的起始时间.千家店盆地断展褶皱型生长构造和生长地层的发现,证明了千家店盆地早白垩世早期是受控于褶皱-逆冲作用的山间挠曲盆地.近E-W向的尚义-平泉断裂与NE向的千家店逆冲断层和盆内的两条逆冲断层可能构成一个统一的右行走滑式逆冲构造系统,共同控制了千家店盆地土城子组的沉积,其构造作用可能与侏罗纪至早白垩世初Izanagi板块向NW的前进式平板俯冲有关.     

南海北部新生代盆地基底结构及构造属性

基于南海北部钻井资料、华南沿海地质特征、覆盖珠江口盆地和琼东南盆地的地震长剖面解释,将南海北部盆地基底结构划分为前震旦系、震旦系-下古生界、上古生界和中生界4个构造层,论述了各个构造层的分布范围和分布规律,揭示了各个构造层的构造属性.南海北部盆地广泛分布前震旦纪结晶基底,它与华夏地块前震旦纪结晶基底联为一体,组成更大规模的陆块——华夏-南海北部陆块.震旦系-下古生界广泛分布于南海北部,是华南加里东褶皱带向海域的自然延伸,沉积物来源于东海南部-台湾、中西沙、云开古隆起和一些小的基底隆起区,南海北部加里东褶皱带与华南相连,组成范围更为辽阔的褶皱带.上古生界构造层分布在北部湾盆地和台西南盆地基底中,由稳定的陆表海沉积所组成,珠江口盆地和琼东南盆地基底在晚古生代属于古隆起,缺失上古生界构造层.中晚侏罗世-白垩纪地层分布及沉积环境具有东西分异特征,台西南盆地基底中发育有海相和海陆交互相沉积,火山活动不明显;珠江口盆地东部基底以海相和海陆过渡相为主,火山活动较强烈;珠江口盆地西部和琼东南盆地基底以早白垩世陆相火山-沉积为主;北部湾、莺歌海盆地基底以上白垩统陆相红色碎屑岩为主.中生界基底中北东向花岗质火山-侵入杂岩、火山-沉积盆地、褶皱、断裂与华南沿海陆域具有相似的时空分布、地质特征及构造属性,它们属于同一岩浆-沉积-构造体系,反映了晚中生代构造层形成于活动大陆边缘背景中.在基底结构及构造属性研究的基础上,编制了南海北部盆地基底不同时期古地理图.     

南海南北陆缘中生代地层—构造特征及碰撞造山

为进一步深入了解南海地区中生代构造演化过程.本文对南海南北陆缘的中生代地层进行了分析对比,在此基础上挑选了南北陆缘处的两条地震测线07ns-6和97301进行了详细的解释分析.通过地震剖面的解释发现,南海北部和南部(礼乐地块)地震剖面中的中生代地层均显示有褶皱—冲断构造发育.据此推断,研究区在中生代先后经历了洋—陆俯冲活动、陆 陆碰撞造山运动及中生代晚期开始的造山带的塌陷.提出南海地区中生代晚期的“古双峰笔架碰撞造山带”概念.     

冀北张家口地区同构造沉积过程及其与褶皱-逆冲作用耦合

"燕山运动"年代和燕山构造带侏罗纪的构造性质仍存在着争论.燕山山间盆地沉积地层记录了燕山运动的活动历史及盆地构造性质,开展盆-山系统同构造沉积及其构造控制关系研究,准确确定地层年代,重新建立年代地层格架是进一步揭示燕山侏罗纪至早白垩世构造变形机制、变形年代的有效途径.本文通过对燕山西段与太行山北段交接部位的冀北张家口地区褶皱-逆冲带与山间沉积盆地的构造和沉积结合研究表明,研究区沉积盆地中发育的所谓"侏罗纪地层"可能为晚三叠世-早侏罗世、中侏罗世和晚侏罗世-早白垩世早期地层;受生长褶皱-逆冲构造控制,在褶皱-逆冲带边缘形成褶皱前渊型、逆冲前渊型、断展褶皱型、断弯褶皱型及断弯褶皱与断展褶皱复合型生长地层;重建的由褶皱-逆冲带与挠曲盆地构成的晚三叠世-早侏罗世、中侏罗世、晚侏罗世和早白垩世早期的"源-汇"系统反映了燕山运动在研究区起始于中侏罗世;在晚侏罗世晚期-早白垩世早期至少发生了3次褶皱-逆冲事件,形成了基底卷入式褶皱-逆冲构造和小型山间挠曲盆地;基底卷入式褶皱-逆冲带与挠曲盆地"对"的自东向西迁移,可能受控于西太平洋"平板式"前进俯冲作用.     

中国近海前新生代残留盆地初探

中国近海沉积盆地按形成时代可以划分为新生代盆地和前新生代盆地。新生代陆相碎屑岩断陷盆地有良好的油气前景,而古生代还有广泛海相碳酸盐岩分布地区,只要它们经受中生代挤压,改造后还能保留下来,就具有巨大的油气潜力。初步分析中国近海的油气勘探资料及大地构造演化史表明,陆内断坳盆地下伏以古生代碳酸盐岩为主的残留盆地。而陆缘盆地并不是寻找古生代残留盆地的场所。但在台西南盆地,珠江口盆地潮汕坳陷发育海相中生代盆     

渤海湾盆地区燕山期构造特征与盆地转型

以各种地震资料的分析解释、构造解析为基础,对燕山期渤海湾盆地区构造特征与盆地转型过程进行了研究.结果表明:燕山早期渤海湾盆地区以挤压褶皱及逆冲断裂发育为主,在太行山以东、盐山-歧口-兰聊断裂以西地区主要展布方向为NE和NNE向,整体具有西强东弱的特征,在盐山-歧口-兰聊断裂以东的济阳坳陷区,以NW(W)向的逆冲断层发育为主;燕山中期研究区以伸展构造发育为主,在太行山以东、盐山-歧口-兰聊断裂带以西地区断层展布方向主要为N(N)E向,盐山-歧口-兰聊断裂带以东、郯庐断裂带以西、张家口-蓬莱断裂带以南地区主要发育NW(W)向负反转断层,张家口-蓬莱断裂带以北地区以N(N)E向断裂发育为主;燕山晚期以正反转断层及新生逆冲断层发育为主.燕山期渤海湾盆地区发生了三次重要的盆地转型,燕山早期由印支期的挤压隆升剥蚀转型为山间坳陷盆地,燕山中期由山间坳陷转型为强烈的陆内断陷盆地,燕山晚期由陆内断陷盆地转为隆起区遭受剥蚀.区域构造背景的转变是燕山期渤海湾盆地区转型的主控因素,不同构造期盆地的叠加改造造成了研究区前第三系油气地质条件的复杂性和多样性.     

南海北部东沙运动的构造特征及动力学机制探讨

南海北部陆缘在南海扩张结束后发生了一次重要的构造运动—东沙运动.因前人对其研究较少,目前对其发生时间、影响范围和形成机制等都存在较大的争议.通过对东沙海区及其邻区新近纪地层二维、三维地震资料的详细解释,确定了东沙运动发生在晚中新世晚期,并在晚中新世末/早上新世初(5.5Ma)停止活动.东沙运动主要波及东沙隆起和潮汕坳陷地区,构造上主要表现为断块升降,其中隆起区沉积物遭受剥蚀,造成中新世及部分上新世地层的缺失.这次运动还形成了大量次级的NW-NWW向张性、张扭性断裂,构造运动整体上具有东强西弱的特点.东沙运动可能与新近纪以来菲律宾海板块持续向NWW方向运动导致的吕宋岛弧与欧亚大陆在9～6Ma期间开始发生的弧陆碰撞有关.同时,由于南海向马尼拉海沟下的俯冲及洋壳的冷却沉降作用,南海北部陆缘处于拉张环境,岩浆底侵到下地壳底部形成高速层,破坏了该区域的地壳均衡,从而造成上部地壳的隆升.     

合肥盆地和郯庐断裂带南段深部地球物理特征研究

根据重、磁、电、震资料联合反演和综合解释,研究了合肥盆地和郯庐断裂带南段深部结构特征和构造样式. 合肥盆地呈现深部印支面以下为逆冲断层、以上为张性正断层的构造样式,盆地构造反转发生在晚侏罗世,早白垩世是裂陷盆地形成的主要时期,早白垩世晚期合肥盆地发生构造反转,发育冲逆、冲推覆构造. 郯庐断裂带南段表现为“上正下逆”的构造变形样式和正花状构造特征,并经历了复杂的挤压走滑-引张正断层变形过程.     

穿越东沙隆起和潮汕坳陷的OBS广角地震剖面

为了探明南海中北部陆缘深部地壳结构,使用2D射线追踪正演和反演方法,拟合了一条南海中北部陆缘的OBS广角地震剖面(OBS2006-3).该剖面穿越东沙隆起和潮汕坳陷,长319 km,NNW-SSE走向,共投放海底地震仪14台.速度结构模型表明:潮汕坳陷存在巨厚的中生代沉积,最大厚度达到8 km,速度从顶部的4.4 km...     

酒泉盆地群热演化史恢复及其对比研究

酒泉盆地群是由两期不同性质、不同世代盆地叠加而成的 .晚侏罗纪-早白垩世为拉张断陷盆地 ,第三纪以来为挤压坳陷盆地 .酒泉盆地群现今地温梯度及大地热流值都较低 ,地温梯度主要在 2 51- 3 0 0℃ /1 0 0m之间 ,大地热流值在 50- 57mW /m2 之间 .酒泉盆地群中生代晚期为拉张断陷 ,古地温梯度高 ,可达 3 75- 4 50℃ /1 0 0m ,新生代以来地温梯度逐渐降低 ,而花海盆地、酒西盆地石北凹陷沉降幅度小 ,古地温高于今地温 .下白垩统烃源岩热演化程度受古地温控制 .主生烃期仅有一次 ,为早白垩世晚期 .酒西盆地青西凹陷、酒东盆地营尔凹陷在新生代以来大幅度沉降 ,下白垩统烃源岩热演化程度受现今地温控制 .主生烃期有两次 ,一次为早白垩世晚期 ,另一次为晚第三纪以来 ,且以晚第三纪以来为主 .不同盆地及同一盆地不同构造单元由于构造热演化史的不同 ,主生烃期及油气勘探前景明显不同 .     

Texture and tectonic attribute of Cenozoic basin basement in the northern South China Sea

Based on the drilling data,the geological characteristics of the coast in South China,and the interpretation of the long seismic profiles covering the Pearl River Mouth Basin and southeastern Hainan Basin,the basin basement in the northern South China Sea is divided into four structural layers,namely,Pre-Sinian crystalline basement,Sinian-lower Paleozoic,upper Paleozoic,and Mesozoic structural layers.This paper discusses the distribution range and law and reveals the tectonic attribute of each structural layer.The Pre-Sinian crystalline basement is distributed in the northern South China Sea,which is linked to the Pre-Sinian crystalline basement of the Cathaysian Block and together they constitute a larger-scale continental block—the Cathaysian-northern South China Sea continental block.The Sinian-lower Paleozoic structural layer is distributed in the northern South China Sea,which is the natural extension of the Caledonian fold belt in South China to the sea area.The sediments are derived from southern East China Sea-Taiwan,Zhongsha-Xisha islands and Yunkai ancient uplifts,and some small basement uplifts.The Caledonian fold belt in the northern South China Sea is linked with that in South China and they constitute the wider fold belt.The upper Paleozoic structural layer is unevenly distributed in the northern South China.In the basement of Beibu Gulf Basin and southwestern Taiwan Basin,the structural layer is composed of the stable epicontinental sea deposit.The distribution areas in the Pearl River Mouth Basin and the southeastern Hainan Basin belong to ancient uplifts in the late Paleozoic,lacking the upper Paleozoic structural layers.The stratigraphic distribution and sedimentary environment in Middle-Late Jurassic to Cretaceous are characteristic of differentiation in the east and the west.The marine,paralic deposit is well developed in the basin basement of southwestern Taiwan but the volcanic activity is not obvious.The marine and paralic facies deposit is distributed in the eastern Pearl River Mouth Basin basement and the volcanic activity is stronger.The continental facies volcano-sediment in the Early Cretaceous is distributed in the basement of the western Pearl River Mouth Basin and Southeastern Hainan Basin.The Upper Cretaceous red continental facies clastic rocks are distributed in the Beibu Gulf Basin and Yinggehai Basin.The NE direction granitic volcanic-intrusive complex,volcano-sedimentary basin,fold and fault in Mesozoic basement have the similar temporal and spatial distribution,geological feature,and tectonic attribute with the coastal land in South China,and they belong to the same magma-deposition-tectonic system,which demonstrates that the late Mesozoic structural layer was formed in the background of active continental margin.Based on the analysis of basement structure and the study on tectonic attribute,the paleogeographic map of the basin basement in different periods in the northern South China Sea is compiled.     

Mesozoic basin evolution and tectonic mechanism in Yanshan, China

The Mesozoic basins in Yanshan, China underwent several important tectonic transformations, including changes from a pre-Late Triassic marginal cratonic basin to a Late Triassic-Late Jurassic flexural basin and then to a late Late Jurassic-Early Cretaceous rift basin. In response to two violent intraplate deformation at Late Triassic and Late Jurassic, coarse fluvial depositional systems in Xingshikou and Tuchengzi Formations were deposited in front of thrust belts. Controlled by transform and extension faulting, fan deltas and lacustrine systems were deposited in Early Cretaceous basins. The composition of clastic debris in Late Triassic and Late Jurassic flexural basins respectively represents unroofing processes from Proterozoic to Archean and from early deposited, overlying pyroclastic rocks to basement rocks in provenance areas. Restored protobasins were gradually migrated toward nearly NEE to EW-trending from Early Jurassic to early Late Jurassic. The Early Cretaceous basins with a NNE-trending crossed over early-formed basins. The Early-Late Jurassic and Early Cretaceous basins were respectively controlled by different tectonic mechanisms.     

南海共轭大陆边缘构造属性的综合地球物理研究

利用南海最新的重磁资料,在岩石物性分析和全海域分带变倾角化极磁异常反演磁性基底分布的基础上,选择6条典型剖面拟合反演其密度与磁性结构,在此基础上进行了深部结构的对比分析.反演中尽可能以海底地震仪探测数据(OBS)、多道地震等结果作为约束,其中FF'剖面层速度分析是利用“南海大陆边缘动力学及油气资源潜力”973项目200...     

Mesozoic paleogeography and tectonic evolution of South China Sea and adjacent areas in the context of Tethyan and Paleo-Pacific interconnections

Abstract   During the Mesozoic era, the South China Sea and its environs were located at the south-eastern margin of the Eurasian continent. There has been hot debate on the influences of Tethyan and Paleo-Pacific tectonics to the Mesozoic evolution of the area. This paper compiles lithofacies maps of six time slices and discusses the paleogeographic and tectonic evolution of the area based on this compilation and other data on structural deformation and magmatism. In the Early Triassic, the Paleotethys Ocean extended eastward to the study area through the Song Da passage. Then a significant east–west differential evolution began. In the Late Triassic, the western area uplifted as a result of the collision between the Indosinian and South China blocks during the Indosinian orogeny, and the Song Da passage has closed since then. Meanwhile, a transgression of Paleo-Pacific waters occurred in the eastern and south-eastern portions of the area, forming the 'East Guangdong–North-west Borneo Sea'. In the Early Jurassic, seawater transgression was even more pronounced, resulting into the connection of this sea with the Mesotethys Ocean to the west. Large quantities of Tethyan water carrying Tethyan organisms entered the area. In the Middle Jurassic, a short-lived transgression occurred in the eastern Mesotethys and resulted in the formation of the 'Yunnan–Burma Sea'. The Late Jurassic to Early Cretaceous was the climax of the subduction of both the Mesotethys and Paleo-Pacific towards the Eurasian continent. This led to the formation of the great 'Circum South-east Asia Subduction–Accretion Zone' in the Middle or Late Cretaceous. This paper also presents various lines of evidence for a newly recognized segment of this Mesozoic subduction–accretion zone buried under Cenozoic sediments in the north-eastern South China Sea.     

南海大陆边缘动力学:科学实验与研究进展

国家重点基础研究发展计划(973)项目(2007CB411700)首次在南海南部大陆边缘及西南次海盆开展长排列大震源多道地震、海底地震仪(OBS)折射/反射地震等的综合地球物理探测,结合地质构造、地球化学、动力模拟等的综合研究,形成如下重要认识:南海海盆新生代发生了早、晚两期海底扩张.早期扩张发生于33.5～25 Ma...     

龙门山及其邻区的构造和地震活动及动力学

论述了龙门山推覆构造带、岷山隆起、成都平原和龙泉山地区的构造和地震活动，讨论了构造活动特点和演化历史，并分析了它们的形成机制和动力学问题     

Mesozoic radiolarian faunas from the northwest Ilocos Region,Luzon, Philippines and their tectonic significance

Northwestern Ilocos Norte in Luzon, Philippines, exposes cherts, peridotite and a variety of metamorphic rocks including chlorite schist, quartzo‐feldspathic schist, muscovite schist and actinolite schist. These rocks are incorporated within a tectonic mélange, the Dos Hermanos Mélange, which is thrust onto the turbidite succession of the Eocene Bangui Formation and capped by the Upper Miocene Pasuquin Limestone. The radiolarian assemblages constrain the stratigraphic range of the cherts to the uppermost Jurassic to Lower Cretaceous. Stratigraphically important species include Eucyrtidiellum pyramis (Aita), Hiscocapsa acuta (Hull), Protunuma japonicus (Matsuoka & Yao), Archeodictyomitra montisserei (Squinabol), Hiscocapsa asseni (Tan), Cryptamphorella conara (Foreman) and Pseudodictyomitra carpatica (Lozyniak). The radiolarian biostratigraphic data provide evidence for the existence of a Mesozoic basinal source from which the cherts and associated rocks were derived. Crucial to determining the origin of these rocks is their distribution and resemblance with known mélange outcrops in Central Philippines. The mélange in the northwestern Ilocos region bears similarities in terms of age and composition with those noted in the western part of the Central Philippines, particularly in the islands of Romblon, Mindoro and Panay. The existence of tectonic mélanges in the Central Philippines has been attributed to the Early to Middle Miocene arc–continent collision. This event involved the Philippine Mobile Belt and the Palawan Microcontinental Block, a terrane that drifted from the southeastern margin of mainland Asia following the opening of the South China Sea. Such arc–continent collision event could also well explain the existence of a tectonic mélange in northwestern Luzon.     

潮汕坳陷地球物理特征及油气勘探潜力

潮汕坳陷位于珠江口盆地南部,是珠江口盆地油气勘探的新领域.中生界地层特征和油气勘探潜力是目前工作重点.本文分析了潮汕坳陷区域重力、磁异常特征及地震地质规律,提出潮汕坳陷是衔接东沙群岛和西沙群岛两个构造单元的构造过渡带的观点,同时盆倾断层控制了中生界发育与分布.根据潮汕坳陷地震等地球物理特征及地质规律,结合前人研究结果,分析了该区的油气勘探潜力.