150 Million year history of North China Craton disruption preserved in Mesozoic sediments of the Ordos basin

ABSTRACT

The Ordos Basin, situated in the western part of the North China Craton, preserves the 150-million-year history of North China Craton disruption. Those sedimentary sources from Late Triassic to early Middle Jurassic are controlled by the southern Qinling orogenic belt and northern Yinshan orogenic belt. The Middle and Late Jurassic deposits are received from south, north, east, and west of the Ordos Basin. The Cretaceous deposits are composed of aeolian deposits, probably derived from the plateau to the east. The Ordos Basin records four stages of volcanism in the Mesozoic–Late Triassic (230–220 Ma), Early Jurassic (176 Ma), Middle Jurassic (161 Ma), and Early Cretaceous (132 Ma). Late Triassic and Early Jurassic tuff develop in the southern part of the Ordos Basin, Middle Jurassic in the northeastern part, while Early Cretaceous volcanic rocks have a banding distribution along the eastern part. Mesozoic tectonic evolution can be divided into five stages according to sedimentary and volcanic records: Late Triassic extension in a N–S direction (230–220 Ma), Late Triassic compression in a N–S direction (220–210 Ma), Late Triassic–Early Jurassic–Middle Jurassic extension in a N–S direction (210–168 Ma), Late Jurassic–Early Cretaceous compression in both N–S and E–W directions (168–136 Ma), and Early Cretaceous extension in a NE–SW direction (136–132 Ma).     

Latest Triassic to Early Jurassic Thrusting and Exhumation in the Southern Ordos Basin,North China: Evidence from LA‐ICP‐MS‐based Apatite Fission Track Thermochronology

The contractional structures in the southern Ordos Basin recorded critical evidence for the interaction between Ordos Basin and Qinling Orogenic Collage. In this study, we performed apatite fission track(AFT) thermochronology to unravel the timing of thrusting and exhumation for the Laolongshan-Shengrenqiao Fault(LSF) in the southern Ordos Basin. The AFT ages from opposite sides of the LSF reveal a significant latest Triassic to Early Jurassic time-temperature discontinuity across this structure. Thermal modeling reveals at the latest Triassic to Early Jurassic, a ~50°C difference in temperature between opposite sides of the LSF currently exposed at the surface. This discontinuity is best interpreted by an episode of thrusting and exhumation of the LSF with ~1.7 km of net vertical displacement during the latest Triassic to Early Jurassic. These results, when combined with earlier thermochronological studies, stratigraphic contact relationship and tectono-sedimentary evolution, suggest that the southern Ordos Basin experienced coeval intense tectonic contraction and developed a north-vergent fold-and-thrust belt. Moreover, the southern Ordos Basin experienced a multi-stage differential exhumation during Mesozoic, including the latest Triassic to Early Jurassic and Late Jurassic to earliest Cretaceous thrust-driven exhumation as well as the Late Cretaceous overall exhumation. Specifically, the two thrust-driven exhumation events were related to tectonic stress propagation derived from the latest Triassic to Early Jurassic continued compression from Qinling Orogenic Collage and the Late Jurassic to earliest Cretaceous intracontinental orogeny of Qinling Orogenic Collage, respectively. By contrast, the Late Cretaceous overall exhumation event was related to the collision of an exotic terrain with the eastern margin of continental China at ~100 Ma.     

Segmentation and inversion of the Hangjinqi fault zone,the northern Ordos basin (North China)

This paper deals with the segmentation and inversion of the Hangjinqi fault zone (HFZ), which is the dominant structure in the northern part of the Ordos basin in North China. HFZ was reactivated during the Late Triassic and obliquely inverted during the Middle Jurassic shortening. Subsurface geological mapping and structural analysis were carried out to determine the segmentation and kinematic history of the deformation. The HFZ was a left-stepping fault zone and was made up of three segments: the Porjianghaizi fault (PF), Wulanjilinmiao fault (WF) and Sanyanjing fault (SF), which are separated by two relay ramps. Two distinct phases can be identified in its structural evolution: (1) during the Late Triassic compressional deformation, the HFZ was characterized by shortening and thrusting to the north; and (2) During the Middle Jurassic phase the HFZ was oblique to the extensional fault trends, the reverse faults were reactivated as dextral strike-slip faults as a result of transtensional inversion. The inversion ratio of the HFZ indicates an increase in deformational degree from east to west over the whole region. The first deformation stage resulted from the N–S compression between the South China and North China plates during the Late Triassic. The second deformation stage of compression was related to the west-northwestward subduction of the paleo-Pacific plate during the Middle Jurassic. In the Jurassic deformation framework, the HFZ may be interpreted as an accommodation structure parallel to the Yanshan–Yinshan orogenic belt developed in the northern Ordos area.     

鄂尔多斯盆地构造沉降特征及对盆地成因的启示

构造沉降作为盆地成因研究中的重要组成部分,对其特征进行分析有助于盆地成因的解析。本次通过对鄂尔多斯盆地内5口典型探井的多期不整合所代表的的剥蚀厚度进行恢复,结合去压实矫正模型以及平均密度、平均古水深等参数的确定,较为精确地刻画出了鄂尔多斯盆地不同构造单元自早寒武世至今的构造沉降特征,同时结合裂谷盆地瞬时拉张模型、裂后热坳陷模型以及前陆盆地挠曲模型对构造沉降曲线进行了模拟,对盆地成因进行分析。鄂尔多斯盆地中寒武世—中生代末期主要由早古生代沉降旋回、二叠—三叠纪沉降旋回与侏罗—白垩纪沉降旋回组成。其中岩石圈热冷却作用引起的沉降贯穿全地质时期。早古生代沉降旋回中,中寒武世的加速沉降主要体现在盆地南部,沉降机制为岩石圈伸展减薄,中奥陶世马家期为全盆地尺度的加速沉降,沉降机制仍为岩石圈伸展减薄。二叠—三叠纪沉降旋回中,晚二叠世—早-中三叠世为该旋回的加速沉降期,该期加速沉降具有多幕裂陷的特征。侏罗—白垩纪沉降旋回中,中侏罗世盆地南部处于缓慢沉降期,沉降机制为岩石圈热冷却作用,晚侏罗世—早白垩世,除伊盟隆起,盆地整体处于加速沉降期,沉降机制为前陆盆地引起的挠曲沉降。     

Changes of Late Mesozoic Tectonic Regimes around the Ordos Basin (North China) and their Geodynamic Implications

A synthesis is given in this paper on late Mesozoic deformation pattern in the zones around the Ordos Basin based on lithostratigraphic and structural analyses. A relative chronology of the late Mesozoic tectonic stress evolution was established from the field analyses of fault kinematics and constrained by stratigraphic contact relationships. The results show alternation of tectonic compressional and extensional regimes. The Ordos Basin and its surroundings were in weak N-S to NNE-SSW extension during the Early to Middle Jurassic, which reactivated E-W-trending basement fractures. The tectonic regime changed to a multi-directional compressional one during the Late Jurassic, which resulted in crustal shortening deformation along the marginal zones of the Ordos Basin. Then it changed to an extensional one during the Early Cretaceous, which rifted the western, northwestern and southeastern margins of the Ordos Basin. A NW-SE compression occurred during the Late Cretaceous and caused the termination of sedimentation and uplift of the Ordos Basin. This phased evolution of the late Mesozoic tectonic stress regimes and associated deformation pattern around the Ordos Basin best records the changes in regional geodynamic settings in East Asia, from the Early to Middle Jurassic post-orogenic extension following the Triassic collision between the North and South China Blocks, to the Late Jurassic multi-directional compressions produced by synchronous convergence of the three plates (the Siberian Plate to the north, Paleo-Pacific Plate to the east and Lhasa Block to the west) towards the East Asian continent. Early Cretaceous extension might be the response to collapse and lithospheric thinning of the North China Craton.     

燕山东段下辽河地区中新生代盆山构造演化

笔者通过分析燕山东段-下辽河地区的前中生代构造背景和中新生代盆山构造演化认为,该区中新生代的构造演化过程是在前中生代华北克拉通岩石图基础上发育起来的克拉通内(陆内或板内)盆山构造与挤压构造的交替演化过程,经历了早-中三叠世、晚三叠世-早侏罗世、中-晚侏罗世、白垩纪、新生代5个盆山构造演化阶段和中三叠世末、早侏罗世末、晚侏罗世末和白垩纪末、老第三纪末5期挤压作用。每次挤压作用都使得早期盆地萎缩或消亡,造成早期盆地反转。中-晚侏罗世、白垩纪和新生代三个阶段的伸展作用形成中-晚侏罗世断陷盆地、白垩纪断陷盆地和新生代裂谷盆地。在这一构造演化过程中,挤压作用和伸展作用交替出现,挤压构造和伸展构造间互发育。      

Migration of Depocenters and Accumulation Centers and its Indication of Subsidence Centers in the Mesozoic Ordos Basin

Based on the integrated study of structure attributions and characteristics of the original basin in combination with lithology and lithofacies, sedimentary provenance analysis and thickness distribution of the Mesozoic Ordos Basin, it is demonstrated that the depocenters migrated counterclockwise from southeast to the north and then to the southwest from the Middle-Late Triassic to the Early Cretaceous. There were no unified and larger-scale accumulation centers except several small isolated accumulation centers before the Early Cretaceous. The reasons why belts of relatively thick strata were well developed in the western basin in several stages are that this area is near the west boundary of the original Ordos Basin, there was abundant sediment supply and the hydrodynamic effect was strong. Therefore, they stand for local accumulation centers. Until the Early Cretaceous, depocenters, accumulation centers and subsidence centers were superposed as an entity in the southwest part of the Ordos Basin. Up to the end of the Middle Jurassic, there still appeared a paleogeographic and paleostructural higher-in-west and lower-in-east framework in the residual basin to the west of the Yellow River. The depocenters of the Ordos Basin from the Middle–Late Triassic to the Middle Jurassic were superposed consistently. The relatively high thermal maturation of Mesozoic and Paleozoic strata in the depocenters and their neighborhood suggest active deep effects in these areas. Generally, superposition of depocenters in several periods and their consistency with high thermal evolution areas reveal the control of subsidence processes. Therefore, depocenters may represent the positions of the subsidence centers. The subsidence centers (or depocenters) are located in the south of the large-scale cratonic Ordos Basin. This is associated with flexural subsidence of the foreland, resulting from the strong convergence and orogenic activity contemporaneous with the Qinling orogeny.     

运用流体包裹体确定鄂尔多斯盆地上古生界油气成藏期次和时期

对鄂尔多斯盆地上古生界68口井110块流体包裹体样品的荧光观察,60口井75块样品的显微测温、测盐等系统分析结果表明,该区上古生界砂岩储层发生过6期热流体活动,均与油气成藏有关,并以第2～6期的天然气成藏为主.结合埋藏史分析可知,油气成藏分别发生在距今220～190 Ma(T3中期-J1中期)、190～150 Ma(J1中期-J2中期)、150～130 Ma(J2中期-J2末期)、130～113 Ma(J2末期-K1中早期)、113～98 Ma(K1中早期-K1中晚期)、98～72 Ma(K1中晚期-K1末期),并认为早侏罗世中期-中侏罗世末期、中侏罗世末期-早白垩世末期是鄂尔多斯盆地上古生界天然气的主要成藏时期.     

三塘湖盆地构造演化与油气聚集

三塘湖盆地处于西伯利亚板块南缘,早石炭世晚期,盆地褶皱基底形成;晚石炭世早期,总体处于碰撞期后伸展构造环境;晚石炭世晚期,洋壳消亡,断陷收缩与整体抬升,形成剥蚀不整合.早二叠世,进入陆内前陆盆地演化阶段;中二叠世,盆地进入推覆体前缘前陆盆地发育期;晚二叠世,构造褶皱回返,前陆盆地消失;三叠纪晚期至侏罗纪中期,进入统一坳...     

鄂尔多斯盆地西南地区蓟县系古地温演化历史及岩浆热事件的影响

深层油气成藏机理研究的首要前提是要明确烃源岩的热演化历史,这对区域油气勘探潜力的评价有着重要的指导意义。鄂尔多斯盆地西南缘蓟县系烃源岩在中生代以来的热演化史有何特征,是否受早白垩世岩浆热作用的影响,影响程度如何等问题的不明确,制约着人们对该地区中元古界烃源岩的生烃潜力的认识及进一步勘探开发的思路。通过对安口—铜城地区出露的三叠系、侏罗系及铜城岩体进行磷灰石裂变径迹、磷灰石/锆石(U-Th)/He测试,结合镜质组反射率数据,分别恢复了该地区沉积岩在中三叠世以来和侵入岩在早白垩世以来的冷却历史,结合岩浆岩体的空间分布特征和泥页岩镜质组反射率,估算蓟县系烃源岩古地温。热年代学模拟表明,蓟县系烃源岩自中生代以来先后经历了三叠纪—侏罗纪的正常埋深增温,达到了生烃温度门限,自早白垩世约130～110 Ma开始冷却,其中个别样品表现为自始新世中期至45 Ma微弱加速冷却,中新世晚期至8 Ma以来快速冷却。研究表明,中晚侏罗世是鄂尔多斯盆地西南缘蓟县系生烃的关键时期,烃源岩处于主生油温度范围,之后的早白垩世晚期岩浆侵入事件的热作用范围有限,对蓟县系烃源岩古地温的影响仅发生在局部地区。鄂尔多斯盆地西南缘...     

鄂尔多斯盆地中生代地层剥蚀量估算及其地质意义

盆地演化中地层的沉积与剥蚀及盆地的历史构造形态变动是盆地分析及其矿产富集的重要影响因素。本文考虑到盆地西部白垩系的声波时差资料的分段性和估算中生代三叠纪以来抬升剥蚀事件强度所需选择合理方法的重要性,采用钻井分层资料“点连线,线线相交闭合”方式,应用以地层对比为主的方法估算了三叠纪以来4期地层抬升并遭受剥蚀的剥蚀量。估算结果发现,白垩纪末期为三叠纪以来最强烈一期全盆抬升剥蚀事件,三叠纪末期、中侏罗世和侏罗纪末期等3期剥蚀事件相对较弱。剥蚀强度分布与盆地演化模拟结果表明,盆地自三叠纪以来的构造变动表现为一掀斜过程;对盆地三叠系油气生成、运聚的影响分析认为,三叠系烃源岩在晚侏罗世前已生烃,掀斜构造演化过程使油气运移指向盆地东部及东南地区。     

Detrital zircon geochronology analysis of the Late Mesozoic deposition in the Turpan‐Hami basin: Implications for the uplift history of the Eastern Tian Shan,north‐western China

Analysing the provenance changes of synorogenic sediments in the Turpan‐Hami basin by detrital zircon geochronology is an efficient tool to examine the uplift and erosion history of the easternmost Tian Shan. We present detrital zircon U‐Pb analysis from nine samples that were collected within marginal lacustrine Middle‐Late Jurassic and aeolian‐fluvial Early Cretaceous strata in the basin. Middle‐Early Jurassic (159–172 Ma) zircons deriving from the southern Junggar dominated the Middle Jurassic sample from the western Turpan‐Hami basin, whereas Permian‐Carboniferous (270–330 Ma) zircons from the Bogda mountains were dominant in the Late Jurassic to Early Cretaceous samples. Devonian‐Silurian (400–420 Ma) and Triassic (235–259 Ma) zircons from the Jueluotage and Harlik mountains constituted the subordinate age groups in the Late Jurassic and Early Cretaceous samples from the eastern basin respectively. These provenance transitions provide evidence for uplift of the Bogda mountains in the Late Jurassic and the Harlik mountains since the Early Cretaceous.     

燕山东段～下辽河地区中新生代断裂演化与构造期次

通过对燕山东段～下辽河盆地中新生代断裂演化分析,认为中新生代该区共经历了中三叠世末,早侏罗世末,晚侏罗世末,白垩纪末和老第三纪末５期挤压作用。每期挤压作用都形成相应的挤压构造形迹,使得早期盆地萎缩或消亡,或对早期盆地进行改造使其反转。此外,该区还曾经历了中晚侏罗世,白垩纪和新生代３个明显的伸展作用阶段,形成中晚侏罗世断裂盆地,白垩纪断陷盆地和新生代裂谷盆地,构造演化过程中挤压作用和伸展作用交替出现     

The tectonics and stages of the geological history of the Yenisei–Khatanga Basin and the conjugate Taimyr Orogen

A new interpretation of the seismic profile series for the Taimyr Orogen and the Yenisei–Khatanga Basin is given in terms of their tectonics and geological history. The tectonics and tectonostratigraphy of the Yenisei–Khatanga and the Khatanga–Lena basins are considered. In the Late Vendian and Early Paleozoic, a passive continental margin and postrift shelf basin existed in Taimyr and the Yenisei–Khatanga Basin. From the Early Carboniferous to the Mid-Permian, the North and Central Taimyr zones were involved in orogeny. The Late Paleozoic foredeep was formed in the contemporary South Taimyr Zone. In the Middle to Late Triassic, a new orogeny took place in the large territory of Taimyr and the Noril’sk district of the Siberian Platform. A synorogenic foredeep has been recognized for the first time close to the Yenisei–Khatanga Basin. In the Jurassic and Early Cretaceous, this basin was subsided under transpressional conditions. Thereby, anticlinal swells were formed from the Callovian to the Aptian. Their growth continued in the Cenozoic. The Taimyr Orogen underwent tectonic reactivation and apparently right-lateral transpression from Carboniferous to Cenozoic.     

Decoding Provenance and Tectonothermal Events by Detrital Zircon Fission‐Track and U‐Pb Double Dating: A Case of the Southern Ordos Basin

Multi-dating on the same detrital grains allows for determining multiple different geo-thermochronological ages simultaneously and thus could provide more details about regional tectonics. In this paper, we carried out detrital zircon fission-track and U-Pb double dating on the Permian-Middle Triassic sediments from the southern Ordos Basin to decipher the tectonic information archived in the sediments of intracratonic basins. The detrital zircon U-Pb ages and fission-track ages, together with lag time analyses, indicate that the Permian-Middle Triassic sediments in the southern Ordos Basin are characterized by multiple provenances. The crystalline basement of the North China Craton (NCC) and recycled materials from pre-Permian sediments that were ultimately sourced from the basement of the NCC are the primary provenance, while the Permian magmatites in the northern margin of NCC and Early Paleozoic crystalline rocks in Qinling Orogenic Collage act as minor provenance. In addition, the detrital zircon fission-track age peaks reveal four major tectonothermal events, including the Late Triassic-Early Jurassic post-depositional tectonothermal event and three other tectonothermal events associated with source terrains. The Late Triassic-Early Jurassic (225–179 Ma) tectonothermal event was closely related to the upwelling of deep material and energy beneath the southwestern Ordos Basin due to the coeval northward subduction of the Yangze Block and the following collision of the Yangze Block and the NCC. The Mid-Late Permian (275–263 Ma) tectonothermal event was associated with coeval denudation in the northern part of the NCC and North Qinling terrane, resulting from the subduction of the Paleo-Asian Ocean and Tethys Ocean toward the NCC. The Late Devonian-early Late Carboniferous (348±33 Ma) tectonothermal event corresponded the long-term denudation in the hinterland and periphery of the NCC because of the arc-continent collisions in the northern and southern margins of the NCC. The Late Neoproterozoic (813–565 Ma) tectonothermal event was associated with formation of the Great Unconformity within the NCC and may be causally related to the Rodinia supercontinent breakup driven by a large-scale mantle upwelling.     

鄂尔多斯盆地中生代构造演化特征及油气分布

从地球动力学背景分析了鄂尔多斯盆地中生代构造演化特征,按构造演化序列将中生代盆地演化分为早-中三叠世盆地格架奠定期、晚三叠世盆地生油岩形成期、早-中侏罗世构造稳定期、晚侏罗世生排烃高峰期、早白垩世盆地整体抬升期及晚白垩世盆地消亡期等6个阶段.并指出中生代盆地构造演化各阶段对油气源的形成、油气聚集,以及对油气圈闭成藏等油气分布规律均有不同程度的影响及控制作用.     

准噶尔盆地陆梁地区复式油气成藏系统初探

准噶尔盆地陆梁油田的发现表明盆地腹部具有复式油气成藏系统特征,形成多源、多藏和多期次的混源现象。该区可划分为玛湖凹陷—环玛湖东斜坡油气成藏子系统、盆1井西凹陷—石南油田油气成藏子系统及盆1井西凹陷—陆梁油田油气成藏子系统。前者中,烃源灶为玛湖凹陷的风城组,成藏时期分别为晚三叠世及中侏罗世末期,成藏通道为不整合面及扇状砂体,主要形成扇体和古潜山油气藏。盆1井西凹陷—石南油田油气成藏子系统中,烃源灶主要为盆1井西凹陷的风城组,成藏时期分别为早白垩世及古近纪末期,成藏通道主要为断层及不整合面,具有阶梯状成藏特征。盆1井西凹陷—陆梁油田油气成藏子系统中,烃源灶主要为盆1井西凹陷的乌尔禾组,成藏时期分别为中侏罗世末期—早白垩世及古近纪末期,成藏通道主要为断层、不整合面及连通砂体,具有环状成藏特征。各子系统形成的原油特征也有着较大差异。各成藏子系统的分布基本受盆地的构造形态及烃源灶控制,即:玛湖凹陷—环玛湖东斜坡油气成藏子系统相对比较独立,盆1井西凹陷—陆梁油田油气成藏子系统是盆1井西凹陷—石南油田油气成藏子系统的延续与发展。断层和不整合面构成的空间输导网络为各子系统的成藏创造了有利条件。     

Palynological evidence for Jurassic strata in the Panagarh area, West Bengal, India

The Rajmahal Traps were discovered in the Panagarh area, West Bengal, during the exploration for coal resources. A Gondwana succession was found beneath the traps, consisting of the Early Cretaceous Intratrappean Rajmahal Formation, the Early Triassic Panchet Formation and the Late Permian coal-bearing Raniganj Formation. The present palynological study was aimed at confirming the age of the Panchet Formation. As a result of this study it has been found that Jurassic sediments are also included in the Panchet Formation. The study has revealed that the Panchet Formation, defined on a lithological basis, is a time-transgressive unit extending from the Early Triassic to the Late Jurassic, with a phase of non-deposition between the Middle Triassic and Middle Jurassic.     

我国腐植煤的还原性质及其与沉积环境的关系

一、不同还原性腐植煤的基本特征在研究华北聚煤区东部晚古生代太原组（C₃）和山西组（P₁1）煤性质差别及显微特征的基础上,作者认为除煤岩成分和变质程度外,还存在着影响煤质的第三个成因因素--还原性质。     

Sedimentary response to the paleogeographic and tectonic evolution of the southern North China Craton during the late Paleozoic and Mesozoic

With the aim of constraining the influence of the surrounding plates on the Late Paleozoic–Mesozoic paleogeographic and tectonic evolution of the southern North China Craton (NCC), we undertook new U–Pb and Hf isotope data for detrital zircons obtained from ten samples of upper Paleozoic to Mesozoic sediments in the Luoyang Basin and Dengfeng area. Samples of upper Paleozoic to Mesozoic strata were obtained from the Taiyuan, Xiashihezi, Shangshihezi, Shiqianfeng, Ermaying, Shangyoufangzhuang, Upper Jurassic unnamed, and Lower Cretaceous unnamed formations (from oldest to youngest). On the basis of the youngest zircon ages, combined with the age-diagnostic fossils, and volcanic interlayer, we propose that the Taiyuan Formation (youngest zircon age of 439 Ma) formed during the Late Carboniferous and Early Permian, the Xiashihezi Formation (276 Ma) during the Early Permian, the Shangshihezi (376 Ma) and Shiqianfeng (279 Ma) formations during the Middle–Late Permian, the Ermaying Group (232 Ma) and Shangyoufangzhuang Formation (230 and 210 Ma) during the Late Triassic, the Jurassic unnamed formation (154 Ma) during the Late Jurassic, and the Cretaceous unnamed formation (158 Ma) during the Early Cretaceous. These results, together with previously published data, indicate that: (1) Upper Carboniferous–Lower Permian sandstones were sourced from the Northern Qinling Orogen (NQO); (2) Lower Permian sandstones were formed mainly from material derived from the Yinshan–Yanshan Orogenic Belt (YYOB) on the northern margin of the NCC with only minor material from the NQO; (3) Middle–Upper Permian sandstones were derived primarily from the NQO, with only a small contribution from the YYOB; (4) Upper Triassic sandstones were sourced mainly from the YYOB and contain only minor amounts of material from the NQO; (5) Upper Jurassic sandstones were derived from material sourced from the NQO; and (6) Lower Cretaceous conglomerate was formed mainly from recycled earlier detritus.The provenance shift in the Upper Carboniferous–Mesozoic sediments within the study area indicates that the YYOB was strongly uplifted twice, first in relation to subduction of the Paleo-Asian Ocean Plate beneath the northern margin of the NCC during the Early Permian, and subsequently in relation to collision between the southern Mongolian Plate and the northern margin of the NCC during the Late Triassic. The three episodes of tectonic uplift of the NQO were probably related to collision between the North and South Qinling terranes, northward subduction of the Mianlue Ocean Plate, and collision between the Yangtze Craton and the southern margin of the NCC during the Late Carboniferous–Early Permian, Middle–Late Permian, and Late Jurassic, respectively. The southern margin of the central NCC was rapidly uplifted and eroded during the Early Cretaceous.