Accretionary Tectonics in the Neoproterozoic History of the Larsemann Hills and Adjacent Areas, East Antarctica

ForaPrecambriancratoncomposedofcompositeterranes,orblocks,andbelts,whichexperiencedcomplexpolyphasedeformationandmetamorphism,thefinaltectonothermaleventismoresignificantthantheearlieronesinthelightofplatetectonics,becausethefinaltectonothermaleventresultedfromamalga-mationofthecraton.Although,generally,aworkinghypothesisofpolyphasedeformationandmetamorphismiswidelyappliedtoahigh-gradeterrane,dis-cernmentofitsfinaltectonothermalepisodeisvitaltounderstandingitsgeologicalhistory.Inrecentyears,an…     

Ages and Compositions of the Precambrian High-grade Basement of the Qilian Terrane and Its Adjacent Areas

Based on geological, chronological, geochemical and Nd isotopic studies of the high-grade basement of the Qilian terrane, the authors have drawn the following main conclusions: (1) the high-grade basement of the Qilian terrane consists mainly of meta-argillo-arenaceous rocks and granites and its bulk part was formed in the period of 0.8-1.0 Ga (the Jinningian period); (2) most of the meta-argillo-arenaceous rocks and granitic rocks have strong negative Eu and Ba anomalies (Eu/Eu*= 0.47-0.71 and Ba/Ba*=0.16-0.64), with fDM and εNd(1.0 Ga) ranging from 1.87 to 2.26 Ga and from -8.54 to -4.06 respectively, showing relatively high maturity; and (3) the Jinningian granitic rocks are a typical product of continent-continent collision, being probably related to the formation of the supercontinent Rodinia. These studies, combined with the study of high-grade basement rocks near the Qilian terrane, suggest that before the Jinningian period, the Qilian-Qaidam northern-margin terrane and Dunhuang-Alxa terrane wer     

Continental- Margin Structure of Northeast China and Its Adjacent Areas

The continental margin of Northeast China and its adjacent areas is composed of two tectonic belts. The inner belt is a collage made up of fragments resulting from breakup of an old land with the north part related to the evolution of the Palaeo-Asian Ocean and the south part to the evolution of the Palaeo - Pacific Ocean. The outer belt is a Mesozoic terrane, which is a melange made up of fragments of the Late Palaeozoic to Early Mesozoic oceanic crust and the Late M esozoic trench accumulations.There existed another ocean-the Palaeo - Pacific Ocean during the period from the closing of the Palaeo-Asian Ocean to the opening of the modern Pacific Ocean or from the Devonian to Jurassic, and the ocean-floor spreading of the Palaeo - Pacific Ocean led to the formation of the above-mentioned tectonic belts. The development of the strike-slip fault system after the Late Jurassic and the formation of an epicontinental volcano -plutonic rock belt in the Late Cretaceous to Early Tertiary are attributed to the i     

Tectonic Factors Favourable for the Formation of Evaporites in the Indosinian Period in Hubei and Its Neighbouring Areas

In the Indosinian period. the climate was scorching hot and the source of seawater was ample in Hubeiand its neighbouring areas. so the basic conditions for the formation of evaporites were favourable. Under thisprerequisite. the reason why salt deposits occurring in some third-order tectonic units between the Jiangnanoldland-upwarped zone and the Dabashan upwarped zone differ in degree of development is mainly due to thetectonic factors during sedimentation. If favourable tectonic factors are present, large amounts or evaporiteswill form: on the contrary. they will not.     

Deep Structures in China and Its Adjacent Areas: Plate Tectonics and Its Metallogenic Significance

This paper proposes a new tectonic pattern of the deep-seated structures in China and its adjacent areas (including the T - A - B system of the Ryukyu Islands). This is based on studies of the gravity field and gravity inversion coupled with the summation of the most recent achievements in geophysical studies. From a plate-tectonic point of view, the metallogenic characteristics and their indications at depth, as well as relevant geophysical-geological characteristics of four tectonic environments of the Chinese continent are analysed, and a classification of composite metallogenic provinces and belts and prediction of metallogenic prospects are made. The author extends the Kunlun-Qilian-Qinling tectonic belt to the T-A-B system of the Ryukyu Islands through the NW deep boundary of the Hangzhou Bay, and also proposes the following basic views' the migration and superposition of tectonic environments led to the formation of a composite metallogenic system; the change in the tectonic environment resulted     

Tectonic Development of the Proterozoic Continental Margins in East Qinling and Adjacent Regions

The East Qinling and adjacent cratonic regions belong to two geotectonicunits,the Sinokorean Subdomain including the Sinokorean Platform and itssouthern continental margin the North Qinling Belt,and the YangtzeanSubdomain comprising the Yangtze Platform and its northern continental mar-gin the South Qinling Belt.The Qinling region may thus be subdivided into twocontinental margin belts separated from each other by the Proterozoic Qinlingmarine realm,which did not disappear until Late Triassic.The convergentcrustal consumption zone,the megasuture between the two belts,lies betweenthe Fengxian-Shangnan line in the north and the Shanyang-Xijia line in thesouth and was much deformed and displaced through Mesozoic intracratoniccollision and compression.In the northern subdomain the Lower Proterozoic is representedby protoaulacogen volcano-sediments,the inner Tiedonggou Group and theouter marginal Qinling Group,which were folded and metamorphosed in theLuliangian orogeny,a general process of aggregation and s     

Tectonic Evolution of the Basement–Sedimentary Cover System and Morhpostructural Differentiation of Sedimentary Basins

Geotectonics - The article provides geological data on the morphostructural differentiation of sedimentary basins and the results of tectonophysical and digital modeling reflecting the shape and...     

Sequence-Stratigraphic Framework from the Carboniferous to the Permian Chuanshanian Epoch in Dianqiangui Basin and Its Adjacent Areas, Southwest China

INTRODUCTION Alotofprogresshasbeenmadeinthestudyof Carboniferoussedimentologyandstratigraphyinthe Dianqianguibasinanditsadjacentareas,whichin cludethecomprehensivesummariesonchronostratigraphyandbiostratigraphybyJinetal.(2000)and Kuangetal.(1999);theoverallandsystematicsum mariesonCarboniferouslithostratigraphybyDong(1997),Yin(1997)andZhao(1996);thecompre hensivestudyonCarboniferoussedimentaryfacies andpaleogeographybyChenetal.(1994)andFeng etal.(1998)etc..AsshowninFig.1,theDian qiang…     

Structure and Evolution of Ancient and Modern Tectonic–Sedimentary Systems

Geotectonics - The article discusses the ratio of the size and spatial position of ancient and modern areas of geodynamic processes (tectonic-sedimentary systems) and the resulting geological...     

Late Paleozoic Sequence-Stratigraphic Frameworks and Sea Level Changes in Dianqiangui Basin and Its Adjacent Areas with Systematic Revision of Regional Unconformities

The formation process of the Dianqiangui basin, a special basin, occurred after the Caledonian orogeny, in the south of Guizhou, the west of Giamgxo and the southeast of Yunnan, experienced three periods:it began in the Devonian, persisted in the Carboniferous, and became fiercer in the Permian. Controlled by syndepositional fault-zones, varieties of isolated carbonate platforms, large and small, were developed in the of a deep-water basin, namely, an inter-platform ditch. And a special paleogeographical Late Paleozoic pattern marked by “platform-basin-hill-trough” was produced in both the Dianqiangui basin and its adjacent arms. Affected by regional tectonic activities and the global changes in the sea level, the platform carbonates and coal measures superimposed each other cyclically on the attached platform. The reef-building on the isolated platform and the margin of the attached platform corresponds to the development of the shale succession in the deep-water basin. All of these elementary characteristics reflect a regular and sophisticated filling sucoession of the Dianqiangui basin, a result of the dual controls of the regionally tectonic activities and the eustacy.Based on the two elementary features of the third-order sequences, i.e. the regularity of sedimentary-facies succession in space and the simultaneity of environmental changes in time, 25 third-order sequences could be discerned in the Upper Paleozoic strata in the Dianqiangui basin and its adjacent areas. On the basis of the two kinds of facies-changing surfaces and the two kinds of diachronisms in stratigraphic records, the regional Late Paleozoic sequence-sequence-stratigraphic framework in the Dianqiangui basin and its adjacent areas can be established.There are two types of facies-changing surfaces and two types of diachronisms in stratigraphic records: the static type, a result of the change in sedimentary facies in space, and the dynamic type, a remit of the change in time. These two types of facies-changing surfaces led to the generation of the two types of diachronisms: the diachronism of facies-changing surfaces that was formed by the static facies-changing surfaces, and the diachronism of punactuated surfaces that was formed by the dynamic facies-changing surfaces. The two types of facieschanging surfaces and the two types of diachronisms in stratigraphic records are the key to the establishment of the sequence-stratigraphic framework, The sequence boundaries could be divided geologically into four types:tectonic unconformity, sedimentary unconformity,drowned unconformity and their correlative surfaces,All of these four types can be further grouped into exposed punctuated surfaces and deepened punctuated surfaces,The tectonic unconformity in similar to Type Ⅰ sequence boundary,and the sedimentary unconformity is similar to Type Ⅱ sequence boundary defined by Vail et al.In terms of sequence stratigraphy,the tectonic unconformities of the Ziyun movement,the Qiangui epeirogeny and the Dongwu revolution as well as the drowned unconformity in the transitional period from the Permian to the Triassic can be systematically defined and their geological characteristics are briefly presented.     

内蒙古额济纳旗地貌特征及其构造、气候事件

根据遥感卫星影像解译及野外地质实地调查,将内蒙古额济纳旗地区的地貌单元划分为中低山区、冲—洪积平原、湖积盆地及风成地貌。根据不同地貌单元组成的沉积物年龄测定和分析,初步认为上新世—早更新世的构造抬升形成苏泊淖尔级湖积阶地;早更新世末(750±60kaBP),发生一次明显的构造抬升活动,形成东、西居延海间的台地;另一次明显的构造抬升记录发生在中更世末—晚更新世初,即149±60kaBP之后,形成黑城冲湖积台地;苏泊淖尔级阶地形成于全新世早、中期,属气候干旱湖泊萎缩形成的气候阶地,阶地沉积物中保存的古风成砂丘,表明晚更新世末—全新世早期气候一度恶化。天鹅湖湖积阶地的形成表明5000a之后一段时间,气候相对适宜;全新世中后期,气候波动强烈,1200aBP出现一次丰水期。     

内蒙古西部额济纳旗及邻区石炭系—二叠系沉积环境

为进一步研究额济纳旗及其邻区石炭系—二叠系沉积地质与盆地原型, 根据研究区的岩性、岩相建造、古生物化石、沉积演化、沉积构造等基本数据,采用野外观察与室内研究相结合的方法,对额济纳旗及其邻区石炭系—二叠系的沉积环境进行了分析。额济纳旗及其邻区石炭系—二叠系受阿拉善古陆和北西方向海浸的控制,岩性特征受石炭纪—二叠纪构造单元的控制,岩性组合为碎屑岩+碳酸盐岩+火山岩。由南向北碎屑岩粒度变细,南部以滨岸环境的碎屑岩为主,北部以浅海陆棚环境和碳酸盐台地环境为主。额济纳旗及其邻区石炭系—二叠系沉积环境对优质烃源岩和储集层的发育具有控制作用。     

内蒙古西部额济纳旗及邻区石炭系——二叠系沉积环境

为进一步研究额济纳旗及其邻区石炭系—二叠系沉积地质与盆地原型,根据研究区的岩性、岩相建造、古生物化石、沉积演化、沉积构造等基本数据,采用野外观察与室内研究相结合的方法,对额济纳旗及其邻区石炭系—二叠系的沉积环境进行了分析。额济纳旗及其邻区石炭系—二叠系受阿拉善古陆和北西方向海浸的控制,岩性特征受石炭纪—二叠纪构造单元的控制,岩性组合为碎屑岩＋碳酸盐岩＋火山岩。由南向北碎屑岩粒度变细,南部以滨岸环境的碎屑岩为主,北部以浅海陆棚环境和碳酸盐台地环境为主。额济纳旗及其邻区石炭系—二叠系沉积环境对优质烃源岩和储集层的发育具有控制作用。     

内蒙古西部额济纳旗及邻区石炭系—二叠系沉积环境

为进一步研究额济纳旗及其邻区石炭系—二叠系沉积地质与盆地原型, 根据研究区的岩性、岩相建造、古生物化石、沉积演化、沉积构造等基本数据,采用野外观察与室内研究相结合的方法,对额济纳旗及其邻区石炭系—二叠系的沉积环境进行了分析。额济纳旗及其邻区石炭系—二叠系受阿拉善古陆和北西方向海浸的控制,岩性特征受石炭纪—二叠纪构造单元的控制,岩性组合为碎屑岩+碳酸盐岩+火山岩。由南向北碎屑岩粒度变细,南部以滨岸环境的碎屑岩为主,北部以浅海陆棚环境和碳酸盐台地环境为主。额济纳旗及其邻区石炭系—二叠系沉积环境对优质烃源岩和储集层的发育具有控制作用。     

桂西地区二叠纪至白垩纪构造演化对沉积型铝土矿成矿的制约

桂西地区地处右江盆地,位于华南板块扬子陆块之上,是中国重要的铝土矿产地之一.为了探讨沉积型铝土矿对本地区晚古生代至早中生代的构造演化的响应,分析其对铝土矿成矿过程的影响,文章从矿床地质特征及地层学的角度,剖析了沉积型铝土矿赋矿地层及周边地区地层岩性记录的构造信息.结果显示,桂西沉积型铝土矿的成矿和改造过程始终受区域性构...     

中亚与邻区盆地群构造演化及含油气性

基于中亚及其邻区大地构造和盆地构造演化,利用古板块再造、地理信息软件等对中亚盆地群的构造演化及含油气性进行探讨。中亚与邻区盆地群在早古生代分属不同陆块,这些陆块于早石炭世开始汇聚,早二叠世完成拼合,形成中亚盆地群。汇聚前该区受到海西期构造影响,在中生代伸展构造和新生代挤压构造的作用下形成的众多盆地类型为叠合盆地。该区主要烃岩源发育于海西期早期和中-新生代伸展背景的裂谷事件。油气主要集中在侏罗系(41%)和石炭系(37%)中,主要的勘探目的层是碳酸盐岩、礁灰岩、膏岩和泥岩。阿姆河、费尔干纳、图尔盖和阿富汗-塔吉克等盆地的油气主要集中于前陆冲断带和凹陷断阶带。滨里海、北乌斯丘尔特和曼各什拉克等克拉通盆地油气集中于盆地边缘的隆起带和断阶带,具有自生自储特征。     

北秦岭小寨变质沉积岩系的地质特征及其构造意义

原岩恢复、沉积建造及变形变质综合研究表明,北秦岭小寨变质沉积岩系属活动陆缘性质沉积建造,形成于二郎坪弧后盆地消减俯冲带的海沟盆地-海沟斜坡环境,是古俯冲带的重要证据之一,其变形序列反映了弧后盆地构造演化过程,并与构造混杂岩、俯冲型花岗岩及高压变质带一起构成相对完整的古俯冲带标志,为探讨秦岭古生代板块构造演化提供了重要信息。     

塔里木板块周缘晚古生代以来的构造演化

塔里木板块在晚古生代以来,经历了一系列碰撞和拼合事件,受北侧哈萨克斯坦－准噶尔板块碰撞的影响,南天山石炭纪再生洋盆于早二叠世末隆起,并导致天山山前陆盆地形成。这一时期塔木西部强烈的热活动事件,反映了一次地壳开裂活动,并导致天山山前的前陆盆地形成,这一时期里木西部强烈的热活动事件,反映了一次地壳开裂活动,同时进一步推动了塔里木向天山下插的陆内俯冲活动及前陆盆地的形成,中生代时期,特提斯洋盆的活动及先     

鄂尔多斯盆地中新生代构造事件的峰值年龄及其沉积响应

通过锆石-磷灰石裂变径迹的峰值年龄与地层不整合事件的综合分析,提供了鄂尔多斯盆地中新生代构造事件的年代学约束及其沉积响应特点。印支期构造事件主要发生在230~190Ma,包含215Ma±和195Ma±两个峰值年龄,在盆地西南缘发育晚3叠世粗碎屑类磨拉石建造。燕山期构造事件主要发生在燕山中晚期的150~85Ma,包含145Ma±、120Ma±和95Ma±3个峰值年龄,在盆地西南缘发育燕山中期的芬芳河组和志丹群的粗碎屑类磨拉石建造。喜山期构造事件主要发生在65~5Ma,包含55Ma±、25Ma±和5Ma±3个峰值年龄。其中,锆石和磷灰石叠合分布的峰值年龄(145Ma±),指示了鄂尔多斯盆地中新生代的一次关键性构造变革事件。     

从新疆地学断面的成果讨论中国西北盆-山区的地壳构造演化

本文从新疆独山子-泉水沟地学断面的资料介绍了准噶尔盆地、天山、塔里木盆地和昆仑山等新疆南部不同地区的地壳结构构造,进而对中国西北盆-山地区地壳构造及演化的某些特征进行了探讨.提出:中国西部-盆山地区地壳构造运动发生的主要原因是地壳及上地幔的不均一性(包括结构构造的不均一性以及物质成分的不均一性).强调了现代盆-山构造面貌虽然是新生代的产物,但其形成从中生代就已经开始,是一个延续的历史过程;但二者又有所不同,目前的盆-山构造格局已明显不同于中生代甚至古生代的盆-山构造面貌.