塔里木西北部乌什—柯坪—巴楚地区古生代沉积—构造演化及成盆动力学背景

把柯坪断隆"还原"为塔里木板块的一部分,重塑了它与北邻的乌什地区和南邻的巴楚地区古生代 "分分""合合"的演化史,得到以下重要认识。(1)奥陶纪在乌什、柯坪和巴楚一间房地区发育以东西向的古吐木休克断层为南界的台盆; 该断层的西段后期被柯坪塔格断裂(东西走向段)迁就利用,中—东段后期因被肢解而"消失"。(2)柯坪地区最西部中泥盆世已有海相沉积,晚泥盆世—石炭纪海侵不断向东扩展;因南天山洋的消减在柯坪—阿克苏—库车一线形成横贯塔里木北缘的石炭纪隆起带,使得塔里木中—北部上泥盆统—石炭系的沉积相有清楚的空间展布规律。(3)据同位素年龄值将柯坪地区东段玄武岩的时代更正为早二叠世,强烈火成活动造成的热隆升使该地区早二叠世即出现陆相沉积;塔西北的其他地区石炭纪末—早二叠世普遍发生海侵。(4)从与南天山洋和西昆仑洋耦合演化的角度简要探讨了塔里木西北地区古生代的成盆动力学背景,认为古生代有东西向、北西向及北东向的控盆和控相断裂发育并总结了其后期演化的特点。

华北盆地三叠纪物源特征及其沉积—构造演化——来自碎屑锆石年龄的指示

华北盆地三叠纪沉积厚度大,分布广泛,其地层沉积特征很好地记录了周缘造山带或隆起区在该时期的构造演化过程。目前,前人已经对华北各地区三叠纪碎屑物源进行了大量研究,而对于物源区的认识仍存在分歧,对于盆缘地区沉积—构造演化过程的研究也相对较少。通过整理前人对华北各地区三叠纪碎屑物源研究的锆石年龄数据,并结合造山带构造演化过程和地层沉积特征,对华北盆地三叠纪碎屑物源及沉积—构造演化过程进行了整体研究。结果表明:华北北部三叠纪沉积物源均来自北缘的内蒙古隆起,锆石年龄和地层沉积特征记录了源区逐渐增强的岩浆活动和隆升过程。华北南部地区在该时期主要接受来自华北南缘二叠纪沉积盖层和北秦岭造山带的碎屑物质供给,华北南缘伴随着秦岭造山过程可能在中三叠世就已经逆冲隆升并遭受剥蚀,两者的协同演变共同控制着盆地南部沉积演化过程。鄂尔多斯盆地西北部碎屑物源主要来自阿拉善地块和北祁连造山带,西南部地区物源则主要来自盆地西南缘再旋回沉积盖层和北祁连造山带,分别为伸展和挤压状态下的内陆盆地沉积。早—中三叠世,华北盆地为统一的大型内陆沉积盆地,晚三叠世,盆地南、北缘发育沿褶皱逆冲带分布的陆内前陆盆地系统。

简评《塔里木板块周缘的沉积—构造演化》

塔里木盆地是我国最大的内陆盆地。这一巨型盆地特殊的地理位置和独特的地质背景，引起了地质学家的浓厚兴趣。１９世纪以来，就有许多国内外学者到塔里木盆地及其周缘地区进行科学考察。随着全面开展对塔里木盆地的油气普查勘探及开发工作，科技攻关不断深入，地质研究和...

塔里木盆地西部库孜贡苏地区白垩—早第三纪沉积特征及沉积环境探讨

从晚侏罗世开始,塔里木盆地西部库孜贡苏地区即已进入盆地早期发展阶段,并于早白垩世中晚期开始遭受海侵的影响,形成滨岸带沉积。晚白垩世初至早第三纪晚期,共形成了三次较大规模的海水进退沉积旋回,即库克拜组中上部—乌依塔克组、依格孜牙组—阿尔塔什组、齐姆根组—乌拉根组。其沉积环境演化特征为早白垩世山间盆地洪积扇—近海洪泛平原沉积,晚白垩世局限台地及古—始新世开阔台地—台地边缘沉积环境,渐新世时期海水逐渐退出本区。总之,本区沉积环境演化受印度板块及拉萨地块向北碰撞挤压而造成的新的山脉隆升及伴随的构造活动所控制,所反映的白垩—早第三纪海平面变化与全球海平面变化基本可以对比。

松辽盆地北部隐伏二叠系和侏罗系的初步研究

据50余口钻井揭露,松辽盆地北部隐伏的二叠系自下而上称杜尔伯特组(磨拉石)、一心组(残留海盆)、林甸组(火山弧)和四站组(大湖盆),是海西期阿尔泰型(增生弧型)造山带发育的记录,构造线为北东东向。侏罗系(主体为中侏罗统)大庆群由下部碎屑岩和上部蚀变火山岩组成,是古缝合线活化控制发育的燕山期陆内造山作用的磨拉石建造,构造线仍为北东东向,故侏罗系自内蒙东延入黑龙江省中-西部。晚侏罗世时松辽地区的磨拉石盆地闭合,中-酸性岩浆侵入活动仍十分活跃。据新的同位素年龄、化石和构造线方向等证据将火石岭组、沙河子组和营城组归为早白垩世早期,是北东向构造控制发育的松辽盆地断陷阶段的记录。文章列述了典型钻孔所见二叠系和侏罗系的岩石序列和地层分布,分析了其沉积—构造背景和演化,提出松辽盆地的基底是海西期增生弧型造山带,盆地早期的断陷伸展和火山作用是燕山造山带坍塌的地表反映。在此基础上讨论了早白垩世北东向新生构造在区域构造演化中的意义,探讨了前白垩系的油气远景。

铜仁坝黄震旦系老堡组顶部晶屑凝灰岩SHRIMP锆石U-Pb年龄及其地质意义

对于元古宙—显生宙的沉积—构造转换,前人做了大量研究工作,但一直以来未能获得较为一致的认识。野外调查发现,在处于上扬子东南缘台地与盆地相区的过渡带上的贵州铜仁坝黄长坪附近震旦系老堡组顶部硅质岩中,发育有一层10-20cm厚的凝灰岩夹层,岩石学研究也证实其为一层晶屑凝灰岩,并对其进行了SHRIMP锆石U-Pb年龄测定,获得556±5Ma沉积年龄。结合前人生物地层学、沉积学等研究成果,显示处于深水陆棚相区的老堡组顶部硅质岩与页岩互层段为扬子克拉通元古宙—显生宙之交沉积—构造转换过程中的一次重要的沉积事件,该沉积事件始于556Ma左右,可与扬子克拉通上的广泛的火山事件相对应,且可能与约550Ma时Rodinia超大陆最后裂解和Iapetus洋的形成有关。

江西省近年地质找煤规律小结

为了提高江西省主要能源矿产—煤炭资源的自给率,缓解能源瓶颈对江西省经济发展的制约,通过对近年来两级地质勘查基金项目和社会法人投资的找煤项目的研究,报告了江西省主要煤炭资源赋存情况、空间分布以及煤炭资源后备不足,研究开发已十分饱和的现状,并对矿山深部找煤、巨厚红层下找煤、滑覆构造下找煤等进行调查及预测,结合对新理论的研究探索,通过实施大量钻孔验证,探获了可观的煤炭资源。研究表明,江西省萍乐坳陷宜春至新余一带仍有找到大中型煤炭基地的前景,萍乡、赣南一些老矿山深部及周边仍可探求较丰富的煤炭资源量。

Geomorphological Evolution Revealed by Aeolian Sedimentary Structure in Badain Jaran Desert on Alxa Plateau, Northwest China

The Badain Jaran Desert,located in the Alxa Plateau,Northwest China,features mega-dunes and a unique dune-lake alternation landscape.This paper presented the aeolian sediment structures of three representative dunes in the Badain Jaran Desert using ground-penetrating radar (GPR).We processed and analyzed the GPR data and investigated the feasibility of using integrated GPR and sedimentological data to reconstruct dunes structure,sedimentary environment and geomorphological evolution.The results show that the internal structures of star dune and transverse dune represent various stages of mega-dune evolution: the main deposition processes of mega-dune are similar to those of transverse dunes but have a more complicated mechanism of sand transport and deposition because of the superimposition of dunes;the upper section of the mega-dune has a structure similar to that of star dune,with vertical aggradations on top.Diffraction hyperbolae in the GPR profile indicates that the presence of ancient dunes characterized by calcareous cementation layers is involved in the maintenance of mega-dunes,and water levels,shown by continuous,sub-horizontal GPR reflections,are supposed to be closely related to mega-dunes and the interdune lakes.Outcrop of wet sand and horizontal stratifications on the GPR image indicate moisture potentials with different levels inside mega-dunes.The multiplex geomorphology in the Badain Jaran Desert is the result of global climatic undulation,the unique geographical location,the geological structural features,etc.

Relation between structural evolution of the Longmenshan orogenic zone and sedimentation of its foreland basin

In order to determine the area for oil and gas exploration in China’s north Sichuan basin,we have divided the time during which the Longmenshan foreland basin was formed into five periods,based on the sedimentary response relationship of the foreland basin to structural evolution: 1) a late Triassic Noric period;2) an early-Middle Jurassic period;3) a late Jurassic to early Cretaceous period;4) a late Cretaceous to Paleogene-Neogene period and 5) the Quaternary period. As well,we analyzed the sedimentary environment and lithologic features of every basin-forming period. The results show that there are several favorable source-reservoir-cap assemblages in our study area,making it a major region for future oil and gas exploration in China’s northern Sichuan basin.

Architecture of volcanic sequence and its structural control of Yingcheng Formation in Songliao Basin

Yingcheng Formation is a set of volcanic strata composed of lava rocks,volcanic clastic rocks and sedimentary rocks,filled in some fault depressions in Songliao Basin,early Cretaceous.The study about litho-facies succession of Yingcheng Formation in the outcropped area of the southeast margin and in Xujiaweizi fault depression and its distribution based on analysis of seismic data,shows that the sequence of volcanic strata is quite different from the clastic sedimentary sequence.To study the architecture of volcanic sequence and its structural control of Yingcheng Formation in Songliao Basin,in this work,dividing of the volcanic sequence and dating of the sequence boundaries were finished firstly,then displacement and displacement rate of faults were calculated.The results show that,sample ages of top of the first member,the seconde member,and the third member are 127 Ma,115 Ma,110.7 Ma,respectively and sample age of the bottom of the third member is 114.7 Ma.The maximum displacement and displacement rate of the fault 1 are 3 km and 300 m/Ma,respectively,and those of the fault 2 are 3 km and 1000 m/Ma.Studies suggest that,the cooling unit of lava rock or pyroclastic rock is a basic genetic stratigraphic unit in volcanic sequence stratigraphy.Cooling units can construct a parasequence reflecting a volcanic eruption stage.A sequence was superimposed by some parasequences,responding to a volcanic active cycle.There are three types of volcanic sequences in Yingcheng Formation: type of explosion,type of effusion and type of mixed explosion-effusion.The surface of the volcanic sequence,an unconformity surface widely spread and traced in seismic profiles,is a base for analysis of volcanic sequence.The development of volcanic sequence was controlled by faulting,and the curves of fault displacement(rate)can reflect this control.The preservation of volcanic sequence was controlled by the type of volcanic structure and the regional subsidence,also different from that of the sedimentary.The type of volcanic structure of Xujiaweizi was a volcanic depression during the forming of Yingcheng Formation,and the breakdowns of volcanoes and structural subsidence were key factors in the volcanic sequences preservation.

Characteristics and evolution of lacustrine turbidite of Chang-7 Member of Yanchang Formation in northern Shaanxi

Lacustrine turbidite of Chang-7 Member in the studied area consists of sihstone and fine sandstone with respect to grain size, which is feldspathic lithie sandstone, syrosem arkose and arkose with respect to mineral constitution affected by provenance. There are such apparent signatures as lithology, sedimentary structure, sedimentary sequence and well logs, to recognize turbidite. During the paleogeographic evolution of Chang-7 Member, lake basin and deep lake are both at their maximum extent during Chang-73 stage, resulting in the deposition of Zhangjiatan shale with widespread extent and of turbidite with fragmental-like. Deep lake line is gradually moving toward lake center and turbidite sand bodies are gradually turning better with better lateral continuity, connectivity and more thickness, from stages of Chang-73, Chang-72 and Chang-7t, which can be favorable reservoir in deep-water.

THE THRUST AND NAPPE TECTONIC ZONE ALONG THE SOUTHERN MARGIN OF THE COAL-FORMING REGION OF NORTH CHINA

A thrust and nappe tectonic zone with imbricate branch thrusts is developed along the southern margin of the coal-forming region of North China. This tectonic zone is tightly related to the Qinling-Dabie collision orogen in genesis and belongs to the frontal zone of a huge thrust system developed during Yanshanian episode at the northern foot of the orogen. It is pointed out that thrusting had distorted the original depositional margin of the coal-forming region and some new coal-bearing blocks would be found out in the frontal sheets and under the undulate sole thrust.

Mineralization-related geochemical anomalies derived from stream sediment geochemical data using multifractal analysis in Pangxidong area of Qinzhou-Hangzhou tectonic joint belt, Guangdong Province, China

Distinguishing geochemical anomalies from background is a basic task in exploratory geochemistry. The derivation of geochemical anomalies from stream sediment geochemical data and the decomposition of these anomalies into their component patterns were described. A set of stream sediment geochemical data was obtained for 1 880 km 2 of the Pangxidong area, which is in the southern part of the recently recognized Qinzhou-Hangzhou joint tectonic belt. This belt crosses southern China and tends to the northwest (NE) direction. The total number of collected samples was 7 236, and the concentrations of Ag, Au, Cu, As, Pb and Zn were measured for each sample. The spatial combination distribution law of geochemical elements and principal component analysis (PCA) were used to construct combination models for the identification of combinations of geochemical anomalies. Spectrum-area (S-A) fractal modeling was used to strengthen weak anomalies and separate them from the background. Composite anomaly modeling was combined with fractal filtering techniques to process and analyze the geochemical data. The raster maps of Au, Ag, Cu, As, Pb and Zn were obtained by the multifractal inverse distance weighted (MIDW) method. PCA was used to combine the Au, Ag, Cu, As, Pb, and Zn concentration values. The S-A fractal method was used to decompose the first component pattern achieved by the PCA. The results show that combination anomalies from a combination of variables coincide with the known mineralization of the study area. Although the combination anomalies cannot reflect local anomalies closely enough, high-anomaly areas indicate good sites for further exploration for unknown deposits. On this basis, anomaly and background separation from combination anomalies using fractal filtering techniques can provide guidance for later work.

RESPONSE OF TRIASSIC SEQUENCE STRATIGRAPHY OF LOWER YANGTZE TO THE COLLISION BETWEEN THE YANGTZE PLATE AND THE NORTH CHINA PLATE

The characteristics of the Triassic sequences developed in the Lower Yangtze area display some great changes in both environment and climate. The change of environment was a transition from marine to continent via alternating environments. The change of climate was a transition from tropic （torrid） to warm and wet climate via subtropic dry climate. The type variations of the sequences were from the marine sequences to the continental sequences, corresponding to the changes of environments and climates. Sequence 1 is a type II of sequence of mixed elastic and carbonate sediments; sequence 2 is a type I of sequence of carbonate platform; sequence 3 is a type I of sequence of carbonate tidal flat-salt lagoon, sequence 4 is a type iI of sequence of lacustrine within marine layers, and sequence 5 is a sequence of lacustrine-swamp. The development, distribution and preservation of those sequences reveal the tectonic controls and their changes in the background. The collision between the Yangtze plate and the North China plate was a great geological event in the geological history, but the timing of the collision is still disputed. However, the characteristics of Triassic sequence stratigraphy and sea level changes in the Lower Yangtze area responded to this collision. The collision started at the beginning of middle Triassic and the great regression in the Lower Yangtze area started 22Ma earlier than those in the world. The tectonic conditions occurred before and during the collision controlled the development of sequences and type changes.

Interpretation of remote sensing of geological structures and prediction of gold mineralization in Mohe area and its adjacent region

The authors took the ETM+ multi-spectra data as the data information and correlation coefficient for each band and carried out their information volume statistics.According to certain criteria,the authors also determined the optimum band-combined image.The image clarity is improved by various enhancements and fusions method.Based on remote sensing geological interpretation in detail,the relationship between remote sensing geological characters and gold mine were analyzed systemically.Using all kinds of remote sensing structure information,combining other research data,the authors determined mainly ore-controlling ore structure.Several prospective areas of gold ores were determined and furthermore significant finding mine target areas was confirmed.

Coal forming environments and their relationship to tectonic activity in the Cévennes Stephanian coal basin

Coal forming environments in the tectonically controlled intermontane Stephanian Cévennes coal basin (Massif central, France) show a complex interelationship between structural and sedimentological features. The study of the general structural features and the geometry of the coal beds developed during the different stages in the evolution of the basin, and the spatial relation of the lithofacial units to the early tectonic activities, lead the authors to suggest the following model. The synsedimentary faults that occurred as both intrabasinal and marginal faults controlled not only the spatial distribution, shape and thickness of the detrital rock units and coal seams, but also caused the inversion of the tectonic style. The marginal faults exercised important controls on the geometry of the basin and the distribution of lithofacial units. However due to the subsidence of the central part of the basin and the depocenter, and the to differences in the timing and intensity of the displacement the coal enrichment zones shifted both vertically and laterally. This eventually resulted in the inversion of the whole tectonic framework from semi graben through graben to a new semi graben. The style and rate of the tectonic movement and basin filling that occurred in the Stephanian Cévennes coal basin were in turn closely linked with the tectonic movement in the surrounding area. Therefore the authors propose that the environment and processes of coal formation in this basin are closely linked to its tectonic evolution.

Geochemistry of sedimentary rocks from Permian–Triassic boundary sections of Tethys Himalaya: implications for paleo-weathering, provenance, and tectonic setting

The geochemical characteristics of two sections—the Permian–Triassic boundary(PTB) Guryul Ravine section, Kashmir Valley, Jammu and Kashmir,India; and the Attargoo section, Spiti Valley, Himachal Pradesh, India—have been studied in the context of provenance, paleo-weathering, and plate tectonic setting.These sections represent the siliciclastic sedimentary sequence from the Tethys Himalaya. The PTB siliciclastic sedimentary sequence in these regions primarily consists of sandstones and shales with variable thickness. Present studied sandstones and shales of both sections had chemical index of alteration values between 65 and 74; such values reveal low-to-moderate degree of chemical weathering. The chemical index of weathering in studied samples ranged from 71 to 94, suggesting a minor K-metasomatism effect on these samples. Plagioclase index of alteration in studied sections ranged from 68 to 92, indicating a moderate degree of weathering of plagioclase feldspars. The provenance discriminant function diagram suggests that the detritus involved in the formation of present studied siliciclastic sedimentary rocks fall in quartzose sedimentary and felsic igneous provenances. These sediments were deposited in a passive continental margin plate tectonic setting according to their location on a Si_2 O versus K_2O/Na_2 O tectonic setting diagram.

Erosion and Sediment Disasters in Cambodia1

This report first gives a general description of Cambodia and then discusses its topographic and geological features. Finally, the current situation concerning erosion and sediment disasters is discussed.

A Preliminary Analysis of Relations Between Tectonic Deformation of Sedimentary Cover and Basement in Kuqa Depression

Study of seismic activity in the Kuqa area enables us to infer some possible active faults in basement from the epicentral distribution on different profiles. The relations between active faults in the basement and surface structures are analyzed and the difference between sedimentary cover and basement in their deformation characteristics and the genesis are discussed. The following conclusions have been drawn: (1) the epicentral distribution indicates that, the east Qiulitag and south and north Qiulitag deep faults in the basement correspond to the east and west Qiulitag anticlines, respectively. Moreover, deep faults also exist beneath the Yiqiklik and Yaken anticlines. It indicates that the formation of surface structures is controlled by deep structures; (2) A NE-trending strike-slip fault develops along the line from the western termination of Yiqiklik structure to Dongqiu Well 5 and a NW-trending active fault on the western side of Baicheng. The two active faults across the tectonic strike are the main causes for tectonic segmentation of the Kuqa depression and possibly the cause for the middle segment (Kuqa-Baicheng) of the depression to be more shortened than both its eastern and western terminations; (3) The difference between the sedimentary cover and basement in their deformation characteristics depends mainly on the different properties of media between them. The lithospheric strength of the basement in the basin is fairly high, which determines the basement deformation to be mainly of brittle fracture——seismic activity. While the strength of sedimentary cover is low, where there exist weak thin layers, such as coal and gyps. Under the effect of strong tectonic compression, the sedimentary rocks may undergo strong viscous or plastic flow deformation; meanwhile, an aseismic detachment may take place along the weak layers.

New tectonic map of Northern-Central-Eastern Asia： Position and evolution of Mesozoic sedimentary basins

The beginning of the XXI century was marked a new rising of the international tectonic cartography as a result of analysis and synthesis of a huge volume of geological information obtained for the territory of Asia es-pecially during the last 30 years. The previous tectonic maps for Asia were created in the 1960s-1970s of the last century. Since that time, the national geological surveys have compiled tectonic maps exclusively in the limits of their own state boundaries. The international cooperation of five countries since 2002 （ Russia, China, Mongolia, Kazakhstan and Republic of Korea） gave a unique possibility to join the data into a united cartog-raphic form as Atlas of Geological Maps （since 2002-Atlas of Geological Maps of Central Asia and since 2007- Atlas of Geological Maps of Northem-Central-Eastem Asia）. Both atlases include four maps： geological, tecton-ic ,metallogenic, and energy resources. Tectonic Map of Northem-Central-Eastem Asia and Adjacent Areas at scale 1 ： 2 500 000 was the key map for further compilation of the metallogenic and energy resources （ coal, oil and gas） maps. By this reason, special attention was given to showing the structure and composition of the Mes-ozoic sedimentary basins in Northern-Central- Eastern Asia as the most perspective structures for oil-and-gas and coal prospect.