Middle–Late Triassic sedimentation in the Helanshan tectonic belt: Constrain on the tectono-sedimentary evolution of the Ordos Basin,North China     

Jiaopeng Sun  Yunpeng Dong 《地学前缘(英文版)》2019,10(1):213-227

The Helanshan tectonic belt is located to the west of the Ordos Basin, and separates the Alxa (or Yinshan) Massif to the west from the Ordos block to the east. Triassic sedimentation in the Helanshan tectonic belt records important information about tectono-sedimentary process between the Alxa Massif and the Ordos block. Detailed geological mapping and investigation on the lithological package, sedimentary facies and paleocurrent orientation have been conducted on the Middle to Upper Triassic clastic rocks in the Helanshan tectonic belt. The succession is characterized by upward-fining sequence and comprises coarse grained alluvial-fluvial facies in the lower part as well as deltaic-lacustrine facies in the upper part. Based on detailed study and comparisons on the sedimentary sequence along various sections, the Middle to Upper Triassic strata have been revealed that show clear southeastward-deepening sedimentary differentiation and transgression from southwest to northeast, which are consistent with the southeastward flowing paleocurrent. These features indicate a southeastward-dipping paleogeography in the Helanshan tectonic belt, which was original western part of southeastward orientated fluvial-lacustrine system in the northwestern proto-Ordos Basin. Further to the east, the Triassic succession in the Ordos Basin displays gradually thickening and alluvial-fluvial system flowed from southeast to northwest, showing a huge thick sedimentary wedge in the western basin margin. Together with the Late Permian–Early Triassic closure of the Paleo-Asian Ocean to the north, the Late Triassic extensional structures and diabase dykes in the Helanshan tectonic belt, all the above sedimentary features could be mostly interpreted as records of an extensional basin correlated to post-collisional collapse of the Central Asian Orogenic Belt.  相似文献   

Petroleum System of the Sufyan Depression at the Eastern Margin of a Huge Strike-slip Fault Zone in Central Africa   总被引：2，自引：1，他引：1  

ZHANG Yamin  and GU Qin 《《地质学报》英文版》2009,83(6):1182-1187

Abstract: The present paper mainly studies the petroleum system of the Sufyan Depression in the Muglad Basin of central Africa and analyzes its control of hydrocarbon accumulation. On the basis of comprehensive analysis of effective source rock, reservoir bed types and source–reservoir–seal assemblages, petroleum system theory has been used to classify the petroleum system of the Sufyan Depression. Vertically, the Sufyan Depression consists of two subsystems. One is an Abu Gabra subsystem as a self generating, accumulating and sealing assemblage. The other subsystem is composed of an Abu Gabra source rock, Bentiu channel sandstone reservoir and Darfur group shale seal, which is a prolific assemblage in this area. Laterally, the Sufyan Depression is divided into eastern and western parts with separate hydrocarbon generation centers more than 10?000 m deep. The potential of the petroleum system is tremendous. Recently, there has been a great breakthrough in exploration. The Sufyan C-1 well drilled in the central structural belt obtained high-yielding oil flow exceeding 100 tons per day and controlled geologic reserves of tens of millions of tons. The total resource potential of the Sufyan Depression is considerable. The central structural belt is most favorable as an exploration and development prospect.  相似文献   

青藏高原中部温泉盆地西缘的晚新生代正断层作用   总被引：10，自引：1，他引：9       下载免费PDF全文

吴中海  叶培盛  刘琦胜  吴珍汉  胡道功  赵希涛  周春景 《地震地质》2004,26(4):658-675

在青藏高原中部的温泉盆地西侧发育了1条倾向东的强烈活动的近SN正断层——温泉盆地西缘断裂。它是在印度板块与欧亚板块强烈碰撞的背景下,青藏高原中北部地区自晚新生代以来发生近EW向伸展变形的产物。晚新生代以来,该断裂上的最大垂直错动量不会<21km,错动中生代褶皱地层所暗示的最大垂直位移量为(60±22)km。第四纪期间,该断裂发生了多期活动,形成了山前的多套断层三角面和多级断层陡坎地貌。根据断裂垂直错动晚第四纪期间不同时代的地层和地貌体所形成的断层崖高度估算,其晚第四纪以来的最大活动速率不超过12mm/a,平均活动速率为045mm/a。初步的探槽分析表明,晚更新世末期以来沿该断裂至少发生了3次震级不同的古地震事件。综合该断裂的全新世活动特点推断,它是在未来具有较大可能发生6～7级地震的一条重要控震断裂  相似文献   

Mantle anisotropy across the southwestern boundary of the Ordos block,North China          下载免费PDF全文

Yongcai Tang  Yongshun John Chen  Yuanyuan V. Fu  Haiyang Wang  Shiyong Zhou  Eric Sandvol  Jieyuan Ning  Yongge Feng  Mian Liu 《地震科学（英文版）》2010,23(6):549-553

Located at the northeastern margin of the Tibetan plateau,the Ordos block is a stable tectonic unit in North China.With its active boundary fault zones,the Ordos block played an important role in the eastward extrusion mechanism of the Tibetan plateau.Peking University deployed a linear array of 15 portable broadband seismometers across the western Weihe graben during September 2005 to August 2006 and later a 2-D seismic array(Southwest Ordos Array) of 14 portable broadband seismometers during 2007-2008 at its southwestern boundary.Analyses of shear wave splitting of SKS and SKKS phases at these stations show that the fast directions trend ～110° with an average delay time of 0.9 s in the southwestern margin of the Ordos block.The agreement between the lithosphere deformation indicated by GPS data and Quaternary fault slip-rate observations and the mantle flow represented by shear wave splitting implies that accordant deformation patterns from lithosphere to asthenosphere in relation to the eastward extrusion of the Tibetan plateau could extend at least to 200 km depth.Spatial distribution of splitting polarization directions indicates that the mantle flow driven by the Tibetan plateau is blocked by the Ordos block and locally restricted in a narrow channel along the Qinling-Dabie fault zones between the Ordos block and Sichuan basin.  相似文献   

罗布泊荒漠地区湖泊蒸发盐资源的形成及环境演化   总被引：9，自引：0，他引：9  

胡东生  张华京 《冰川冻土》2004,26(2):212-218

通过地球卫星遥感资料和地面调查以及化学测试等综合研究, 证实罗布泊地区存在大型现代液体钾盐矿床. 用钻探材料及系统分析方法重建了20 ka BP以来湖泊沉积序列和环境物性柱剖面, 用天然水体五元体系稳定相图讨论了古湖泊湖水及现代湖水的饱和流结晶路线及成盐成矿演化趋势. 结果证明, 液体钾盐矿床的分布及成钾成矿环境受现代地壳运动作用下新生地堑构造系统的控制.  相似文献   

伊通盆地二号断层与西拉木伦河断裂带及油气的关系   总被引：2，自引：0，他引：2  

江涛  邱玉超  王立武  宋立忠  苗洪波  丁冶 《吉林大学学报(地球科学版)》2008,38(3):411-416

利用重力、航磁、电法和地震资料,结合区域构造地质特征,对伊通盆地二号断层研究认为:二号断层是西拉木伦河断裂带向吉林省东部延伸的一部分。佳木斯-伊通地堑的左旋活动将西拉木伦河断裂带错断,在地堑内保留的西拉木伦河断裂带的一部分作为伊通盆地的基底断层。该断层继承性活动,断层两侧地层发生差异性沉降,逐渐演化为现今的二号断层。作为伊通盆地内一条最重要的同沉积断层,二号断层控制其上下盘地层的沉积和油气成藏。二号断层与其上盘构成陡坡断裂坡折带,控制上盘的沉积物分布;同时断穿基底,沟通下部双阳组和奢岭组的油气源。二号断层早期开启有利于运移油气,晚期盆地反转时封闭,对梁家构造带的油气藏保存起积极作用。  相似文献   

Depositional Sequences of Yitong Graben (Eastern China) and Its Response to Transform-Extensional Processes   总被引：1，自引：0，他引：1  

Lu Yongchao  Ren Jianye  Li Sitian  Chen Ping  Ye Hongpo  Cui Xuezhou  Li Bencai 《中国地质大学学报(英文版)》1999,10(2):170-177

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＴａｎｃｈｅｎｇ－Ｌｕｊｉａｎｇｆａｕｌｔｂｅｌｔｉｓｔｈｅｌａｒｇｅｓｔｓｔｒｉｋｅ－ｓｌｉｐｆａｕｌｔｂｅｌｔｉｎＥａｓｔＣｈｉｎａ．Ｔｈｉｓｆａｕｌｔｂｅｌｔｈａｓｕｎｄｅｒｇｏｎｅａｃｏｍ－ｐｌｉｃａｔｅｄｇｅｏ...  相似文献   

Geomorphic assessment of active tectonics in the Acambay graben,Mexican Volcanic Belt     

María Teresa Ramírez-Herrera 《地球表面变化过程与地形》1998,23(4):317-332

Spatial variations of Quaternary deformation and tectonic activity of faults along the Acambay graben are assessed using geomorphic and morphometric approaches. The Acambay graben is an east–west trending structure of apparent Quaternary age, located in the central part of the Mexican Volcanic Belt, which gives rise to pronounced scarps over a distance of about 80 km. Continuing tectonic activity in the Acambay graben is confirmed by recent well documented seismic episodes. The intensity of active tectonics has been interpreted through a detailed geomorphic study of the fault-generated mountain fronts and fluvial systems. The combined geomorphic and morphometric data provide evidence for relative variations in tectonic activity among the Acambay graben faults. Geomorphic indices suggest a relatively high degree of tectonic activity along the Venta de Bravo and the Acambay–Tixmadeje faults, followed, in order of decreasing activity, by the Pastores, Temascalcingo and Tepuxtepec faults. Spatial variations within faults have also been identified, suggesting a higher level of tectonic activity at the tips of the faults. This pattern of variation in the relative degree of tectonic activity is consistent with field evidence and seismic data for the Acambay graben. Geomorphic evaluation of the Acambay graben faults suggests that the Acambay–Tixmadeje and Venta de Bravo faults, and specifically the tips of these faults and a central segment near the town of Venta de Bravo, should be considered as areas of potentially high earthquake risk. © 1998 John Wiley & Sons, Ltd.  相似文献   

库车坳陷东部晚白垩世古隆起及构造应力场恢复     

王珂  曹婷  魏红兴  肖安成  周露 《地质学报》2020,94(6):1716-1726

库车坳陷东部具有丰富的油气资源,其构造变形机制与南天山造山带密切相关。综合采用露头共轭节理及白垩系残余厚度分布,分析了库车坳陷东部晚白垩世古隆起特征及构造应力场属性。吐格尔明、克孜勒努尔沟、库车河、卡普沙良河、吉迪克以及库车河西6条剖面的共轭节理分析表明,库车坳陷东部新生代构造挤压应力为NNW-SSE向,而中生代的构造挤压应力为NE-SW向。原型盆地恢复显示,库车坳陷白垩纪的沉积中心大致位于大北1井―吐北2井―克拉2井一线,且发育秋里塔格―新和―牙哈―提尔根古隆起带,白垩系原始沉积厚度总体上北厚南薄。在晚白垩世区域抬升剥蚀的构造背景下,坳陷东部受压隆升遭受剥蚀,白垩系残余厚度减薄,呈西厚东薄的趋势。位于坳陷东部的吐格尔明背斜在石炭纪―三叠纪为一个长期存在的继承性沉积古隆起,晚白垩世进一步隆升形成构造古隆起,背斜周缘的白垩系残余厚度进一步减薄。吐格尔明背斜和背斜周缘白垩系残余厚度等值线以及库北1井和库车河剖面周缘白垩系残余厚度等值线的长轴方向均为NW-SE向,进一步证实了库车坳陷东部晚白垩世的构造应力为NE-SW向。库车坳陷东部晚白垩世古隆起与构造应力场属性主要与特提斯造山带中地体增生和拼贴作用导致的特提斯北缘盆地群中发生的区域性抬升有关。  相似文献   

依舒地堑汤原、方正断陷古近纪边界断裂活动特征   总被引：7，自引：4，他引：3  

王孔伟  张帆  刘志宏  张兴洲 《大地构造与成矿学》2006,30(4):445-454

依舒地堑位于黑龙江省东部,为一新生代断陷盆地,汤原断陷和方正断陷为其两个面积较大的二级构造单元。通过对汤原断陷和方正断陷边界断裂的研究,可以进一步了解依舒断裂带的形成和演化过程。研究发现,在始新世-渐新世依舒地堑边界断裂的活动整体上具有多中心、不均衡的特征,汤原断陷东部的边界断裂为控盆断裂,方正断陷东、西两侧的边界断裂对盆地的发展都具有一定的控制作用,但西部边界断裂为主要控盆断裂。断层的生长指数分析表明,依舒地堑内部的北西向断裂与边界断裂的活动具有一致的规律性,都起到协调边界断裂演化发展的作用。依舒地堑边界断裂转换引张方向是由莫霍面梯度带的倾斜方向所决定,梯度带的倾向与地堑的整体伸展方向相同。  相似文献