Jurassic depositional records and sandstone provenances in Hefei Basin, central China: Implication for Dabie orogenesis   总被引：3，自引：0，他引：3  

Zhong Li  Renwei Li  Shu Sun  Qingchen Wang 《Island Arc》2004,13(2):346-358

Abstract   Detrital composition and major element geochemistry of Jurassic sandstones in the south Hefei Basin, central China, show their provenance to be the Dabie Mountains, whose tectonic attributes are closely related to continent–island arc complexes. It was found that a provenance change, from recycled orogen signatures and mixed orogenic sandstones to arc orogen, occurs from the lower Middle Jurassic to the Upper Jurassic (the Zhougongshan Formation). Dissected magmatic arc sources were gradually exposed in the Dabie Mountains due to intensive exhumation during the Late Jurassic, particularly after the Fenghuangtai depositional phase. Furthermore, it can be infered that the magmatic arc was initially present in both the Early Paleozoic and the Triassic, according to isotopic dating studies in previously published reports. δ¹³C–δ¹⁸O tracing between existing marbles of different strata in the Dabie block and marble gravels of the Fenghuangtai Formation in the Hefei Basin indicate that partial lithostratigraphic units for the Jurassic provenances have entirely disappeared from the Dabie block; therefore, it is impossible to reconstruct integral orogenic processes from studies on the remaining Dabie block alone. These findings, together with basin-fill sequences, also suggest that the Hefei Basin was mainly subjected to compressive mechanical regimes rather than extensional regimes in the Jurassic, which resulted in reverse-grading clastic depositional sequences, and is probably related to the northward intracontinental deep subduction of the Yangtze Plate. Regional exhumation properties and a tectonic model of the Late Mesozoic Dabie orogenesis are discussed in this paper.  相似文献   

华北克拉通东部南北缘中生代火山沉积格局及其构造转折过程   总被引：3，自引：0，他引：3  

李忠  董仁国  郑建平 《古地理学报》2007,9(3):227-242

通过华北克拉通东部北缘和南缘盆地充填序列和盆地分布演化对比研究，解析了该区中生代构造转折过程。研究发现两侧盆地均大致从早侏罗世开始发育，约以晚侏罗世为界，之前盆地充填记录反映以挤压作用、岩石圈增厚为主，之后以陆内伸展、岩石圈减薄为主，显示晚侏罗世明显的构造转折，并且地壳浅部的构造体制转变均滞后于岩石圈深部构造环境的变化。然而，两侧盆地演化也有明显差别：①北缘燕辽地区从早侏罗世到白垩纪，发育了多层系的从基性、中基性到中酸性的火山岩及火山碎屑岩组合，而南缘合肥盆地仅在晚侏罗世早白垩世产出钙碱性火山岩及火山碎屑岩组合，反映出不同的深部构造过程和源区特征；②北缘的岩石圈减薄可能始于约163 Ma，南缘明显的岩石圈减薄则始于约149 Ma，而反映在盆地构造与充填尺度上的伸展作用分别对应于大约145 Ma和132 Ma；③晚侏罗世构造转折期，北缘燕辽地区粗碎屑沉积以河流体系为主，反映盆山地势高差较小；而南缘该期发育冲积扇体系，盆山地势高差较大；④北缘盆地沉积中心迁移规律复杂，而南缘总体呈现由南向北的迁移趋势。显然，大别山碰撞造山和后造山期强烈的隆升和剥露对南缘盆地演化具有极大的主导和制约作用，而北缘则显示出强烈的壳幔相互作用并伴有区域性的陆内挤压推覆（转折前）和张裂 伸展（转折后）交替的特点。华北克拉通晚中生代构造转折的时限北缘较南缘早，说明诱发这一转折事件的区域构造动力可能首先与华北北部壳幔相互作用密切关联。  相似文献   

合肥盆地断层活动特征及其控制因素   总被引：2，自引：2，他引：2  

许世红  钟建华  柳忠泉 《大地构造与成矿学》2007,31(1):31-36

利用断层活动速率法定量分析了合肥盆地主要近东西向断层的活动规律,并分析了它们形成与演化的控制因素。研究表明,盆地前侏罗系基底主要发育了近东西向、南倾的逆冲断层,属于印支期前陆变形的产物。这些断层的逆冲速率向南有规律的增加,指示其动力来自南部大别造山带的碰撞造山。盆地在侏罗纪期间接受大量沉积时,并没有发生明显的断裂活动,指示属于前陆拗陷型盆地,其对应着大别造山带的快速隆升。盆地在早白垩世至古近纪期间演变为断陷盆地,印支期基底的逆断层转变为正断层活动。这些盆地内主要的近东西向正断层的伸展活动在早白垩世呈现北强南弱,而随后转变为南强北弱的变化趋势。  相似文献   

合肥盆地东部中-新生代的演化及其对郯庐断裂带活动的响应   总被引：12，自引：4，他引：12       下载免费PDF全文

刘国生  朱光  牛漫兰  宋传中  王道轩 《地质科学》2006,41(2):256-269

合肥盆地的沉积作用与其东缘的郯庐断裂带演化有着良好的耦合关系。侏罗纪盆地发育主要受大别造山带演化控制,东部可见对同造山期郯庐断裂带左旋转换走滑的沉积响应。盆地内朱巷组的沉积是对早白垩世早期郯庐断裂再次发生陆内左行平移的响应,该时期成盆模式为一走滑—挠曲盆地。盆地内上白垩统—古近系的形成是对这期间郯庐断裂带伸展活动的响应,盆地具区域性伸展(双向伸展)的特征。盆地东部自新近纪以来的抬升、消亡与东缘反转构造的存在,指示了郯庐断裂带的逆冲活动。盆地东部的沉积记录结合近年来郯庐断裂带内部构造与同位素年代学的最新研究成果,指示该断裂带中-新生代经历了4个演化阶段:同造山期的左旋转换走滑、早白垩世早期的陆内左行平移、晚白垩世—古近纪的伸展运动和新近纪以来的逆冲活动。  相似文献   

早白垩世合肥盆地性质及含油气性分析   总被引：4，自引：1，他引：4  

易万霞  赵宗举  李学田  沈金龙  周进高 《大地构造与成矿学》2003,27(1):64-71

根据地震、电法、盆地模拟等新资料并结合区域地质资料的综合分析,对早白垩世合肥盆地的复杂构造及盆地性质、演化进行了深入讨论,认为合肥盆地在早白垩世时属于一个处于由压性应力场向张性应力场转换过程中形成的复杂复合盆地,即早白垩世早中期属主要受控于其南侧大别造山带的滑覆冲断类前陆盆地、早白垩世中晚期属主要受控于其东侧郯庐断裂活动的走滑拉分盆地。进而探讨了其拉分盆地内潜在的下白垩统油气系统及其勘探前景。从盆地研究的角度来进一步认识郯庐断裂的活动及对合肥盆地的油气勘探均具有借鉴及指导意义。  相似文献   

Thrusting and Exhumation Processes of a Bounding Mountain Belt: Constraints from Sediment Provenance Analysis of the Hefei Basin   总被引：3，自引：0，他引：3  

LIU Shaofeng  LIU Wencan  Faculty of Geosciences  Resources  China University of Geosciences  Beijing DAI Shaowu  Institute of Exploration  Development  Jianghan Petroleum Administration  Guanghu  Hubei ProvinceHUANG Siji China University of Geosciences  Wuhan  LU Wuyun Anhui Bureau of Geology  Mineral Resources  Hefei 《《地质学报》英文版》2001,75(2):144-150

Lithic (or gravel) composition analyses of the Jurassic Sanjianpu Formation and Fenghuangtai Formation in the Hefei basin show that the sediment provenance consists mainly of four kinds of rock units: the basement metamorphic complex, granitic rocks, medium- and low-grade metamorphic rocks, and sandy and muddy sedimentary rocks, which are distributed along the bounding thrust belt. The whole stratigrapnic section can be divided into 2 lithic sequences and 7 subsequences. The regular distribution and changes of lithic fragments and gravels in lithic (or gravel) sequences reflect that the bounding thrust belt of basin has undergone 2 thrusting cycles and 7 thrusting events. Lithic (or gravel) composition analyses of the basin fully reveal that the northern Dabie basement metamorphic complex was exhumed on the earth's surface in the Middle and Late Jurassic, and extensive intermediate and acid intrusive rocks were developed in the southern North Huaiyang or northern Dabie Mountains during the basin's synde  相似文献   

合肥盆地东北缘白垩纪地层特征及沉积环境分析   总被引：10，自引：0，他引：10  

吴跃东  侯明金  刘家云 《安徽地质》1999,(2)

合肥盆地东北缘白垩纪地层广泛发育、地层较完整,自下而上为：新庄组、邱庄组和张桥组等3个岩石地层单位。白垩纪在合肥盆地均为陆相沉积,沉积相的纵、横向变化均较大,有洪积扇、冲积扇、河流、风成、浅湖和深湖相。合肥盆地东北缘的形成和演化受郯庐断裂所控制,早白垩世早期,郯庐断裂左行平移,产生北东向拉分,形成断、坳陷盆地,至早白垩世晚期,郯庐断裂北西—南东向伸展,形成地堑式断陷盆地。  相似文献   

合肥盆地中生界地层的热演化程度——伊利石结晶度的指示   总被引：6，自引：0，他引：6  

朱莉  朱敏 《安徽地质》2006,16(3):169-172,176

合肥盆地中生界地层的热演化程度以往了解的十分有限。通过盆地内中生界地层一系列自生伊利石结晶度值的测试,揭示地表白垩系地层多数处于成岩作用的晚期,少部分处于成岩作用中期,分别指示其中有机质进入了中—高成熟期或成熟期。钻井中1000m以上地层也处于成岩作用的中期或晚期,类似于地表样品。而钻井中1000m以下所有中生界地层都进入了埋藏变质阶段,指示着有机质的过成熟期。其中1000～3000m深的热演化温度为200～250℃。而3000m以下的热演化温度基本上为250～300℃。这些测试结果为合肥盆地今后的油气远景评价与勘探提供了重要的信息。  相似文献   

Mesozoic “Red Beds” and its Evolution in the Hefei Basin     

ZHANG Jiaodong  CHEN Xuanhu  LI Qiuli  LIU Chengzhai  LI Bing  LI Jie  LIU Gang  REN Fenglou 《《地质学报》英文版》2012,86(5):1060-1076

The Hefei Basin is the largest basin in the North China landmass with complete and well-preserved Mesozoic and Cenozoic strata. In the basin there developed a suite of extremely thick “red beds” in the Mesozoic. Owing to complex evolution processes and a lack of paleontological traces, there have been controversies regarding the division and correlation of this suite of red beds. Based on results obtained in recent years in drilling, seismic and surface geological investigations and in consideration of relationships between seismic sequences and regional tectonic events, as well as evidence in paleontology, petrology and isotopic dating, this paper preliminarily puts forward the following ideas about the sequence stratigraphic framework of the continental “red beds” in the Hefei Basin. (1) The Zhougongshan Formation and the Yuantongshan Formation have similar lithologic, geophysical and paleontological characteristics, so we incorporate them into a single formation, called the Yuantongshan Formation, and the original Zhougongshan and Yuantongshan Formations are regarded as the upper and the lower parts of the newly defined Yuantongshan Formation. Its age is the Middle Jurassic; (2) the Zhuxiang Formation belongs to the Upper Jurassic Series and (3) the age of the Xiangdaopu Formation is the Lower Cretaceous. Furthermore, signatures of depositional evolution are analyzed in the paper based on features of seismic reflection, outcrops and drilling data. The Early and Middle Jurassic is characterized by a foreland basin, which is influenced mainly by uplift and longitudinal compression of the Dabieshan Mountains; the Lower Jurassic System has a relatively small depositional area; the Middle Jurassic strata are distributed extensively over the whole basin, marking the summit of basin development; a flexure basin is characteristic of the Late Jurassic, manifesting a joint effect of the Dabieshan and Zhangbaling Mountains with the former being more significant. In the Early Cretaceous, the Xiangdaopu Formation was distributed in the Daqiao depression, evidently affected by extension of the Tanlu fault; in the Late Cretaceous, the Hefei Basin was subjected to dismembering and the Zhangqiao Formation was distributed in the east-west direction along the downthrown side of the fault.  相似文献   

运用时序InSAR技术监测合肥市地面沉降及断裂活动     

于书媛  杨源源  张鹏飞  孙军  骆佳骥 《大地测量与地球动力学》2021,41(4):398-402

基于覆盖合肥地区的24景Sentinel-1A数据,采用PS-InSAR和SBAS-InSAR时序处理方法获取2017-11~2019-10合肥市城区及周边地面形变分布信息,分析主城区地面沉降的时空演化规律,获取地铁网络沿线地表形变空间分布图。结果表明,合肥市地铁线路沿线发生不同程度形变,形变严重区域主要集中在西部及西南部,最大沉降速率达到35 mm/a。对池河-西山驿断裂形变场进行宏观分析,并结合时空同步的跨断层水准数据进行对比验证,认为2种数据的垂直形变监测结果具有一致性,推测数据的垂直升降变化可能受断层拉张和挤压交替控制。  相似文献