Mesozoic basin development and its indication of collisional orogeny in the Dabie orogen

来源 :Chinese Science Bulletin | 被引量 : 0次 | 上传用户:sese4546
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The Dabie orogen underwent deep continental subduction, rapid exhumation, and the huge amount of erosion during the Mesozoic. Its tectonic evolution, especially how its evolution was recorded by sedimentary basins at the flanks of the Dabie orogen is one of the most important issues of the world’s attention. These years, newly studies of basin sedimentology, combined with structural geology, have shown a fundamental progress. The overall distribution of different basin types in the orogen indicates that shortening and thrusting at the margins of the orogen from the Late Triassic to the Early Cretaceous controlled the foreland basins, and extension, doming and rifting were initiated in the core of the orogen from the Jurassic to the Early Cretaceous and were expanded to the whole orogen after the Late Cretaceous. Therefore, The Dabie orogen records gradual transition from overall shortening and thrusting to dominantly extension and rift basin formation expanded from its core to its margins, although these shortening and extension overlapped in time from the Jurassic through Early Cretaceous at crustal levels. The unroofing ages of the ultra-high pressure (UHP) metamorphic rocks in the Dabie orogen change from Early Jurassic to Late Jurassic westward. The depth of exhumation increases eastwards. The sediment sources for the Hefei basin are mostly composed of the deeply exhumed, axial Dabie metamorphic complex, and the sediment sources for the Middle Yangtze basin are mostly from cover strata in the southern orogen and related strata with subjacent (i.e. subsequently overthrusted) Mianlue suture belt. Geodynamic analysis represents that continental collision between the North China Block and the South China Block along the Shangdan and Mianlue sutures, subsequently northwestward progradation of the Jiangnan fold and thrust belt, and the underthrusting of the North China Block along the Northern Boundary Fault of Qinling Range led to crustal thickening, gravitational spreading and balanced rebound of the resultant thick crustal welt, and multi-episodic exhumation of the HP/UHP metamorphic rocks. The future studies by the methods of tracing the Dabie orogeny through deposition in the marginal basins should focus on eastward extension of the Mianlue suture, thrust and overlap of the Dabie HP/UHP metamorphic block on different lithotectonic zones and basins along the northern South China Block, the structural framework of the source area of the basins in the syn-depositional stage, the basin lateral extension, huge amount of erosion and sediment transportation from the Dabie blanket and basement rocks, and recovery of subducted and re- moved structural units within the Dabie orogen, etc. The Dabie orogen underwent deep continental subduction, rapid exhumation, and the huge amount of erosion during the Mesozoic. Its tectonic evolution, especially how its evolution was recorded by sedimentary basins at the flanks of the Dabie orogen is one of the most important issues of the the full distribution of different basin types in the orogen that shortening and thrusting at the margins of the orogen from the Late Triassic to the Early Cretaceous controlled the foreland basins, and extension, doming and rifting were initiated in the core of the orogen from the Jurassic to the Early Cretaceous and were expanded to the whole orogen after the Late Cretaceous. Thus, The Dabie orogen records gradual transition from overall shortening and thrusting to dominantly extension and rift basin formation expanded from its core to its marg ins, although these shortening and extension overlap in time from the Jurassic through Early Cretaceous at crustal levels. The unroofing ages of the ultra-high pressure (UHP) metamorphic rocks in the Dabie orogen change from Early Jurassic to Late Jurassic westward. The depth of exhumation increases eastwards. The sediment sources for the Hefei basin are mostly composed of the deeply exhumed, axial Dabie metamorphic complex, and the sediment sources for the Middle Yangtze basin are mostly from cover strata in the southern orogen and related strata with subjacent (ie, overthrusted) Mianlue suture belt. Geodynamic analysis represented that continental collision between the North China Block and the South China Block along the Shangdan and Mianlue sutures, subsequently northwestward progradation of the Jiangnan fold and thrust belt, and the underthrusting of the North China Block along the Northern Boundary Fault of Qinling Range led to crustal thickening, gravitational spreading and balanced rebound of the resultant thick crustal welt, and multi-episodic exhumation of the HP / UHP metamorphic rocks. The future studies by the methods of tracing the Dabie orogeny through deposition in the marginal basins should focus on eastward extension of the Mianlue suture , thrust and overlap of the Dabie HP / UHP metamorphic block on different lithotectonic zones and basins along the northern South China Block, the structural framework of the source area of ​​the basins in the syn-depositional stage, the basin lateral extension, huge amount of erosion and sediment transportation from the Dabie blanket and basement rocks, and recovery of subducted and re- moved structural units within the Dabie orogen, etc.
其他文献
生活质量作为全面体现患者各种行为能力的测定指标,涵盖了人体机能、心理和精神状态以及社会活动等多方面内容,近年来逐渐成为评价疾病治疗临床效果的常用指标.本文就与白内障视觉相关的生活质量测定方法和量表、白内障摘除手术后生活质量的结果及其影响因素、生活质量测定结果与其他视觉检查结果间的关系以及测定生活质量时应注意的问题等进行阐述。
由机械电子工业部第29研究所编写的《电子结构设计标准手册》审稿会于6月1日至4日在成都召开。来自各部属的厂、所36名结构设计专家和代表出席了审稿会。本《手册》被中国标
享受阳光体验尊贵2007温州之星高尔夫邀请赛开杆6月2日,由温州之星奔驰举办的2007梅赛德斯-奔驰高尔夫邀请赛,梅赛德斯-奔驰杯温州地区的预选赛在温州仰义高尔夫球场正式开杆
主要研究乘客安全气囊模块中支架的随机振动强度分析有限元仿真,并根据仿真结果,进行关键部位的结构改进。首先利用Catia建立支架的三维模型,利用Hypermesh进行有限单元网格
期刊
期刊
采用MBE工艺,研究在AlGaAs中δ掺硅,并生长了单δ层和多δ层两种结构。用电化学C-V和SIMS测量离化硅浓度和硅原子浓度分布。SIMS测量结果表明升高硅源温度比延长硅注入时间对
原发性十二指肠肿瘤(primary tumors of the duodenum,PTD)是指原发于十二指肠各段的肿瘤,其发病率虽低,但近年来呈明显上升趋势[1-4],PTD按其病变性质可分为良性和恶性。原
广东作为全国受到国际金融危机冲击最早、遇到的挑战最大、受影响最重的省份,坚决贯彻落实中央的各项决策部署,以科学发展观为指导,迎难而上、化危为机,经济发展呈现出明显
想躺就躺,想坐就坐。任你想做出什么姿势,它一定能满足你。这就是“飞鱼”--一款可以让你随心所欲坐的椅子。设计师将板条安装在一个可旋转的圆筒上,使用者可以随意旋转板条位置