扬子北缘晚造山阶段弧形构造特征与盆地演化  

Late-orogenic arcuate fold-thrust belts in northern Yangtze area:Structural characteristics and basin evolution

作　　者：王平[1,2] 刘少峰[3] 郑洪波[1] 王凯[4] 郜瑭珺[5] 潘峰[4] 李王鹏 姜承鑫[3,6] 陈宇亮 杨雪松[7] 

机构地区：[1]南京师范大学地理科学学院,江苏南京210046 [2]南京大学地球科学与工程学院,江苏南京210093 [3]中国地质大学(北京)地质过程与矿产资源国家重点实验室,北京100083 [4]西安地质矿产研究所,陕西西安710054 [5]中国石化勘探南方分公司,四川成都610041 [6]Department of Earth and Planetary Sciences,Macquarie University [7]中国石油华北油田分公司第三采油厂,河北河间062450

出　　处：《古地理学报》2013年第6期819-838,共20页Journal of Palaeogeography：Chinese Edition

基　　金：国家自然科学基金项目(编号:41102104;41030318;40830107);中国石油化工股份有限公司"南方海相前瞻性项目"共同资助

摘　　要：扬子北缘晚造山阶段(即晚侏罗世—晚白垩世)发育以弧形构造为特征的前陆薄皮逆冲—褶皱构造,包括了沿秦岭—大别造山带发育的北西向的大洪山和大巴山弧形带,以及沿江南—雪峰造山带发育的北东向的川东—湘鄂西弧形带。详细的构造解析、盆地沉积及物源特征综合分析表明,弧形构造不仅将早期的前陆序列卷入变形,并且控制了晚侏罗世—晚白垩世的盆地演化和古地理格局。总结扬子北缘晚造山阶段的盆山演化特征,可以将其划分为3个阶段:(1)晚侏罗世—早白垩世早期,大洪山和大巴山弧形带的发育控制了四川盆地东北部及秭归盆地上侏罗统蓬莱镇组的沉积,川东—湘鄂西弧形带限制了盆地的东南边界,加之位于四川盆地西部的龙门山逆冲带,三面围限构成具前渊沉降的克拉通内盆地或称为"墙围盆地"(walled sedimentary basin);(2)早白垩世中期—早白垩世晚期,大洪山和大巴山弧形带的逆冲构造变形逐渐减弱,而川东—湘鄂西弧形带继续向北西扩展,构造线呈北东向展布,在弧形带前缘的宜昌地区形成沉积中心,并覆盖了现今的黄陵背斜;(3)晚白垩世,川东—湘鄂西弧形带继续向北西推进,构造线呈北北东向展布,弧形带北翼的黄陵背斜初始隆起,沉积中心分别位于北翼宜昌地区及南翼习水地区。与此同时,在弧形带内部薄皮构造的向斜部位形成楔顶沉积,发育如恩施盆地、黔江盆地、来凤盆地等一系列规模较小的背驼式盆地。During the Late Jurassic to Late Cretaceous, the northern Yangtze area has evolved into a late-orogenic tectonic regime, which is characterized by the development of several thin-skinned foreland fold-thrust belts, including Dabashan, Dahongshan and eastern Sichuan-western Hunan and Hubei fold- thrust belts. They all show arc-shape geometries and generally trend parallel to the Qinling-Dabieshan Orogen and Xuefengshan Orogen. Synthesis of structural mapping, sedimentary facies and provenance an- alyses revealed that these arcuate fold-thrust belts not only deformed the original foreland sequence, but also controlled the basin evolution during the Late Jurassic through Late Cretaceous. Here we define the late-orogenic tectonic-paleogeography evolution into three phases as （1） From Late Jurassic to early Early Cretaceous： The Dahongshan and Dabashan fold-thrust belts initially propagated southwestwards and con- trolled the deposition of Penglaizhen Formation in northern Sichuan Basin and Zigui Basin. The original foreland basin was bounded by eastern Sichuan-western Hunan and Hubei fold-thrust belt to the southeast and Longmenshan fold-thrust belt to the west, leading to an intraeratonic basin with foredeep subsidence which is also referred as ＂walled sedimentary basin＂ （2） From middle Early Cretaceous to late Early Cretaceous： The propagation of the Dahongshan and Dabashan fold-thrust belts attenuated, while the east- ern Sichuan-western Hunan and Hube fold-thrust belt continued the northwestward propagation and formed the structural lines trending northeast. On the front of the eastern Siehuan-western Hunan and Hubei fold- thrust belt, the depocenter of the basin was located near Yichang city where the Huangling anticline has yet been exposed. （3） During the Late Cretaceous： The eastern Sichuan-western Hunan and Hubei fold- thrust belt propagated northwestly with slight change of the structural trends from northeast to north-north- east. The Huangling anticline was initially formed during th

关 键 词：弧形构造 前陆盆地 扬子北缘 背驼式盆地 

分 类 号：P547[天文地球—构造地质学]