抚州盆地晚中生代‒新生代构造变形特征、形成背景及地质意义  

Late Mesozoic-Cenozoic Deformation Characteristics of the Fuzhou Basin and its Regional Tectonic Settings and Significances

作　　者：曾广乾 陈柏林[1,2] 申景辉 高允 ZENG Guangqian;CHEN Bailin;SHEN Jinghui;GAO Yun(Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;MNR Key Laboratory of Paleomagnetism and Tectonic Reconstruction,Beijing 100081,China;Hunan Institute of Geology Survey,Changsha 410016,Hunan,China)

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]自然资源部古地磁与古构造重建重点实验室,北京100081 [3]湖南省地质调查院,湖南长沙410016

出　　处：《大地构造与成矿学》2021年第6期1094-1110,共17页Geotectonica et Metallogenia

基　　金：国家重点研发计划项目(2017YFC0602602,2016YFC0600207);中国地质科学院地质力学研究所基本科研业务费专项(JYYWF20180602,DZLXJK201904)联合资助。

摘　　要：抚州盆地是叠加在赣杭构造带上的一个NE向晚白垩世‒古近纪陆相断陷盆地。通过对盆地内不同产状与运动学性质的小型断裂、节理和褶皱的构造解析,识别出三期构造应力场,并结合中新生代中国东部构造演化背景,厘定盆地构造变形序列及其动力学背景:第一期NW-SE向引张为成盆期同构造伸展,可能与古太平洋板块俯冲过程中的板片后撤引发的弧后扩张作用有关;第二期NNW-近SN向挤压控制了新余组的沉积,可能与古近纪早期印度板块北向运移与欧亚大陆间的碰撞作用有关;第三期NE-SW向挤压事件可能与赣江断裂带右行走滑所派生的局部挤压应力场有关,其动力背景可能为古近纪中晚期印度板块对欧亚板块碰撞引发青藏高原物质向东逃逸。综合前人研究资料,推断相山铀矿田内的NE向邹家山‒石洞断裂并非导矿、容矿构造,可能形成于古近纪早期的NNW-近SN向挤压作用,属成矿后构造。相山地区晚白垩世‒古近纪早期的快速隆升及东西部的差异隆升是这一时期以断陷红盆为标志的地壳伸展与重力均衡调整作用的结果,抚州盆地现今的展布格局可能为晚期NE向构造挤压导致的地块差异隆升剥蚀所控制。The Fuzhou basin is a late Cretaceous-Paleogene NE-trending continental graben basin,which was superimposed on the Gan-Hang tectonic belt.Based on the structural analysis of faults,joints and folds of different occurrences and kinematic properties in the basin,three stages of tectonic stress fields are identified.Combined with the tectonic evolution backgrounds of Eastern China in the Mesozoic and Cenozoic,the tectonic deformation sequences and their dynamic backgrounds of the basin are determined:the first stage of NW-SE-trending extension was the syntectonic extension in the basin forming period,which may be related to the back-arc spreading caused by the plate retreat during the subduction of the Paleo Pacific Plate;the second stage NNW-SN-trending compression controlled the deposition of the Xinyu Formation,which may be related to the northward migration of the Indian Plate in the early Paleogene and the collision with the Eurasia Plate;the third stage of NE-SW-trending compression event may be related to the local compressive stress field derived from the right lateral strike slipping of the Ganjiang fault zone,and its dynamic background may be the eastward escape of the Tibetan Plateau caused by the collision between the Indian and Eurasian plates in the middle to late Paleogene.Based on previous studies,it is inferred that the NE-trending Zoujiashan-Shidong fault in the Xiangshan uranium orefield is not an ore conducting and ore hosting structure,but might have been formed in the NNW-SN-trending compression in the early Paleogene,which belongs to the post metallogenic structures.Moreover,the rapid uplift and differential uplift of the east and the west parts of the Xiangshan area in the Late Cretaceous to the early Paleogene were the results of crustal extension and gravity isostatic adjustment marked by the graben basin in this period.It is further considered that the present distribution pattern of the Fuzhou basin may be controlled by the differential uplift and denudation caused by the late NE-trending

关 键 词：中新生代 构造变形 构造应力场 铀成矿 抚州盆地 

分 类 号：P542[天文地球—构造地质学]