摘要
渤海湾盆地周缘发育的多个变质核杂岩,很好地记录了华北克拉通东部晚中生代以来的地壳伸展过程。文中以渤海湾盆地西部献县凸起和饶阳凹陷为研究区,试图揭示盆地内部变质核杂岩的发育特征。根据井、震结合的方法,通过精细的构造解释,厘定了献县断层及其上盘的构造变形特征;利用凹陷内的钻井资料对献县凸起上发育地层的时代和岩性进行限定;结合区域上变质核杂岩的发育特征和形成背景,讨论了献县变质核杂岩的发育时间和成因演化模式。结果表明:在研究区内呈弧形展布的献县断层具有主拆离断层的特征,断层上盘的饶阳凹陷南部残留有中元古界和下古生界,且凹陷内发育有数量众多、不同倾向的次级断层;献县凸起上发育的地层为太古宇-古元古界,岩性包括角闪片麻岩、黑云二长片麻岩,局部发育有花岗片麻岩。研究认为,献县变质核杂岩具有典型变质核杂岩的基本特征,其形成时间为晚中生代(K1?),发育于华北克拉通东部岩石圈大规模减薄的背景下,并以滚动枢纽模式发展演化。
A series of metamorphic core complexes developed around the Bohai Bay Basin recording the crustal stretching process of the eastern North China Craton since the Late Mesozoic.In order to reveal the characteristics of the metamorphic core complex developed in the basin,we selected the Xianxian High and southern Raoyang Sag as the study area.We determined the deformation characteristics of the Xianxian fault and its hanging wall through fine interpretation of the seismic and drilling data,and constructed the age and lithology of the strata developed on the Xianxian High using drilling data obtained from the southern Raoyang Sag.We discuss here the timing and genetic model of the Xianxian metamorphic core complex based on comprehensive consideration of its developmental characteristics and background in the North China Craton.Our study shows that (1)the curved Xianxian fault in the study area has the characteristics of the main detachment fault;(2)the southern Raoyang Sag,located in the hanging wall of the fault,shows residual Middle Proterozoic to Lower Paleozoic accompanied by numerous secondary faults with different dips in the sag;and (3)the Archean to Paleoproterozoic strata constitute the main part of the Xianxian High with lithology including hornblende,biotite monzonitic and localized granite gneisses.Overall,our results demonstrate that the Xianxian metamorphic core complex,formed in the Late Mesozoic (K1?),has the basic characteristics of a typical metamorphic core complex.It developed in the background of the largescale lithospheric thinning of the eastern North China Craton and evolved in accordance with the rolling- hinge model.
作者
单帅强
何登发
张煜颖
SHAN Shuaiqiang;HE Dengfa;ZHANG Yuying(School of Energy Resources,China University of Geosciences(Beijing),Beijing 100083,China;Wuxi Research Institute of Petroleum Geology,Research Institute of Petroleum Exploration and Production,SINOPEC,Wuxi 214126,China)
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2019年第1期178-188,共11页
Earth Science Frontiers
基金
国家重点研发计划项目(2017YFC0601405)
关键词
伸展构造
变质核杂岩
献县凸起
渤海湾盆地
extensional structures
metamorphic core complex
Xianxian High
Bohai Bay Basin
