摘要
辽东半岛广泛分布变质核杂岩构造,作为华北克拉通破坏的浅部响应,具有重要的构造演化研究意义.新房变质核杂岩是近年来新发现的伸展构造单元,具备典型的三层结构:上盘主要包括新元古代-古生代弱变形沉积岩层和早白垩世庄河断陷盆地,下盘包括新太古代变质基底和同构造中生代花岗质侵入岩体,二者接触部位为拆离断层带.野外宏观运动学及显微构造特征明显,均指示上盘具由SEE向NWW的运动学特征,与太平洋板块早白垩世早-中期运动方向相吻合.本次工作通过锆石LA-ICP-MS U-Pb同位素及常量、稀土和微量元素测试,将新房变质核杂岩的形成时代大致限定于早白垩世早期(123~125 Ma),并进一步明确为华北克拉通破坏事件的早期产物.该变质核杂岩控制了区内新房大型金矿的生成,在辽东半岛变质核杂岩控矿、成矿较差的现状下,研究意义较大.
As shallow responses to the destruction of North China craton,metamorphic core complex structures,which are widely distributed in Liaodong Peninsula,are of great significance to study the regional tectonic evolution.Xinfang metamorphic core complex is a newly discovered extensional unit with typical 3-layers structure.The hanging wall includes weakly deformed sedimentary strata from Neoproterozoic to Paleozoic and Zhuanghe faulted basin formed in Early Cretaceous.The footwall includes Archean metamorphic rocks and Mesozoic syntectonic granitic intrusive rocks.The contact relationship between the hanging wall and footwall is a detachment fault zone.The macroscopic characteristics in the field and microstructural characteristics under the microscope are obvious,indicating that the hanging wall has the kinematical characteristic from SEE to NWW,which is consistent with the movement direction of the Pacific plate during the early and middle period of Early Cretaceous.Using the method of LAICP-MS U-Pb isotope testing on zircons and testing of major,rare earth and trace elements,the forming age of the Xinfang metamorphic core complex is approximately limited to the early stage of Early Cretaceous(123-125 Ma),and the complex is regarded as a product of the destruction of the North China craton.The metamorphic core complex controls the formation of Xinfang large-scale gold deposit,and the research on the complex is of great significance under the situation that present complexes in Liaodong Peninsula have weak relationship with gold mineralization.
作者
张璟
杨中柱
成龙
王宇利
李伫民
杨仲杰
骆念岗
马维
王然
Patrice Rey
Zhang Jing;Yang Zhongzhu;Cheng Long;Wang Yuli;Li Zhumin;Yang Zhongjie;Luo Niangang;Ma Wei;Wang Ran;Patrice Rey(Shenyang Institute of Geology and Mineral Resources,China Geological Survey,Shenyang 110034,China;Liaoning Geological and Mineral Survey Institute Company Limited,Shenyang 110034,China;Liaoning Provincal Institute of Geological Exploration Company Limited,Dalian 116100,China;The University of Sydney,Sydney NSW2006,Australia)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2020年第11期4014-4026,共13页
Earth Science
基金
国家重点研发计划项目(No.2018YFC0603800)
中国地质调查局项目(No.DD20190156)
国家自然科学基金项目(No.42072104)。
关键词
变质核杂岩
拆离断层
新房金矿
克拉通破坏
辽东半岛
矿床学
metamorphic core complex
detachment fault
Xinfang gold deposit
destruction of North China craton
Liaodong Peninsula
mineral deposits
