地质与勘探2017，Vol.53Issue(6)：1115-1128,14.
内蒙古苏尼特右旗白垩纪A型花岗岩锆石U-Pb年龄、地球化学特征及其构造意义
Zircon U-Pb Ages, Geochemical Characteristics and Tectonic Significance of the Cretaceous A-Type Granites in Sunite Youqi, Inner Mongolia
摘要
Abstract
The granitic rocks of Sunite Youqi Aobaotu, located in the middle of the Xing'an Mongolia orogenic belt, are composed of monzonitic gran-ite and syenogranite. The LA-ICP-MS zircon U-Pb ages of monzonitic granite and syenogranite are 143. 37 ± 0. 83Ma and 142. 58 ± 0. 61Ma, re-spectively, belonging to Early Cretaceous, which represent the most extensive magmatic activity in Yanshanian period. All samples are characterized by high silicon (71. 68% ~ 76. 65%), high alkali (7. 51% ~ 9. 01%), low aluminum (12. 01% ~ 14. 10%), high iron, low calcium and magnesi-um. They are thus classified as high-K calcium alkaline - alkaline transition series. These samples exhibit medium REE abundance and LREE enrich-ment. They also show LILE enrichment ( Ta,Zr,Hf) ,HFSE depletion ( Ba,Sr,P,Ti) and enrichment of ( Nd,Ta,Zr,Hf) . These features are similar to the typical A1 -type intraplate granites, which may be attributed to the upwelling of the asthenosphere in the extensional environment of the lithosphere, and the magma contaminated by the upper crust.关键词
敖包吐岩体/年代学/地球化学/A型花岗岩/板内伸展/苏尼特右旗/内蒙古Key words
Aobaotu granite/chronology/geochemistry/A-type granite/intraplate extensional/Sunite Youqi/Inner Mongolia分类
天文与地球科学引用本文复制引用
龙舟,来林,张学斌,张明洋,周长红..内蒙古苏尼特右旗白垩纪A型花岗岩锆石U-Pb年龄、地球化学特征及其构造意义[J].地质与勘探,2017,53(6):1115-1128,14.基金项目
中国地质调查局内蒙古1:5万敖如斯台(编号:K49E004013)、包饶勒敖包(编号:K49E004014)等六幅区域地质调查项目 . （编号:K49E004013）
