In-Situ U-Pb Dating of Zircons from High-Pressure Granulites in Shandong Peninsula, Eastern China and Its Geological Significance

详细信息   

• 责任者：Liu Pinghua (Institute of Geology ; Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Liu Fulai
• 刊名：Earth Science Frontiers
• 出版年：2011
• 卷期：18(2)
• 关键词：麻粒岩 ; granulite ; 铀—铅计时 ; U-Pb dating ; 山东半岛 ; Shandong Peninsula
• 页码：p.33-54
• 图表：14 illus., 7 tables, 48 refs.
• 分类号：0802
• 出版序号：20120179
• issnNo：ISSN1005-2321
• isbnNo：CN11-3370/P

摘要

 High-pressure (HP) granulites as enclaves and irregular vein-like blocks are widely distributed in TTG gneisses of the Early Precambrian metamorphic basement of Shandong Peninsula, in the southeast of the North China Craton. Zircon grains separated from HP granulites are subdivided into three main types based on cathodoluminescence (CL), Laser Raman spectroscopy and in-situ U-Pb dating.  They are inherited (magmatic) zircon, HP metamorphic zircon and retrogressive zircon. This result indicates that Mesoarchean and Neoarchean igneous protoliths of mafic HP granulites, together with their TTG country rocks and meta-sedimentary rocks are subducted to coeval Paleoproterozoic HP metamorphism (1 850~1 900 Ma), followed by late medium-and low-granulites-facies retrogression (1 820~1 840 Ma). This new result is of very important significance for deeply discussing the genetic mechanism and geodynamic model of the HP granulites distributed in the southeast part of North China Craton.