Petrography of the Metamorphic Pillow Basalt and SHRIMP U-Pb Dating of Zircons from the Intruding Trondhjemite in Archean Taishan “ Group” ,  Western Shandong  Province

• 责任者：Wang Wei (Institute of Geology ; Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Yang Enxiu
• 刊名：Geological Review
• 出版年：2009
• 卷期：55(5)
• 关键词：变玄武岩 ; metabasalt ; 奥长花岗岩 ; trondhjemite ; 泰山 ; Taishan Mountains
• 页码：p.737-744
• 图表：3 illus., 2 tables, 26 refs.
• 分类号：0802
• issnNo：ISSN0371-5736
• isbnNo：CN11-1952/P

///Typical metamorphic pillow basalt is widely distributed in the Liuhang “ Formation” of the Taishan “Group” ,   west of Tuanyuangou village,   Zhangqiu,   western Shandong Province. The pillows,   interstitial filled with silica and carbonate, exhibit blastoporphyritic texture. The cement mainly consists of plagioclase,   zoisite,   hornblende,   chlorite and quartz. The porphyroblasts, ususlly smaller than 0.5 mm in size, are mainly composed of plagioclase, zoisite and chlorite.   Electron microprobe analysis shows that, in the pillows, most albites (with An <10) in matrix,   are formed during green schist facies metamorphism, but some plagioclase phenocrysts (with An >30) still remain. A SHRIMP U-Pb zircon age of (2707 ±9) Ma was obtained for a gneissic trondhjemite, which intrudes in the Liuhang “ Formation” ,   limiting the formation age of the Taishan “ Group”  no younger than 2.  71 Ga.