Macrocrystal Garnet and Its Inclusions in Kimberlite Pipes from the Mengyin Area, Shandong Province, China

作     者：WANG Lijuan ZHAO Lei DING Yifei HAO Jinghua LI Youzhi MA Junhong LI Yuanyuan ZHANG Xiaoli 

作者机构：National Laboratory of Mineral Materials State Key Laboratory of Geological Processes and Mineral Resources and School of Marine Sciences China University of Geosciences Beijing 100083 China National Gemstone Testing Center Beijing 100013 China Development ＆ Research Center China Geological Survey Beijing 100083 China Jinyuan Mining Technology Center Lingbao Henan 472500 China 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2010年第84卷第1期

页      面：167-177页

核心收录：

学科分类：0709[理学-地质学] 081803[工学-地质工程] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 08[工学] 0708[理学-地球物理学] 0818[工学-地质资源与地质工程] 

基　　金：supported by the National Natural Science Foundation of China (Grant No. 4027301) the National Geological Survey Project (Grant No.003201) 

主　　题：macrocrystal garnet inclusion mantle fluid electric microprobe technique (EPMA) 

摘      要：Based on previous studies of kimberlite xenoliths and diamond inclusions in this region, macrocrystai garnet was analyzed with the electric microprobe technique （EPMA）. The garnet is collected from the Shengli No.1 kimberlite pipe in the Mengyin area of Shandong Province, China. The results indicate that the garnet contains two kinds of multiphase inclusions： one is K-, B-, and CI- bearing oxygen-free phase, K- and Cl-bearing oxygen-free phase, and volatile-bearing garnet inclusions （in1 and in3）; and the other is chlorite, phlogopite, apatite and calcite （in2）. It is suggested that the formation of garnet and its inclusions is associated with strongly reduced mantle fluid. Such a fluid was transformed from ultra-deep high-reduction oxygen-free fluid into low-reduction alkaline fluid, and finally into oxidized fluid with low oxygen fugacity. This result confirms that the Mengyin area underwent metamorphism of slightly active deep fluid, and provides evidence for searching diamond by means of indicative minerals.