地质学报（英文版）2005，Vol.79Issue(5)：654-661,8.
SHRIMP Age of Exotic Zircons in the Mengyin Kimberlite, Shandong, and Their Formation
SHRIMP Age of Exotic Zircons in the Mengyin Kimberlite, Shandong, and Their Formation
摘要
Abstract
Due to various courses of formation of zircons from kimberlites, different kinds of zircons can provide useful information about the mantle and the crystallization of kimberlites. We chose 9 typical ones out of 33 zircons from the Shengli-1 kimberlite pipe in Mengyin County, Shandong Province to study their ages and formation by means of SHRIMP,CL, Raman spectroscopy, etc. The result shows that the 207pb/206Pb ages of many zircons vary from 2567±13 Ma to 2636±42 Ma, which are close to the age of Archaean granitoid (2457.3±47 Ma) in the study area. The contents of U and Th in the samples are higher than those of zircons crystallized in kimberlite and vary from 89 to 398 ppm as well as from 10 to 283 ppm. Color zones are obvious in these samples under the CL. The inclusions are composed of feldspar, quartz, apatite,etc. The above results show that the zircon samples came from the crust of the earth, which means that the kimberlite magmas are contaminated by crustal substances. The position where a great deal of volatile escapes and even explodes during rapid rise of magmas is located at the boundary of the ancient basement and the Precambrian stratum.关键词
kimberlite/exotic zircons/ages/SHRIMP/contamination/ShandongKey words
kimberlite/exotic zircons/ages/SHRIMP/contamination/Shandong分类
天文与地球科学引用本文复制引用
..SHRIMP Age of Exotic Zircons in the Mengyin Kimberlite, Shandong, and Their Formation[J].地质学报（英文版）,2005,79(5):654-661,8.基金项目
This study was supported by the National Natural Science Foundation of China (40272021) and the Outstanding Young Teachers Project of China University of Geosciences (CUGQNL0319). （40272021）
