Hf isotopes of the 3.8 Ga zircons in

Hf isotopes of the 3.8 Ga zircons in eastern Hebei Province, China: Implications for early crustal evolution of the Nort

Zircon U-Pb dating indicates that the fuchsite quartzite in eastern Hebei Province was derived from weathering and erosion of the 3.6-3.8 Ga granitic rocks. In-situ zircon Hf analyses show that the Lu-Hf isotopic system remained closed during later thermal disturbances. Zircons with concordant ages have Hf isotopic model ages of about 3.8 Ga, suggesting a recycling of this ancient crust. The ～3.8 Ga zircons have similar Hf isotopic compositions to those of chondrite, indicating that their source rocks (granitic rocks) were derived from partial melting of the juvenile crust which originated from a mantle without significant crust-mantle differentiation. Therefore, it is proposed that there was no large-scale crustal growth before ～3.8 Ga in eastern Hebei Province. Considering zircon Hf isotopic data from other areas, it is concluded that the most ancient crust in the North China Craton probably formed at about 4.0 Ga, and the possibility to find crust older than 4.0 Ga is very limited.

作 者： WU Fuyuan YANG Jinhui LIU Xiaoming LI Tiesheng XIE Liewen YANG Yueheng   作者单位： WU Fuyuan,YANG Jinhui,LI Tiesheng,XIE Liewen,YANG Yueheng(State Key Laboratory of Tectonic Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China)

LIU Xiaoming(Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China) 

刊 名： 科学通报（英文版）  SCI 英文刊名： CHINESE SCIENCE BULLETIN  年，卷(期)： 2005 50(21)  分类号： P5  关键词： Hf isotope   zircon   ancient crust   North China Craton  

【Hf isotopes of the 3.8 Ga zircons in】相关文章：

Identification of 3.5 Ga detrital zircons from Yangtze craton in south China and the implication for Archean crust evolu04-26

水稻GA受体的同源基因在玉米中的扩增04-27

GA3处理对仙客来种子萌发的影响04-27

基于遗传算法(GA)的具有约束的飞行轨迹规划04-27

基于GA的带终端约束的变结构末制导律设计04-27

基于相空间重构和GA-BP网络的径流预测04-26

高存储空间奠定高摄录品质Canon HF1104-26

3.8妇女活动简报02-19

基于GA-AIC的路面检测信息多元回归模型优选04-27

DF/HF化学激光器关键技术研究状况评析04-27