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   作者單位： 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： 科學(xué)通報(bào)（英文版）  SCI 英文刊名： CHINESE SCIENCE BULLETIN  年，卷(期)： 2005 50(21)  分類號： P5  關(guān)鍵詞： Hf isotope   zircon   ancient crust   North China Craton  

【Hf isotopes of the 3.8 Ga zircons in】相關(guān)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受體的同源基因在玉米中的擴(kuò)增04-27

GA3處理對仙客來種子萌發(fā)的影響04-27

基于遺傳算法(GA)的具有約束的飛行軌跡規(guī)劃04-27

基于GA的帶終端約束的變結(jié)構(gòu)末制導(dǎo)律設(shè)計(jì)04-27

基于相空間重構(gòu)和GA-BP網(wǎng)絡(luò)的徑流預(yù)測04-26

高存儲空間奠定高攝錄品質(zhì)Canon HF1104-26

3.8婦女活動簡報(bào)02-19

基于GA-AIC的路面檢測信息多元回歸模型優(yōu)選04-27

DF/HF化學(xué)激光器關(guān)鍵技術(shù)研究狀況評析04-27