北山辉铜山泥盆纪钾长花岗岩锆石U-Pb年龄、成因及构造意义

被引:55
作者
李舢
王涛
童英
王彦斌
洪大卫
欧阳志侠
机构
[1] 中国地质科学院地质研究所
关键词
锆石U-Pb年龄; 高分异I-A型花岗岩; Sr、Nd、Hf; 同位素; 构造环境; 北山造山带;
D O I
暂无
中图分类号
P588.121 [];
学科分类号
070901 ;
摘要
LA-ICP-MS锆石U-Pb定年结果表明,北山柳园地区辉铜山钾长花岗岩的形成年龄为397±3Ma(MSWD=1.1)。地球化学特征显示为高钾钙碱性的高分异I型花岗岩到A型花岗岩过渡的特征。其全岩εNd(t)值为-1.3~+1.2,Nd模式年龄(tDM)为960~1530Ma;锆石εHf(t)值为-1.0~+5.8,两阶段Hf模式年龄(tDM2)为1024~1455Ma。地质背景、地球化学和同位素综合分析显示,辉铜山岩体为造山后伸展拉张背景下,幔源岩浆底侵导致上覆年轻地壳(可能为洋壳、岛弧建造或增生楔物质)部分熔融形成的钙碱性花岗闪长质岩浆经进一步演化及结晶分异形成。北山南带地区早-中泥盆世花岗岩显示出高分异钙碱性I型花岗岩、I-A型花岗岩和A型花岗岩的组合特征。因此,在397Ma左右,北山地区古生代岩浆已经从I型或S型转化为I-A型特征,构造环境转化为后造山或同造山晚期的伸展环境。
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页码:3055 / 3070
页数:16
相关论文
共 53 条
[11]  
北山地区金属矿床成矿规律及找矿方向[M]. 地质出版社 , 聂凤军等著, 2002
[12]  
中朝板块北缘中段地壳演化[M]. 北京大学出版社 , 邵济安著, 1991
[13]  
Highly evolved juvenile granites with tetrad REE patterns: the Woduhe and Baerzhe granites from the Great Xing’an Mountains in NE China[J] . Bor-ming Jahn,Fuyuan Wu,R. Capdevila,F. Martineau,Zhenhua Zhao,Yixian Wang.LITHOS . 2001 (4)
[14]  
Phanerozoic crustal growth: U–Pb and Sr–Nd isotopic evidence from the granites in northeastern China[J] . Fu-yuan Wu,Bor-ming Jahn,Simon Wilde,De-you Sun.Tectonophysics . 2000 (1)
[15]  
Granitoids of the Central Asian Orogenic Belt and continental growth in the Phanerozoic[J] . Bor-ming Jahn,Fuyuan Wu,Bin Chen.Transactions of the Royal Society of Edinburgh: E . 2000 (1-2)
[16]  
Significance of Nb/Ta as an indicator of geochemical processes in the crust-mantle system[J] . Trevor H. Green.Chemical Geology . 1995 (3)
[17]   POST-COLLISIONAL ALKALINE GRANITES [J].
SYLVESTER, PJ .
JOURNAL OF GEOLOGY, 1989, 97 (03) :261-280
[18]  
A-type granites: geochemical characteristics, discrimination and petrogenesis[J] . Joseph B. Whalen,Kenneth L. Currie,Bruce W. Chappell.Contributions to Mineralogy and Petrology . 1987 (4)
[19]  
Geochemistry of eocene calc-alkaline volcanic rocks from the Kastamonu area, Northern Turkey[J] . Angelo Peccerillo,S. R. Taylor.Contributions to Mineralogy and Petrology . 1976 (1)
[20]  
Magmatism in the Ocean Basins. Sun SS, McDonough WF. . 1989