[1]潘成泽,邱 林,叶现韬,等.扎河坝蛇绿岩锆石U-Pb年龄、Hf-O同位素组成及其地质意义[J].华东地质,2016,37(02):102-112.[doi:10.16788/j.hddz.32-1865/P.2016.02.004]
　PAN Cheng-ze,QIU Lin,YE Xian-tao,et al.Zircon U-Pb ages and Hf-O isotope compositions of the Zhaheba ophiolite in the northern margin of the Junggar terrane and their tectonic implications[J].East China Geology,2016,37(02):102-112.[doi:10.16788/j.hddz.32-1865/P.2016.02.004]
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扎河坝蛇绿岩锆石U-Pb年龄、Hf-O同位素组成及其地质意义()
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《华东地质》[ISSN:2096-1871/CN:32-1865/P]

卷:
37
期数:
2016年02期
页码:
102-112
栏目:
基础地质
出版日期:
2016-06-15

文章信息/Info

Title:
Zircon U-Pb ages and Hf-O isotope compositions of the Zhaheba ophiolite in the northern margin of the Junggar terrane and their tectonic implications
文章编号:
2096-1871(2016)02-106-07
作者:
潘成泽1; 邱 林1; 叶现韬2; 董永观2
(1.新疆维吾尔自治区人民政府国家三〇五项目办公室,乌鲁木齐 830000)
(2.南京地质矿产研究所,南京 210016)
Author(s):
PAN Cheng-ze1;  QIU Lin1;  YE Xian-tao2;  DONGYong-guan2
(1. National 305 Project Office, Urumqi 830000, China)
(2. Nanjing Institute of Geology and Mineral Resources, Nanjing 210016, China)
关键词:
扎河坝;  蛇绿岩;  年龄;  同位素;  地质意义
Keywords:
Zhaheba ophiolite;  MORB-type;  accretion process;  Central Asia Orogenic Belt(CAOB);  Junggar terrane.
分类号:
P597
DOI:
10.16788/j.hddz.32-1865/P.2016.02.004
文献标志码:
A
摘要:
扎河坝蛇绿岩位于准噶尔北缘,是扎河坝—阿尔曼太蛇绿混杂岩带的一部分。通过对蛇绿混杂岩中堆晶辉长岩和凝灰岩夹层的锆石U-Pb年龄及Hf-O同位素进行研究,获得堆晶辉长岩的结晶年龄为485±4Ma,凝灰岩的喷发年龄为401±2.5Ma。辉长岩极度亏损Hf同位素,εHf(t)为13～20,δ18O峰值为+5.37‰,显示其具有地幔特征。凝灰岩锆石的Hf同位素亏损程度低于堆晶辉长岩,εHf(t)为1.4～9.2。扎河坝蛇绿岩具有典型的SSZ型蛇绿岩特征,是通过俯冲增生到洋内弧弧前的蛇绿岩。
Abstract:
The Zhaheba ophiolite, located in the northern margin of Junggar terrane, is part of the Zhaheba-Aerman ophiolitic melange belt. Through U-Pb zircon age and Hf-O composition analysis for two samples from the ophiolitic melange belt, this study obtained a crystallization age of 485±4Ma for cumulate gabbros and an eruptive age of 401±2.5Ma for tuffs. The gabbros are characterized by extreme depletion of Hf isotopic composition with εHf(t)of 13～20 and δ18O peak value of +5.37‰, indicating a mantle-sourced feature. Hf isotope depletion degree of zircons from the tuffs is lower than that from cumulate gabbros, with εHf(t)of 1.4～9.2. All this features suggest that the Zhaheba ophiolite is of typical characteristic of the SSZ type ophiolite, which results from subduction accretion to the front of intra-oceanic arc.

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备注/Memo

备注/Memo:
基金项目:十二五国家三GA996铠祎目“成矿动力学背景和成矿过程研究”(项目编号:2011BAB06B03-01)。第一作者简介:潘成泽,1964年生,男,地质矿产高级工程师,从事地质矿产调查研究和科技管理工作。
更新日期/Last Update: 2016-06-17