SHRIMP U-Pb dating and Hf isotopic analyses of Middle Ordovician meta-cumulate gabbro in central Qiangtang, northern Tibetan Plateau

被引：18

作者：

ZHAI QingGuo1 WANG Jun1

2 College of Earth Sciences

3 The Geological Laboratory Center and State Key Laboratory of Geological Processes and Mineral Resources

机构：

来源：

Science China(Earth Sciences) | 2010年 / 53卷 / 05期

基金：

中国国家自然科学基金;

关键词：

Qiangtang; cumulate gabbro; SHRIMP dating; Hf isotope;

D O I：

暂无

中图分类号：

P597.3 [];

学科分类号：

070902 ;

摘要：

Metabasites consisting of metamorphic ultra-mafic rocks, cumulate gabbro, gabbro (diabase), basalt, and plagiogranite are exposed at the Taoxinghu area in central Qiangtang, northern Tibetan Plateau. Zircon SHRIMP U-Pb dating for the cumulate gabbro yields a weighted mean age of 467±4 Ma, which is the oldest and most reliable magmatic age in this area. Zircon 176Hf/177Hf ratios range from 0.282615 to 0.282657, with εHf(t) values of 5.02±0.28, indicating that the cumulate gabbro was mainly derived from the depleted mantle. In addition, geochemical data of metabasites suggest that they have similar characteristics to those in the mid-ocean ridge basalts (MORB). The Taoxinghu metabasites may represent the fragment of Early Paleozoic ophiolite in the "Central Uplift" of the Qiangtang, northern Tibetan Plateau.

引用

页码：657 / 664

页数：8

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