甘肃北山野马泉岩体同位素地球化学特征 |
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引用本文:范洪海,阂茂中,陈佳,季瑞利.2005.甘肃北山野马泉岩体同位素地球化学特征[J].地球学报,26(z1):78-83. |
DOI:10.3975/cagsb.2005.s1.26 |
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基金项目:本文为国防科工委放射性废物治理专项研究成果。 |
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中文摘要:Nd、Sr、Pb同位素研究结果揭示:甘肃北山野马泉岩体第Ⅰ、Ⅱ侵入阶段花岗岩类具有Ⅰ-型花岗岩的特征,(87Sr/86Sr)i=0.708~0.710,εNd=-2.229~-5.866,在207 Pb/204Pb-206Pb/204Pb构造模式图上其投影点落在造山带演化线附近,在εNd-εSr图解中,其投影点落人Ⅰ-型花岗岩类范围内,其成岩物质为壳幔混合来源。第Ⅲ侵人阶段的岩石成因类型为S-型,其(87Sr/86Sr)i=0.7149~0.7358, εNd=-7.3750~-8.9556。该岩体形成的地球动力学环境是北山陆内碰撞造山带。 |
中文关键词:Nd、Sr、Pb同位素 岩石成因 野马泉岩体 甘肃北山 |
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Isotopic Geochenical Characteristics of Yemaquan Granitic Intrusions in Beishan Area, Gansu Province |
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Abstract:Sm-Nd-Pb isotope compositions reveal that I-type granite characteristics of the Ⅰ、Ⅱ Yemaquan intrusions are as follows:(87Sr/86Sr)i=0.708~0.710, εNd=-2.2291~-5.8664,and the plot of 207Pb/204Pb versus 206Pb/204Pb is near and below the evolutionary curve of the orogenic belt. The granitoids are characterized by mixed (crust+mantle) origin of rock-forming materials.The Ⅲ granitoid is S-type granite, whose (87Sr/86Sr), are 0.7149-0.7358 andεNd are-7.3750~-8.9556. The geodynamic environment of the granitoids was the Beishan orogenic belt related to intercontinental collision, especially at the time when collision was drawing to its end. |
keywords:Sm-Nd-Pb isotope compositions petrogenesis Yemaquan granitic complex Beishan in Gansu Province |
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