Timing of granite pegmatite-type high-purity quartz deposit in the Eastern Qinling, China: constraints from in-situ LA-ICP-MS trace analyses of quartz and monazite U–Pb dating
Timing of granite pegmatite-type high-purity quartz deposit in the Eastern Qinling, China: constraints from in-situ LA-ICP-MS trace analyses of quartz and monazite U–Pb dating
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DOI：
10.1007/s11631-021-00505-y
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发表时间：
2021-11
期刊：
影响因子：
1.6
通讯作者：
Yong Zhang;Hai Zhao;Lei Liu;Jiayong Pan;Likuan Zhu;Guoqi Liu;Xiaotian Zhang
中科院分区：
文献类型：
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作者：
Yong Zhang;Hai Zhao;Lei Liu;Jiayong Pan;Likuan Zhu;Guoqi Liu;Xiaotian Zhang
东秦岭中国是我国重要的稀有金属成矿省之一，花岗伟晶岩脉广泛分布。5号花岗伟晶岩侵入秦岭群花岗片麻岩，主要矿物为石英(39.8%)、钾长石(18.8%)、钠长石(36.3%)、白云母(3.4%)和石榴石(1.1%)。独居石U-Pb同位素测年结果表明，东秦岭5号伟晶岩的侵位年龄约为420.2 ± 2.2a，证实高纯石英矿化可能形成于早泥盆世。激光烧蚀电感耦合等离子体质谱分析表明，东秦岭地区的石英样品中总微量元素(Al、Ti、Sc、Li、B、Cr、Mn、Fe)含量在23.2~52.8ppm之间，略高于北卡罗来纳州西部云杉松高纯石英矿的石英含量(杂质元素含量在13.4~25.9ppm之间)。东秦岭5号伟晶岩可确定为中国的高纯石英矿床。
Eastern Qinling, China is one of the important rare metal metallogenic provinces with extensively distributed granite pegmatite dikes. The No. 5 granite pegmatite intruded into the granitic gneiss of the Qinling Group, and the major minerals are quartz (39.8%), K-feldspar (18.8%), albite (36.3%), muscovite (3.4%), and garnet (1.1%). Monazite U–Pb isotopic dating indicates that the No. 5 pegmatite from the Eastern Qinling was emplaced at ca. 420.2 ± 2.2 Ma, which confirms that high-purity quartz mineralization probably formed during the Early Devonian. In-situ laser ablation inductively coupled plasma mass spectrometry analysis of quartz show that quartz samples from Eastern Qinling have total trace element concentrations (Al, Ti, Sc, Li, B, Cr, Mn, and Fe) ranging from 23.2 to 52.8 ppm, slightly higher than the quartz (impurity element content from 13.4 to 25.9 ppm) of the Spruce Pine high-purity quartz deposit in western North Carolina. The No. 5 pegmatite of Eastern Qinling could be defined as one high-purity quartz deposit of China.