| 赵亮亮,郑崔勇,程晓艳,石建国,王钊飞.青海泽库县晚三叠世尼玛隆—甘千花岗岩体地球化学特征及构造环境探讨[J].矿产勘查,2019,(3):458-465 |
| 青海泽库县晚三叠世尼玛隆—甘千花岗岩体地球化学特征及构造环境探讨 |
| Disussion on geochemical characteristics and structural environment of the Niemalong-ganqian granite in late triassic in Zeku area,QingHai |
| 投稿时间：2018-04-24 |
| DOI： |
| 中文关键词: 尼玛隆—甘千花岗岩体 地球化学特征 构造环境 青海泽库 |
| 英文关键词: Nimalong-Ganqian granite,geochemical characteristics,structural environment, Zeku, Qinghai |
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| 中文摘要: |
| 研究区位于青藏高原东北缘,西秦岭、祁连、东昆仑3个造山带的交汇部位,大地构造位置属印支造山带,同德—泽库弧后前陆盆地。岩浆活动以印支期中酸性岩浆岩最为发育。对该区晚三叠世尼玛隆—甘千花岗岩体利用LA-ICP-MS方法进行了锆石U-Pb同位素测年获得(225.9±1)Ma年龄值,表明岩体侵位于晚三叠世。岩石主量元素特征反应出明显的富碱、富钾特征,属中酸性岩体。岩体富集轻稀土,L/HREE=7.56～13.02,平均10.17；δEu=0.47～0.84,平均0.69,表明岩浆过程主要受部分熔融作用控制。微量元素分析显示岩体富集大离子亲石元素,花岗岩形成与同碰撞构造环境密切相关。初始岩浆的原岩来自早期岛弧火山岩的部分熔融,并且继承了早期岛弧火山岩的部分地球化学特征。 |
| 英文摘要: |
| The research area is located at the northeast edge of Qinghai-Tibet plateau, where is the intersection of the three orogenic belts (the West Qinling, Qilian Mountain and East Kunlun). The geotectonic position belongs tothe Indo-Chinese orogenic belt and the foreland basin along Tonged-Zuku arc. Where the magmatic activities are majored as the movements of theIndo-Chinese intermediate-acid magmatic rocks. By using the LA-ICP-MS dating method,the obtained U-Pb ageof the late Triassic granites inNimalong-Ganqianarea is(225.9±1)Ma, suggesting that these granites formed in late Triassic epoch. The characteristic of the mainelements of the rock reflects obvious enrichment of alkali and potassium,so that the rock is a medium acid rock. The granite rock is rich in light rare earth element(L/HREE=7.56-13.02, average10.17) and Eu(δEu=0.47-0.84,average0.69), indicate that the magmatic process is mainly controlled by partial melting. The result of analysis on the microelement shows that the rock mass is relatively rich in large ionic lithophile elementsand the formation of granite is closely related to the collisional tectonic environment. The original rock of the initial magma comes from partial melting of the early island arc volcanic rock and inherits some of the geochemical characteristics of the early island arc volcanic rocks. |
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