| 大兴安岭东北部霍龙门地区中侏罗世花岗岩——锆石U-Pb年龄、地球化学特征及构造意义 |
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| 引用本文： | 徐文喜,李成禄.大兴安岭东北部霍龙门地区中侏罗世花岗岩——锆石U-Pb年龄、地球化学特征及构造意义[J].地质与资源,2018,27(6):522-530. |
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| 作者姓名： | 徐文喜 李成禄 |
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| 作者单位： | 黑龙江省地质调查研究总院, 黑龙江哈尔滨 150036 |
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| 基金项目： | 中国地质调查局"黑龙江多宝山地区矿产远景调查"项目（1212010781024）；黑龙江国土科研项目"黑龙江省嫩江-黑河构造混杂岩地区成矿规律研究与找矿预测"（201603） |
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| 摘 要： | 霍龙门地区位于兴蒙造山带东部的兴安地块和松嫩地块接触带上，区内花岗岩类以晚古生代花岗岩为主，同时还有一定量的中生代花岗岩，岩性为二长花岗岩、花岗闪长岩、石英二长岩和碱长花岗岩等.二长花岗岩的SHRIMP锆石U-Pb定年结果为175.2±2.2 Ma，表明其形成于中侏罗世.该时代岩石的主量元素具有高钾、富钠、略富铝、低镁和贫磷贫钙的特征；微量元素表现出U、Th、Zr、Ta、Rb明显富集，而Ba、Sr、Nb、P、Ti明显亏损；稀土元素含量相对偏低，具有轻稀土元素相对富集、重稀土元素相对亏损的特征，有较弱的负Eu异常，轻重稀土元素分馏程度较强.岩石总体上属于高钾钙碱性系列花岗岩.花岗岩的R1-R2构造环境判别图解与微量元素Rb-（Yb+Nb）、Rb-（Yb+Ta）构造环境判别图解显示，该期发育的中侏罗世花岗岩处于同碰撞期到造山期后的构造环境.结合区域花岗岩展布特征及反映的构造环境综合认为，研究区内中侏罗世花岗岩应处于蒙古-鄂霍次克洋闭合后陆-陆碰撞环境.
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| 关 键 词： | 花岗岩 锆石U-Pb年龄 地球化学 霍龙门地区 大兴安岭 |
| 收稿时间： | 2018-03-09 |
MIDDLE JURASSIC GRANITES IN HUOLONGMEN AREA,NORTHEASTERN DAXINGANLING MOUNTAINS: Zircon U-Pb Age,Geochemistry and Tectonic Implications |
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| XU Wen-xi,LI Cheng-lu.MIDDLE JURASSIC GRANITES IN HUOLONGMEN AREA,NORTHEASTERN DAXINGANLING MOUNTAINS: Zircon U-Pb Age,Geochemistry and Tectonic Implications[J].Geology and Resources,2018,27(6):522-530. |
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| Authors: | XU Wen-xi LI Cheng-lu |
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| Institution: | Heilongjiang Institute of Geological Survey, Harbin 150036, China |
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| Abstract: | The Huolongmen area, tectonically located at the junction of Songnen and Xing'an blocks in the eastern Daxinganling-Mongolian orogenic belt, is dominated by the Late Paleozoic granite with a certain amount of Mesozoic granite, lithologically composed of monzogranite, granodiorite, quartz monzonite and alkali-feldspar granite. The zircon U-Pb age of 175.2±2.2 Ma of the monzogranite indicates the Middle Jurassic formation. The major elements of the rock are characterized by high K, rich Na, slightly rich Al, low Mg, and poor P and Ca. The trace elements show obvious enrichment of U, Th, Zr, Ta and Rb, and depletion of Ba, Sr, Nb, P and Ti. The REE content is relatively low, enriched in LREEs and depleted in HREEs with weak negative Eu anomaly and high degree of fractionation. The granites generally belong to high-K calc-alkaline series. The R1-R2 and Rb-(Yb+Nb), Rb-(Yb+Ta) diagrams reflect that the Middle Jurassic granite was formed in the tectonic environment from syn-collision to postorogenic stage. Combined with the distribution characteristics and tectonic setting of regional granites, it is thought that the Middle Jurassic granite in the study area was a product of continent-continent collision after the closure of Mongolia-Okhotsk Ocean. |
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| Keywords: | granite zircon U-Pb age geochemistry Huolongmen area Daxinganling Mountains |
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