| 大兴安岭多宝山地区晚古生代碱长花岗岩锆石U-Pb年龄：对兴安和松嫩地块碰撞拼合时间的限定 |
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| 引用本文： | 贾旭,任俊光,徐文坦,马虎超,张超,石国明.大兴安岭多宝山地区晚古生代碱长花岗岩锆石U-Pb年龄：对兴安和松嫩地块碰撞拼合时间的限定[J].中国地质,2022,49(2):586-600. |
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| 作者姓名： | 贾旭 任俊光 徐文坦 马虎超 张超 石国明 |
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| 作者单位： | 1. 成都理工大学地球科学学院;2. 防灾科技学院地球科学学院;3. 金川集团股份有限公司龙首矿;4. 西南石油大学地球科学与技术学院;5. 黑龙江省地质调查研究总院 |
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| 基金项目： | 中国地质调查局项目（DD20160047-07）资助~~； |
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| 摘 要： | 【研究目的】大兴安岭多宝山地区位于兴蒙造山带东部的兴安地块与松嫩地块之间的构造带上，区内构造演化复杂，岩浆活动频繁，本文通过对多宝山地区晚古生代碱长花岗岩的年代学和岩石地球化学研究，旨在约束兴安地块与松嫩地块碰撞拼合的时限。【研究方法】开展了LA-ICP-MS锆石U-Pb测年和岩石主微量元素的测试分析工作。【研究结果】测年获得的2件样品的加权平均年龄分别为（300.3±2.0）Ma和（307.3±1.7）Ma，属晚石炭世。岩石具有高硅SiO2=69.70%～77.42%，相对富铝Al2O3=11.60%～15.05%，富钾和钠（K2O=4.09%～5.67%;Na2O=3.13%～4.13%），贫钙和镁（CaO=0.02%～0.8%; MgO=0.02%～0.48%）的特征；微量元素表现出富集Rb、Th、Zr和Hf，亏损Ba、Sr、Nb和Ta,（Zr+Nb+Ce+Y）含量较高，平均值为529.10×10-6；稀土元素配分模式呈右倾，具明显Eu负异常；同时岩石具有较高的锆石饱和温度，符合A型花岗岩的特征。【结论】结合区域构...
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| 关 键 词： | 晚古生代 碱长花岗岩 年代学 地球化学 构造环境 地质调查工程 多宝山地区 大兴安岭 |
| 收稿时间： | 2019/11/9 0:00:00 |
| 修稿时间： | 2022/3/21 0:00:00 |
Zircon U-Pb dating of Late Paleozoic alkali-feldspar granite in Duobaoshan, Daxing' anling Mountains: Constrains on collision and assembly time of Xing'an and Songnen Blocks |
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| JIA Xu,REN Junguang,XU Wentan,MA Huchao,ZHANG Chao,SHI Guoming.Zircon U-Pb dating of Late Paleozoic alkali-feldspar granite in Duobaoshan, Daxing' anling Mountains: Constrains on collision and assembly time of Xing'an and Songnen Blocks[J].Chinese Geology,2022,49(2):586-600. |
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| Authors: | JIA Xu REN Junguang XU Wentan MA Huchao ZHANG Chao SHI Guoming |
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| Institution: | School of Earth Sciences, Chengdu University of Technology, Chengdu 610059, Sichuan, China;School of Earth Sciences, Institute of Disaster Prevention, Sanhe 065201, Hebei, China;Longshou Mine, Jinchuan Group CO., LTD., Jinchang 737100, Gansu, China;School of Geoscience and Technology, Southwest Petroleum University, Chengdu 610500, Sichuan, China; Heilongjiang Geological Survey and Research Institute, Haerbin 150036, Heilongjiang, China |
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| Abstract: | This paper is the result of geological survey engineering.Objective] The Duobaoshan area of the Greater Xing''an Mountains is located on the tectonic belt between the Xing''an block and the Songnen block in the east of the Xingmeng orogenic belt. In this paper, the chronology and petrogeochemistry of the Late Paleozoic alkali feldspar granites in the Duobaoshan area are used to constrain the time limit of the collision between the Xing''an block and the Songnen block.Methods]In this paper, the zircon U-Pb geochronology and the whole rock geochemistry were carried out.Results] The LA-ICPMS U-Pb ages of zircons from two alkali-feldspar granite samples were (300.3±2.0) Ma and (307.3 ±1.7) Ma, respectively. Two samples have the similar geochemistry characteristics, with high silicon (SiO2=69.70% to 77.42%), relatively high aluminum (Al2O3=11.60% to 15.05%), and high alkali (K2O + Na2O=7.22% to 9.80%), low Ca and Mg (CaO=0.02% to 0.8%, MgO=0.02% to 0.48%), enrichment of Rb, Th, Zr and Hf, depleted of Ba, Sr, Nb and Ta, relatively high (Zr+ Nb + Ce + Y). In addition, they also have significantly negative Eu anomalies, with the right-leaningdistribution of rare earth elements and high zircon saturation temperature, suggesting both of them are A-type granites.Conclusions]Combined with the regionally tectonical evolution, it is concluded that the alkali-feldspar granite formed at extensional geological background of postcollision regime, marking the end of the collision between the Xing''an block and the Songnen block.Highlights: Determine the type of late Paleozoic alkali-feldspar granite in Duobaoshan area;Constrains the collision and assembly time of Xing''an and Songnen blocks. |
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| Keywords: | Late Paleozoic alkali-feldspar granite geochronology geochemical characteristics tectonic environment geological exploration engineering Duobaoshan area Daxinganling Mountains |
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