西乌珠穆沁旗巴彦呼舒花岗闪长岩锆石U-Pb LA-ICP-MS年龄、地球化学、Hf同位素特征及其地质意义  

Zircon U-Pb LA-ICP-MS Dating,Geochemical,Hf Isotopic Characteristics of Bayanhushu Granodiorite in West Ujimqin Banner and Geological Significance

作　　者：熊光强[1,2] 刘敏[1] 赵洪涛[1] 张达[1] 王浩然[1] 王忠 胡兆初[4] 

机构地区：[1]中国地质大学地球科学与资源学院,北京100083 [2]江西省地质矿产局物化探大队,南昌330002 [3]内蒙古地质调查院,呼和浩特010020 [4]中国地质大学地质过程与矿产资源国家重点实验室,武汉430074

出　　处：《地质论评》2015年第3期651-663,共13页Geological Review

基　　金：中国地质地质调查局项目中蒙边境东段深部结构及成矿条件对比研究(编号1212011085490);中国地质地质调查局项目内蒙古1:5万巴拉格尔农业分场幅;阿拉腾格勒公社幅;猴头庙幅;阿拉腾敖包大队幅区域地质调查(编号1212011120700)

摘　　要：本文报道的花岗闪长岩位于内蒙古巴彦呼舒以东10 km处。大地构造位于中亚造山带中段的锡林浩特晚古生代褶皱带。LA-ICP-MS锆石U-Pb测年获得该岩体的侵位年龄为236.1±3.4Ma。花岗闪长岩SiO2为66.93%～67.22%,Al2O3为15.13%～15.53%,K2O为2.47%～2.56%,Na2O为4.35%～4.46%,A/CNK值为0.94～0.95,显示该地区花岗闪长岩属于偏铝质钙碱性岩;亏损高场强元素,Sr达416.6×10^-6～425.7×10^-6,Sr/Y值为42～49,显示出高Sr低Y的典型特征,具有Adakite（高锶低钇中酸性岩）或者高Sr花岗岩的特点。花岗闪长岩的锆石εHf（t）值介于13.3～15.7之间;两阶段模式年龄分别为249～356Ma和258～422Ma。综合分析表明,花岗闪长岩为西伯利亚板块和华北板块碰撞闭合后,加厚的下地壳部分熔融作用的产物。The granodiorite of the article reports located in 10 km east of Bayanhushu Inner Mongolia. The tectonic position belongs to Late Paleozoic fold belt of Xilinhaote of the middle in central Asian orogenic. The age of this pluton is 236. 1 3. 4Ma by using LA-ICP-MS U-Pb zircon dating method. In this granodiorite,the content of SiO2 is 66. 93% ～ 67. 22%,Al2O3 is 15. 13% ～ 15. 53%,K2 O is 2. 47% ～ 2. 56%,Na2O is 4. 35% ～ 4. 46%,and the A / CNK is 0. 94 ～ 0. 95,this petrochemistry data indicate that the granodiorite belongs to the Partial aluminum and calc—alkaline series,and depleted in high field strength elements,the content of Sr is（ 416. 6 ～425. 7） 10- 6,Sr/Y is 42 ～ 49,this geochemical characteristic is the same as high Sr low Y of the adakite or high Sr granite. The εHf（ t） values and two staged Hf model age of the granodiorite is 13. 3 ～ 15. 7,249 ～ 356 Ma and 258 ～ 422 Ma. Synthetical analyze shows,The granodiorite is the product of the thickening of partial melting of crust after closed by Siberian plate and North China plate.

关 键 词：巴彦呼舒 锆石U-PB定年 Hf同位素特征 花岗闪长岩 西伯利亚板块 华北板块 

分 类 号：P588.12[天文地球—岩石学] P597.3[天文地球—地质学]