内蒙古海拉尔北部八大关地区花岗岩的成岩时代、地球化学特征与成因
发布时间：2019-01-03 21:48
【摘要】：内蒙古海拉尔北部八大关地区花岗岩以正长花岗岩和二长花岗岩为主,锆石U-Pb定年显示其形成于晚三叠世((212±1.7)~(226.7±1.6)Ma)。岩石为弱过铝质(A/CNK=1.01~1.10),分异指数(DI)介于92.5~95.8之间。岩石大离子亲石元素K和Rb以及LREE相对富集,高场强元素Nb、Ta、P、Ti和Ba、Sr相对亏损,并显示中等铕负异常(δEu=0.51~0.71)。较低的10 000 Ga/Al值(平均1.91)以及较低的锆石饱和温度(平均683℃)等特征显示该花岗岩属于高分异Ⅰ型。锆石的εHf(t)值较高(4.50~10.45),Hf二阶段模式年龄为0.59~0.97 Ga,反映其源区物质为新元古代增生的基性地壳。综合区域其他地质研究成果,认为研究区晚三叠世花岗岩形成于蒙古—鄂霍茨克洋板块俯冲的活动大陆边缘环境。
[Abstract]:The granites in Badaguan area, northern Hailaer, Inner Mongolia are dominated by syenite and monzomorphic granites. Zircon U-Pb dating indicates that they were formed in the late Triassic (212 卤1.7) ~ (226.7 卤1.6) Ma). The rock is weak peraluminous (A/CNK=1.01~1.10) and its differentiation index (DI) is between 92.5 and 95.8. Large ion lithophile elements K, Rb and LREE are relatively enriched, and high field strength elements Nb,Ta,P,Ti and Ba,Sr are relatively depleted, showing moderate europium negative anomaly (未 Eu=0.51~0.71). The lower Ga/Al value of 10 000 (average 1. 91) and the lower zircon saturation temperature (mean 6 83 鈩，
本文编号：2399911
[Abstract]:The granites in Badaguan area, northern Hailaer, Inner Mongolia are dominated by syenite and monzomorphic granites. Zircon U-Pb dating indicates that they were formed in the late Triassic (212 卤1.7) ~ (226.7 卤1.6) Ma). The rock is weak peraluminous (A/CNK=1.01~1.10) and its differentiation index (DI) is between 92.5 and 95.8. Large ion lithophile elements K, Rb and LREE are relatively enriched, and high field strength elements Nb,Ta,P,Ti and Ba,Sr are relatively depleted, showing moderate europium negative anomaly (未 Eu=0.51~0.71). The lower Ga/Al value of 10 000 (average 1. 91) and the lower zircon saturation temperature (mean 6 83 鈩，
本文编号：2399911
本文链接：https://www.wllwen.com/kejilunwen/diqiudizhi/2399911.html
