地质与资源2023，Vol.32Issue(6)：655-663,9.DOI:10.13686/j.cnki.dzyzy.2023.06.001
大兴安岭甘南地区花岗岩LA-ICP-MS锆石U-Pb年龄、地球化学特征及其地质意义
LA-ICP-MS ZIRCON U-Pb DATING AND GEOCHEMISTRY OF THE GRANITES IN GANNAN AREA,DAXINGANLING MOUNTAINS:Geological Implication
摘要
Abstract
The formation age and petrogenesis of the two-mica monzogranite drilled from HGD-1 well in Gannan area of central-northern Daxinganling Mountains are determined and the regional tectonic setting is revealed on the basis of LA-ICP-MS zircon U-Pb chronology and petrogeochemistry studies.The zircons in granite are subidiomorphic-idiomorphic,with obvious oscillatory growth zone.The dating results show that the two-mica monzogranite was formed at 161 Ma,which is the product of magmatic event in early Late Jurassic.Geochemical analysis results indicate that the granite is characterized by high Si(SiO2 69.81％-74.3％),rich Al(Al2O3 13.5％-16.8％),and poor Fe(Fe2O3 0.26％-0.6％),belonging to quasi aluminous-weak peraluminous series in terms of chemical composition,with enriched LILEs(Rb,Ba and K)and HFSE(Hf),and depleted HFSEs(Nb,Ta and Ti),and relatively enriched LREEs and depleted HREEs,which is of Ⅰ-type granite.The magma originates from the partial melting of newly thickened continental crust material.The study results reveal that the formation of the early Late Jurassic two-mica monzogranite is related to the continent-continent collision environment during the closure progress of Mongol-Okhotsk suture zone,and its formation age restricts the closing time of Mongol-Okhotsk Ocean to the early Late Jurassic in Gannan area of central-northern Daxinganling Mountains.关键词
晚侏罗世/二云二长花岗岩/锆石U-Pb年龄/地球化学特征/蒙古-鄂霍次克洋/大兴安岭Key words
Late Jurassic/two-mica monzogranite/zircon U-Pb age/geochemistry/Mongol-Okhotsk Ocean/Daxinganling Mountains分类
天文与地球科学引用本文复制引用
李晓海,张海华,李文博,丁秋红,张健,陈树旺..大兴安岭甘南地区花岗岩LA-ICP-MS锆石U-Pb年龄、地球化学特征及其地质意义[J].地质与资源,2023,32(6):655-663,9.基金项目
中国地质调查局项目"松辽盆地北部及外围石炭-二叠系油气地质调查"(DD20190097) （DD20190097）
"东北地区重要盆地多能源资源地质调查"(DD20221664). （DD20221664）
