中文摘要：

大兴安岭北部早白垩世上库力组流纹岩具有富碱（w（K2O＋Na2O）〉6.10%）、高w（K2O）（3.25%～5.30%）、高K2O/Na2O（0.67～2.48）的特点,属于高钾钙碱性系列。强烈富集大离子亲石元素（LILE）和轻稀土元素（LREE）,明显亏损Ba、Sr、Nb、P、Ti,较高的Th质量分数和高的Rb/Ba、Rb/Sr和Zr/Ba表明,该流纹岩形成于大陆板内拉张构造环境,是蒙古-鄂霍茨克造山带形成后伸展作用的结果。现有资料表明,形成流纹岩的原生岩浆可能是下地壳部分熔融的产物。

英文摘要：

The rhyolites of the Early Cretaceous Shangkuli Formation in northern Daxing＇anling belong to high-K calc-alkaline volcanic rock series characterized by rich-alkaline（K2O＋Na2O6.10%）,high K2O（3.25%-5.30%） and high ratios of K2O/Na2O（0.67-2.48）.These samples show strong enrichment in large ion lithophile elements（LILE） and in light rare earth elements（LREE）.But the elements of Ba,Sr,Nb,P,and Ti are apparently depleted.The higher Th content and high Rb/Ba,Rb/Sr and Zr/Ba ratios of the rhyolites suggested a continental intraplate rifted setting related to the extension stage after the formation of Mongolia-Okhotsk orogenic belt.The current data indicate that the parental magma for rhyolites could be the products of the lower crust partial melting.