大兴安岭古里林场甘河组火山岩地球化学特征及构造背景

Characteristics of the Ganhe Formation Volcanic Rock Geochemistry and Tectonic Setting in the Guli Area of the Greater Khingan Range

大兴安岭古里林场地区甘河组玄武质岩石为一套碱性系列岩石,稀土元素表现为轻稀土富集、重稀土相对亏损的特点,弱σEu负异常,P相对富集,Rb、Th、Nb、Ta贫化,Ti弱亏损,表明甘河期火山岩可能来源于上地幔,并受地壳的混染。综合研究表明,研究区内火山岩形成于板内环境。

The basaltic rocks of the Ganhe Formation belong to alkaline series in the Guli Area of the Greater Khingan Range.REE are characterized by LREE enrichment and HREE depletions,has weak negative Eu anomalies.The trace elements are characterized by Penrichment and Rb,Th,Nb,Ta,Ti depletions.These characteristics suggest that the magma of the Ganhe Formation may be derived from the upper mantle,and the magma was contaminated by the upper crustal materials.The comprehensive research presents that the volcanic rocks of the Ganhe Formation in study area was fromed in the continental plate environment.