摘要
西乡群孙家河组火山岩形成于晚泥盆 早石炭世 ,组内火山熔岩主要为一套亚碱性玄武岩和安山岩 ,具有高Ba及显著的Nb、Ta亏损 ,其Th Yb、Ta Yb、Th Ta、Nb La和Ti Zr、Ti Y等不活动痕量元素组合指示其形成于大陆边缘弧 (活动陆缘 )环境。这套火山岩在区域上可能与勉略带相联 ,指示南秦岭泥盆
The Sunjiahe volcanic rocks of Xixiang group are composed of subalkaline basalt and andesite. Both of them exhibit the typical geochemical features of high content of Ba, remarkable depletion of Nb and Ta. In addition, the Th/Yb Ta/Yb and Ti/Zr Ti/Y ratios of the basalt indicate that the volcanic rocks in the studied area occurred in a typical tectonic setting of an island arc. It is proposed that the occurrence of the volcanic rocks might be related to subduction of an ancient oceanic crust represented by the Mianlue suture zone and developed during Carbono\|Devonian in south Qinling.
出处
《地质科学》
CAS
CSCD
北大核心
2001年第3期295-303,共9页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
国家自然科学基金秦岭重点项目(编号 :4 9732 0 80 )
中国科学院LNAT核分析技术联合开放实验室(编号 :97B0 0 6)
陕西省教委专项科研
