滇西北维西地区超镁铁岩—镁铁岩的岩石特征与成因  

Rock characteristics and genesis of ultramafic-mafic rocks in Weixi area,Northwest Yunnan

作　　者：胡凯兵 李杭 严城民[2] 顾光明 刘清华 李晨刚 HU Kaibing;LI Hang;YAN Chengmin;GU Guangming;LIU Qinghua;LI Chengang(Yunnan Nuclear Industry Geological Survey Institute,Kunming 650106,Yunnan,China;Regional Geology and Mineral Survey Team,Yunnan Bureau of Geology and Mineral Exploration,Yuxi 653100,Yunnan,China)

机构地区：[1]云南省核工业地质调查院,云南昆明650106 [2]云南省地矿局区域地质矿产调查大队,云南玉溪653100

出　　处：《矿产与地质》2023年第3期534-542,共9页Mineral Resources and Geology

基　　金：香格里拉市自然资源局勘查项目“云南省香格里拉休瓦促牛场钨钼矿详查”(2015—2017年度)资助。

摘　　要：在系统搜集前人资料的基础上,通过多次实地考察与资料整理,将滇西北维西地区的超镁铁岩-镁铁岩划分为5个岩带,分属4种成因类型,即:①白济汛构造蛇绿混杂岩的成因与科迪勒拉型蛇绿岩的岛弧较为相似,形成于澜沧江洋火山弧环境;②维登镁铁岩属沿澜沧江断裂侵入的镁铁岩,岩石成因与阿拉斯加型岩体相似;③雪龙山构造蛇绿混杂岩的成因与东地中海型蛇绿岩较为接近,形成于德钦—雪龙山洋盆环境;④工农构造蛇绿混杂岩的成因与科迪勒拉型蛇绿岩极为类似,是金沙江小洋盆俯冲消减过程中,攀天阁—崔依比弧间或弧后扩张的产物;⑤霞若构造蛇绿混杂岩的成因可能为西地中海型蛇绿岩,形成于被动大陆边缘张开的小洋盆环境。研究滇西北维西地区超镁铁—镁铁岩的岩石特征及成因,有助于进一步查明该地区古特提斯构造特征及其演化。Based on the systematic collection of previous data,through many field investigations and data collation,the ultramafic rock-mafic rock in the Weixi area of Northwest Yunnan is divided into five rock belts,belonging to four genetic types.They are listed as follows.(1)The genesis of Baijixun tectonic ophiolitic melange is similar to the island arc of Cordillera-type ophiolite,which is formed in Lancangjiang oceanic volcanic arc environment.(2)Weideng magnesium iron rock belongs to the magnesium iron rock which intrudes along the Lancang River fault,and the rock genesis is similar to Alaska rock mass.(3)The genesis of Xuelongshan tectonic ophiolitic melange is close to that of the eastern Mediterranean type,which is formed in the Deqin-Xuelongshan oceanic basin.(4)The genesis of Gongnong tectonic ophiolitic melange is very similar to that of the Cordillera type,which is the product of the Pantiange-Cuiyibi inter-arc or post-arc extension during the subduction of the Jinsha River oceanic basin.(5)The genesis of Xiaruo tectonic ophiolitic melange might be the west Mediterranean type,which is formed in the small oceanic basin environment of the passive continental margin.The study of rock characteristics and genesis of ultramafic-mafic rocks in the Weixi area of Northwest Yunnan is helpful to further clarify the tectonic characteristics and evolution of the Paleo-Tethys in this area.

关 键 词：超镁铁岩-镁铁岩 岩石特征 成因 滇西北维西地区 

分 类 号：P588.12[天文地球—岩石学]