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多彩蛇绿岩是通天河蛇绿混杂岩的组成部分,区域上隶属西金乌兰—金沙江缝合带北延部分。多彩蛇绿岩各岩石组分呈构造岩块、岩片产出,出露零星,面积小,但岩石组分较齐全,主要由异剥橄榄岩、单斜辉石岩、辉长岩、玄武岩、辉绿岩及硅质岩等组成,缺乏地幔橄榄岩,蛇绿岩组分均与围岩呈构造接触关系。异剥橄榄岩以富MgO、贫TiO2、贫P2O5为特征,Eu不显异常或显弱负异常,是具有SSZ型蛇绿岩的重要岩石组分;辉长岩具高TiO2、Al2O3;玄武岩与辉绿岩具相似的特性,玄武岩Th/Ta平均为1.78,Ta/Hf>0.15,而Ta/Hf=0.15～0.2,与大洋板内玄武岩相似;硅质岩Al2O3/(Al2O3+Fe2O3)比值为0.9,(La/Ce)N值为1.81,可能具有陆源海特性。由上述特征并结合蛇绿岩形成时代及构造环境判别图解,推测多彩蛇绿岩形成于俯冲带构造环境。
Colorful ophiolite is part of the Tongtanghe ophiolitic melange and belongs to the northern extension of the Xijinwulan-Jinshajiang suture in the area. The colorful ophiolite rock components are tectonic rocks, rock output, reveal sporadic, small area, but more complete rock composition, mainly by the de-peridotite, clinopyroxenite, gabbro, basalt, Diabase and siliceous rocks, lack of mantle peridotite, ophiolite components are structural contact with the surrounding rock relations. The dextral peridotites are characterized by rich MgO, lean TiO2 and poor P2O5, while Eu is not significant anomaly or weakly negative anomaly. It is an important rock component with SSZ-type ophiolite. The gabbro with high TiO2, Al2O3, basalt and The diabase is similar in character to the average Th / Ta basalts of 1.78 and Ta / Hf> 0.15, while Ta / Hf = 0.15-0.2, which is similar to basaltic rocks in the oceanic plate. The ratio of Al2O3 / (Al2O3 + Fe2O3) 0.9, (La / Ce) N value of 1.81, which may have terrigenous properties. Based on the above characteristics and combining with the discrimination of age and tectonic setting of ophiolite, it is presumed that colorful ophiolite formed in tectonic setting of subduction zone.