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崇根山岩块是贺根山蛇绿岩带内超基性岩出露面积最大的岩块,岩性主要以二辉橄榄岩为主,方辉橄榄岩次之以及少量纯橄岩透镜体或团块。岩石学和地球化学特征表明这套超基性岩属于位于蛇绿岩套中下部的地幔橄榄岩序列,其二辉橄榄岩和方辉橄榄岩具有富Al的特征,分异指数很低(DI=0.1~2.79),而固结指数很高(SI=79.9~89.62),代表了原始地幔的残余。稀土元素表现为LREE弱亏损的特征,与阿尔卑斯型辉橄岩相似;纯橄岩稀土含量仅为球粒陨石的1/10,具有“U”型稀土元素分布模式,与阿尔卑斯橄榄岩和SSZ型蛇绿岩地幔橄榄岩相似。崇根山大面积出露的二辉橄榄岩可能代表了洋盆扩张早期的地幔橄榄岩的残余。整体上富Sr贫Ti的现象暗示了后期消减作用对地幔橄榄岩地球化学结构的影响。
Chongganshan block is the rock mass with the largest exposed area of Hegenang ophiolite zone. The lithology is mainly composed of lherzolites, followed by hectorite and a small amount of dunite lenses or clumps . Petrological and geochemical characteristics indicate that the ultrabasic rocks belong to the sequence of mantle peridotites located in the lower part of the ophiolite suite. The lherzolites and harzburgites are Al-rich and have very low index of divergence (DI = 0.1-2.79), while the consolidation index is very high (SI = 79.9-89.62), representing the remnants of the original mantle. Rare earth elements are characterized by weak depletion of LREE, which is similar to that of alpine dolomite. The content of rare earths is only 1/10 of that of chondrules, and has the pattern of “U” REE, which is similar to the Alpine peridotite SSZ ophiolite mantle peridotite similar. The extensive exposure of the lofts in Chongngshan may represent the remnants of the mantle peridotite in the early period of oceanic expansion. As a whole, the phenomenon of depletion of Sr-rich Ti implies the effect of post-depletion on the geochemical structure of the mantle peridotite.