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董家河蛇绿岩位于碧口群火山岩系西段,由蛇纹石化、滑石菱镁岩化变质橄榄岩、辉长岩、堆晶辉长岩和浅变质亚碱性拉斑玄武岩组成,具有典型的蛇绿岩套岩石组合特征.变质橄榄岩为轻稀土亏损型,辉长岩与变质玄武岩具共源岩浆演化特征,均表现为MORB型玄武岩的稀土元素及不活动痕量元素地球化学特征,是本区蛇绿岩的重要组成端元,指示扬子北缘碧口地区一个已经消失的古洋盆.辉长岩中锆石的激光探针U-Pb测年结果((839.2±8.2)Ma)表明,该洋盆形成于新元古代晋宁期.
Dongjiahe ophiolite is located in the west of Bikou Group volcanic rock series and is composed of serpentinization, talc magnesite metamorphism peridotite, gabbro, pluton-bearing gabbros and super-metamorphic sub-alkaline tholeiite, with typical The ophiolite assemblages are metamorphic peridotites, which are characterized by light rare earth depletion type, gabbro and metamorphic basalts with common source magmatic evolution, which are characterized by the REE and inactive trace elements geochemical characteristics of MORB basalts An important member of the ophiolite in this area indicates a disappearing paleo-ocean basin in the Bikou area on the northern margin of the Yangtze.U-Pb dating of zircons in gabbro ((839.2 ± 8.2) Ma) Show that the ocean basin formed in the Neolithic Jinning period.