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新疆北部科克森套地区玄武岩出露于超镁铁质岩体的北侧,与玄武质凝灰岩共生,厚度达50～80 m;玄武岩普遍具有片理化、斑状结构;岩石地球化学特征表明,该玄武岩属低碱(Na2O+K2O均<3%,σ值在0.60～1.19)、低钛(TiO2在0.73%～1.22%)、富镁(MgO在7.43%～9.72%)的拉斑玄武岩系列,具有原始岩浆特征(其Mg#值在0.65～0.71),稀土总量较低(ΣREE在29.68×10-6～44.91×10-6),稀土及微量元素配分曲线平缓,可能形成于洋中脊构造环境。该区玄武岩的发现和岩石地球化学研究,佐证了科克森套蛇绿岩套的存在。
The basalt in the Kekesentao area of northern Xinjiang is exposed to the north side of the ultramafic rock mass and is intergrowth with basaltic tuff, and has a thickness of 50-80 m. The basalts generally have patchy and porphyritic structures. The geochemical characteristics of the rock show that the basalts Basalt belongs to the series of tholeiite basalt with low alkali content (Na2O + K2O <3% and σ value 0.60-1.19), low titanium (0.73% ~ 1.22% TiO2) and magnesium (MgO 7.43% ~ 9.72% With the original magmatic characteristics (Mg # value 0.65 ~ 0.71), the total rare earth content (ΣREE 29.68 × 10-6 ~ 44.91 × 10-6), rare earth and trace elements distribution curve is gentle, may form in the mid-ocean ridge structure surroundings. The discovery of basalt in this area and the study of geochemistry of rocks have corroborated the existence of the cochlear ophiolite suite.