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东太平洋海山玄武岩属于大洋岛屿拉斑玄武岩，主要由橄榄拉斑玄武岩、石英拉斑玄武岩和橄榄玄武岩组成，具有拉斑玄武岩系列和过渡玄武岩系列。岩石具有基质为拉斑玄武结构或间隐结构的斑状结构和气孔构造，斑晶主要由拉长石和普通辉石组成，基质除拉长石和玻璃质外，还有少量普通辉石和磁铁矿等，岩石化学成分中Ａｌ２Ｏ３、Ｎａ２Ｏ、Ｋ２Ｏ含量偏高。玄武岩中稀土元素分配型式基本相同，曲线较平坦，稀土分馏不明显，具Ｃｅ、Ｅｕ负异常，反映岩石具有共同的成因，属晚白垩世以来的产物
The East Pacific seamounts basalt belongs to the oceanic island tholei basalt, mainly composed of olive tholei basalt, quartz tholei basalt and olivine basalts, with tholei basalt series and transitional basalt series. The rocks have the macular or stomatal structure of basaltic or interlaid basalts. The phenocrysts are mainly composed of labradorite and pyrrhyxite. In addition to labradorite and vitreous, there are a few of pyroxene and magnetite in the matrix , The rock chemical composition of Al2O3, Na2O, K2O content is high. The patterns of distribution of rare earth elements in basalt are basically the same, the curves are flat, the fractionation of rare earth is not obvious, with the negative anomaly of Ce and Eu, which reflects the common genesis of the rocks, which is the product of Late Cretaceous