莫托萨拉铁锰矿硅质岩呈层状产于铁矿中 ,含热水沉积矿物。岩石的 Fe2 O3,Au,Ag,Cu,Pb,Zn,As,Sb,Hg质量分数高 ,Cr,Ni,Co,Fe O,Al2 O3质量分数低 ,w( Al) /w( Al+Mn+Fe)比值低 ,这些元素组合指示出其热水沉积成因。在判别硅质岩形成作用的主元素和微量元素关系图上 ,硅质岩主要位于热水沉积作用的范围内或接近于热水沉积作用。岩石的稀土元素和 O,Si同位素组成表明硅质岩是由热水沉积作用形成的。 Motosala ferromanganese siliceous rocks are layered in iron ore, with hydrothermal sedimentary minerals. The mass fraction of Fe2O3, Au, Ag, Cu, Pb, Zn, As, Sb and Hg in rock is high and the mass fraction of Cr, Ni, Co, FeO and Al2 O3 is low, Fe) ratio is low, the combination of these elements indicates the cause of its hot water deposition. On the relationship between major elements and trace elements that discriminate the formation of silicalite, the chert is mainly located in the range of hydrothermal sedimentation or close to hydrothermal sedimentation. Rare earth elements and O, Si isotopic compositions of rocks indicate that chert is formed by hydrothermal sedimentation.