微量元素和稀土元素的断裂构造地球化学研究

STUDY ON FAULT TECTONOGEOCHEMISTRY OF TRACE ELEMENT AND REE

本文通过对水口山矿区断裂构造的系统采样和元素含量分析。探讨了断裂作用对微量元素和稀土元素的影响。断裂作用可使微量元素产生显著分异,元素在断裂带中的聚散性可划分为三个系列:聚集系列。分散系列和变化系列。元素的聚散性与元素本身性质和断裂力学性质(剪应力强度)有关,其聚集系数与元素电负性(χ)和剪应力(τ)成正比,与元素的原子半径(γ)和标准状态熵值(S_(298)~0成反比。电负性大、原子半径小。标准状态熵值低的Cu、Pb、Zn、Au、Ag、Mn等元素在压剪断裂带中显著聚集。断裂作用不仅使REE发生整体迁移而使断裂带中∑REE含量显著降低,还使REE发生分异作用。特别是HREE与LREE的分异,具变化合价的Ce、Eu等元素的分异。图3,表3,参9。

Based on systematically sampoing and analyses of element contents of fracture in the shuikoushan mine area, this paper discusses affect of faulting on trace element and REE. Faulting had differentated strongly trace element, concentration-dispersion properties of element in fracture zone are divided three series:concentrative series, disperaiveseries and changeful series:concentration-dispersion properties is relative to element itself nature and mechanical properties of fracture (intensity of shear stress) concentration coefficient is directly proportional to electronegativities (x) and shear stress(τ), and is inverse proportional to atomic radius (r) and entropy of standard state (S_(298)~0) . Cu, Pb, Zn, Au、 Ag、 Me、 etc., which have bigger electronegativities and small atomicradius and lower entropies, concentrate enormously in ccmpresso-shear fracture zone.Fault tectonism not only had brought about the REE whole-migration and ΣEEE in fracture zone had reduced enormously, but also REE differentiation, particularly differentiation of HREE and LREE and Ce, Eu etc. which have changeable valence.3figs., 3tabs., 9refs.