铜陵凤凰山矿田成矿构造应力场模拟研究

MODELING OF STRESS FIELD OF FENGHUANGSHAN OREFIELD DURING MINERALIZATION

本文分析了凤凰山矿田构造复合时序，厘定出Ｄ４及Ｄ５两期构造变形作用为主要的成岩成矿构造，确定了区内成矿构造应力场的最大剪应力方向为ＮＮＥ向。在此基础上，建立数值模型，进行同成矿构造应力场的数学模拟。初步得出，矿田内岩体接触带边缘及两侧的韧性剪切带为应力、应变及变形能的异常密集处，在多组构造复合处应力得以调整形成应力低，有利成矿部位必须对应剪应力变化梯度较大处，在此基础上，进行了成矿预测。

This paper analyses the characteristics of structural compounding of Fenghuangshan orefield,and brings to light that the deformations during D 4 and D 5 phases are main structures controlling mineralization.The information obtained by analysis of the compounding of structural systems together with the data of regional geology and geophysics indicates that NNE trending sinistral ductile shear zones which lie on the east and west sides of the pluton may provide the main dynamic source for structural control of mineralization.From the above,the synmineralization stress field of Fenghuangshan orefield is modeled by means of finite element method.The results indicate that anomalously concentrated stress and strain are located along the contrat zone between the pluton and country rock and the outer ductile shear zones.Low stresses occur where different systems of structures meet.Such places are favorable for the formation of deposits.