滇中易门狮子山铜矿床构造控矿规律

Structural Control of Copper Mineralization at the Shizishan Deposit in Yimen,Central Yunnan

易门狮子山铜矿床是元古宙昆阳裂谷中的典型"东川式"铜矿床,具有层构双控、构造改造明显、多种矿体类型共存的特点。应用矿田地质力学的理论和方法,系统鉴定了主要断裂结构面力学性质,认为矿床受一系列轴向北东向的紧闭倒转复合倾伏褶皱和北东向压扭性断裂的控制,进一步总结了构造控矿特征;经构造筛分,厘定了构造体系,提出北东向构造带是主要控矿体系,该体系的主演化期为晋宁期-澄江期,叠加了印支期的变形,晋宁期-澄江期的改造作用使围岩中铜质活化、转移、富集成矿;概括出"层楼式"、"背斜+断裂"、"多字型"构造控矿型式,为深部隐伏矿定位预测提供了依据。

The Shizishan copper deposit in Yimen is one of the typical ＂Dongchuan -pattem＂ copper deposit formed in the Kunyang rift of Proterozoic age. It has the characteristics of being controlled by both stratum and structure, obvious structural rework and coexistence of different types of orebodies. The theory and method of ore field geomechanics were used to appraise the mechanical property of main structure plane systematically, It is believed that the mineralization is jointly controlled by a series of northeast striking, closed, inverted and composite plunging folds and compresso - shear faults. The characteristics of structural control on copper mineralization has been summarized in detail. After sieving the structure and determining the stucture system, it is concluded that the northeast striking structure zones are the main ore - controlling system, whose main evolution phase was Jinning - Chenjiang period （Proterozoie）, superimposed with the deformation of Indosinian period （Triassic）. The reworking of Jinning - Chenjiang period made the copper in wall rocks being activated,transferred and enriched to form mineralizion. ; Three ore - controlling structure patterns such as ＂storey＂, ＂anticline ＋ fault＂ and ＂ξ＂ are summed up to provide mineralization prognosis model for exploring concealed ores.