贵州晴隆锑矿茅口组顶岩溶面形态特征及控矿作用

Morphological characteristics and ore-controlling role of palaeo-karst surface of Maokou formation in Qinglong Sb Deposit,Guizhou Province

贵州晴隆锑矿主要产自上二叠统峨眉山玄武岩第一旋回——"大厂层",与下伏茅口组灰岩呈岩溶不整合接触。应用钻孔数据通过3DSufer软件,建立古岩溶不整合面和大厂层厚度分布立体模型,结合矿体及断裂的分布情况,分析古岩溶不整合面形态、大厂层厚度分布特征以及两者对成矿的作用,结果表明:茅口组灰岩顶部古岩溶不整合面是一个以三望坪矿段为中心的北东走向隆起,周围分布有岩溶斜坡和洼地。大厂层厚度变化较大,古岩溶不整合面对大厂层整体厚度变化无直接影响,在局部地区出现"印模"现象。矿源的丰富与否取决于大厂层沉积厚度,但矿源最终富集成矿体,还受到断裂构造、容矿空间以及流体改造程度的控制。

; Qinglong Sb Deposit mainly occurred in the first cycle of Upper Permian Emeishan basalt which is named Dachang Strata. Dachang Strata has a karst unconformable contact with underlying limestone of Maokou Formation. The 3D model of palaeokarst unconformity surface and thickness-distribution of Dachang Strata is established by using drilling data through 3D sufer software. The analysis results of their characteristics and ore-controlling role are obtained by combining of the distribution of ore bodies and faults. Palaeokarst unconformity surface on top of Maokou Formation limestone appears a NE-trending uplift, which is centered with the Sanwangping Ore Sec- tion arounded by karst slopes and karst depressions. Thickness of Dachang Strata varies greatly. Palaeokarst uncon- formity surfaces have no influence on the thickness of Dachang Strata. There are some impressions locally. How rich the ore source is depends on the thickness of Dachang strata. Besides, ore-forming processes are controlled chiefly by faults, host space and liquid reformation.