四川红泥坡铜矿床三维地质建模及控矿构造演化的新认识

红泥坡铜矿是近年来在四川拉拉地区发现的一个大型铜矿床,其包含铜储量64.2万t,平均品位1.31%。矿体赋存于元古宙老的褶皱基底河口群,与辉长岩侵入体具有时间上的联系,围岩发生了普遍的钠质蚀变。通过红泥坡铜矿区224个钻孔和23条勘探剖面建立了矿体、地层与构造要素的三维模型,该三维地质模型能够表达矿床的精细地质结构以及解释区域成矿作用与构造演化:矿区早期的南北向主应力使河口群形成轴向近东西向的大型向斜,晚期的东西向主应力在改造早期褶皱基底的基础上,形成了叠加在其之上的轴向北北东向的复向斜。经过两期主要的构造运动,该地区形成了现在北北东向与北西西向构造相叠加的格架。本项研究为拉拉地区的矿床学研究提供了新的思路,并能对该地区矿产勘查提供科学依据。

3D Geological Modeling and New Understanding of Ore-controlling Tectonic Evolution of the Hongnipo Copper Deposit in Sichuan Province

The Hongnipo copper deposit is a newly discovered large copper deposit in the Lala region of Sichuan Province, which contains reserves of 642,000 tons Cu with an average grade of 1.31%. Ore bodies are hosted in the Proterozoic fold basement Hekou Group and they have a temporal association with gabbro intrusions, the host rocks have a generally sodic alteration. In this paper, a three-dimensional model of ore bodies and strata is constructed using 224 boreholes and 23 cross sections in the study area. The 3D geological model can delineate fine geological structure of the deposit and explain the regional metallogenesis and tectonic evolution: the early N-S principal stress in the mining area caused the Hekou Group to form a large syncline near E-W direction. On the basis of the reconstruction of the early fold basement, an axial NNE synclinorium superposed on it was formed under the late E-W principal stress. After two-stage major tectonic movements, the area has formed an overlay frame of NNE-SSW and NWW-SEE structures. This study provides new ideas for the research of mineral deposits in the Lala region, and can provide scientific guidance for mineral exploration in the region.