塞国苏拉山–坎尕瑞山地区金铁矿特征与成矿远景

Characteristics and Metallogenic Prospects of the Sulashan Kangarushan Gold Ore Deposit in Sierra Leone

摘要: 本区是塞国出露面积最大的太古代绿岩带，南北长120 km，东西宽10 km，在此区域内各支流均有砂金矿床分布。在本区内坎尕瑞山南部宝马洪一带已提交大型原生金矿。该区域构造发育，岩石变质、变形强，虽然前人已进行大规模的砂金矿开采，并找到大型原生金矿。但是，从成矿带的规模分析仍具有很好的找矿前景，特别是苏拉山北部地区至今没有发现较好的原生金矿。研究区内金、铁矿的形成与绿岩带、花岗岩、韧性剪切带有一定的关系，金铁矿均受一定层位控制，金矿主要赋矿层位为太古宙Ls变质基性–超基性岩，铁矿主要的赋矿层位为太古宙Lt变质沉积岩；金矿与造山后期侵入岩有一定时空关系，且提供了热源条件；韧性剪切带为金的活化迁移提供了通道和富集空间；金矿矿化类型主要为中低温的构造蚀变岩型，其次为石英脉型，铁矿矿化类型为条带状磁铁石英岩(BIF)型。

Abstract: This area is the Archean greenstone belt with the largest exposed area in Serbia. It is 120 km long from north to south and 10 km wide from east to west. Gold placer deposits are distributed in all tributaries in this area. In this area, a large primary gold deposit has been submitted from the Baobahong 1 belt in the south of the Kanggarui Mountain. The regional structure is well developed, with strong rock metamorphism and deformation. Although the predecessors have carried out large-scale placer gold mining and found large primary gold deposits. However, based on the analysis of the scale of the metallogenic belt, there is still a good prospecting prospect, especially in the northern part of the Sula Mountains, no good primary gold deposits have been found so far. The formation of gold and iron ores in the study area is related to the greenstone belt, granite and ductile shear zone. Gold and iron ores are controlled by certain horizons. The main ore hosting horizon of gold ores is Archean Ls metamorphic basic ultrabasic rocks, and the main ore hosting horizon of iron ores is Archean Lt metamorphic sedimentary rocks; there is a certain space-time relationship between gold deposits and post orogenic intrusive rocks, which provides heat source conditions; the ductile shear zone provides the pathway and enrichment space for the activation and migration of gold; the gold mineralization type is mainly medium low temperature tectonic altered rock type, followed by quartz vein type, and the iron ore mineralization type is banded magnetite quartzite (BIF) type.