龙山金锑矿区矿体侧伏规律及其控制因素

The Ore-controlling Factors and Regularity for Lateral Trending of Orebodies in Longshan Au-Sb deposit

龙山金锑矿床处于华南板块之江南地块南东,往南与南华活动带相邻,区域构造兼具隆起带和活动带的特点。白马山—龙山EW向构造隆起带控制了区域钨锑金矿带的展布,龙山穹窿控制了龙山金锑矿床的就位。龙山地区经历了四次主要构造运动,雪峰运动形成EW向龙山穹窿雏形,加里东运动形成NE向复式褶皱,印支运动主要表现为NNE向劈理(硅质条带充填)叠加,燕山运动以NNE向断裂为主要特色,经历了由塑性到脆性、由褶皱为主到断裂为主的形变过程。龙山倒转复式背斜控制了龙山金锑矿床的就位及矿脉(体)的展布,核部发育的多组断裂控制了矿体的就位,其中与区域劈理大角度相交的NWW组断裂为主要容矿构造,与NNE、NE向断裂及密集的轴面劈理相交部位成矿有利,沿其交线附近往往有板柱状矿体分布,矿体倾向延深大于走向长,一般延深为走向长的1～5倍,并明显向北西侧伏,与褶皱轴面倾向大体一致。

Longshan Au-Sb deposit is located in the southeast of Jiangnanblocks, and reaches south to South China fold belt, which is in the Yangzi plate. The feature of the regional structureinclude the feature of uplift belt and Fold system, has both Jiangnanblocks and South China fold belt. The W-Sb-Au ore belt in the regional is controlled by the Baimashan-Longshanuplift belt, and the Longshan Au-Sb deposit is controlled by Longshan dome. There're 4 times tectonic movements in Longshan area. In the Xuefeng movement, the NWW strike Longshan dome was taking embryonic form. In the Caledonian movement,the NE strike comprehensive fold was formed. In the Indosinian movement, the NEE strike cleavages superimposed on the earlier folds. In the Yanshan movement, the NEE strike faults deformation went from plastic to brittle, and the structurepredominantly fold become fault. The location of Longshan Au-Sb deposit and the distribution of ore veins(bodies) are controlled by Longshan overturned multiple anticline.Multiple sets of fractures in anticlinenucleuscontrollthe places of ore-bodies. NWW trending faults, which intersecting with large-angle with regional cleavages are main ore structures. Intersectantposition of NNE and NE trending faults and intensiveaxial plane cleavages, are mineralization favorableness. Slab-column ore bodies distribut along near intersecting lines of them. The dipping length of the orebodies is larger than the striking length. The dipping length of the orebodies is often 1 to 5 times of the striking length.The orebodiesare obvious lateral trending along NW trending In accordance withaxial plane dipping of folds.