广西五圩铅锌锑多金属矿田成矿分带特征及找矿预测研究

发布时间：2018-05-12 13:06

  本文选题：矿田构造 + 流体包裹体　； 参考：《广西大学》2015年硕士论文

【摘要】：五圩矿田位于桂西北丹池成矿带南东段,是一个以铅、锌、锑、银、汞、砷等一套中低温元素成矿为主的多金属矿田,区内主要矿床(点)有箭猪坡铅锌锑多金属矿(大型)、三排洞铅锌锑多金属矿(中型)、塘志-坡平铅锌锑多金属矿(中型)、芙蓉厂铅锌锑矿(中型)、水落砷钼汞多金属矿(中型)、拔旺锑矿点和桥凳-九瓦汞矿点等。本文主要针对五圩矿田开展了矿田构造、矿物学特征、流体包裹体和矿床地球化学等的研究,在此基础上,总结了矿田的成矿分带特征,提出了今后找矿方向。取得的主要成果和认识有：(1)矿田内主要构造为NNW向五圩背斜和NNW向断裂。五圩背斜为一轴向NNW的复式短轴背斜,由两个次级背斜组成。背斜两翼不对称,东翼缓(20～50°)、西翼陡(60～85°),沿轴向呈“S型”拐弯,拐弯部位呈NW向。NNW向断裂为矿田内主要断裂构造,也是区内主要控矿构造。该组断裂经历了两期活动,早期以挤压为主兼具顺时针(右旋)扭动,晚期以张性为主兼具逆时针(左旋)扭动,由于早期断裂活动强烈,晚期构造活动仅在局部叠加,因此,断裂总体表现出压扭性特征。(2)通过对五圩矿田内主要矿床(点)的矿物学特征、流体包裹体、元素地球化学特征等研究,发现矿田内各矿床(点)的矿物粒径、矿物颜色、成矿温度和成矿元素特征比值等存在规律性变化,可划分为三个成矿带,即中低温成矿带(Ⅰ)、中温成矿带(Ⅱ)和中高温成矿带(Ⅲ)。由Ⅰ→Ⅱ→Ⅲ成矿带闪锌矿和辉锑矿的矿物粒径逐渐增大,闪锌矿颜色逐渐加深；成矿温度由低到高(145～249℃→220-265℃→245-322℃);(Hg+As)/(Zn+Pb)和(Hg+As)/Zn等特征比值均出现较明显递减,即低温矿物元素的富集呈递减趋势,而高温矿物元素富集则呈递增趋势。(3)依据成矿分带特征结合地球物理资料认为,矿田中部的箭猪坡矿区是五圩矿田的成矿中心和隐伏岩体可能的产出部位,箭猪坡矿床的深边部尤其是NNW向背斜的拐弯部位是成矿最有利地段和今后的找矿远景区。(4)由成矿期共轭节理所求得的交线产状和主成矿阶段断裂面上的擦痕、阶步所指示的运动方向推测,箭猪坡矿床成矿热液可能来自NE方向,脉状矿体向NE侧伏,由此认为箭猪坡矿床NE方向的深部是寻找脉状矿体有利部位。(5)本次调查在箭猪坡矿床310斜井壁(NNW向五圩背斜拐弯处)新发现有厚约7m的缓倾斜似层状Sn-Pb-Zn-Sb矿体,其与大厂锡矿的似层状矿体相类似,进一步证实了本研究认识的客观性。
[Abstract]:The Wuxu ore field is located in the eastern section of the Danchi metallogenic belt in northwest Guangxi. It is a polymetallic ore field dominated by lead, zinc, antimony, silver, mercury, arsenic and so on. The main deposits (points) in this area are Qianzhoupo lead-zinc antimony polymetallic ore (large scale, Sanpaitong Pb-Zn antimony polymetallic ore) (medium-sized, Tangzhi-Puping lead-zinc antimony polymetallic ore) (medium scale, Furongchang lead, zinc and antimony ore, medium size, water arsenic and molybdenum mercury ore). Polymetallic ores (medium-sized, Bawang antimony and Qiaoben- Nine Watt mercury ore sites, etc. Based on the study of the structure, mineralogical characteristics, fluid inclusions and deposit geochemistry of the Wuwei ore field, this paper summarizes the ore-forming zonation characteristics of the ore field and puts forward the prospecting direction in the future. The main structures in the ore field are NNW anticline and NNW fault. Wuxu anticline is a compound short axis anticline with an axial NNW, which is composed of two secondary anticlines. The two wings of the anticline are asymmetrical, the east wing is 20 ~ (50) 掳/ m, and the west wing is 60 ~ 85 掳/ m. Along the axis of the anticline is a "S" bend, and the bend is NW. NNW trending fault is the main fault structure in the ore field and is also the main ore-controlling structure in the area. This group of faults experienced two stages of activity. In the early stage, the compression was mainly accompanied by clockwise (dextral) twisting, and in the late stage it was mainly tensional and counterclockwise (left-handed). Due to the strong early fault activity, the late tectonic activity was only superimposed locally, so, By studying the mineralogical characteristics, fluid inclusions and element geochemistry of the main deposits (points) in Wuwei ore field, it is found that the mineral particle size and mineral color of each ore deposit (spot) in the ore field. There are regular changes in metallogenic temperature and metallogenic element characteristic ratio, which can be divided into three metallogenic belts, I. e. Middle and low temperature metallogenic belts (鈪，

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