摘要
西成矿田位于昆仑—秦岭褶皱区、西秦岭海西—印支地槽褶皱带西部。甘肃省徽县某大型铅锌矿床位于西成矿田东部,为位于西秦岭多金属成矿带西成矿田内具有代表性的矿床之一。为进一步指导矿区深部及外围找矿预测工作,结合该区已取得的地质工作成果,详细分析了区域成矿地质背景、矿床地质特征,从成矿物质(成矿元素和成矿流体)、能量、介质、通道(导矿构造)、空间(容矿空间)等方面,深入讨论了矿区地层、构造、岩浆与成矿的关系,并进一步研究了矿床成矿模式。研究表明:(1)矿区出露的地层主要为中泥盆统安家岔组焦沟层(D_2a^2)及第三系(T),其中,中泥盆统安家岔组焦沟层上层(D_2a^(2-2))为富矿层位;(2)矿床整体受地层、构造控制明显,矿床整体产状、规模及厚度变化较大,沿倾向、走向形态复杂多变,具有膨大窄缩、尖灭再现的特点,多呈囊状、透镜状产出;(3)矿区矿床主要受控于中泥盆统安家岔组焦沟层(D_2a^2)及层间破碎带、人土山—两当断裂及黄渚关深大断裂、印支期糜署岭花岗闪长岩及岩浆热液;(4)通过对比西成矿田内各铅锌矿床的地质特征,明确了徽县某铅锌矿床成因,认为其成因类型为热水沉积改造型铅锌矿床;(5)矿区有利的找矿标志为含矿地层及其岩性组合特征、地表出露的呈黄褐色的铁碳酸盐化千枚岩层、人土山—江洛大断裂北侧、地表出露的赋矿地层(碳酸盐岩地层)等。在上述分析的基础上,进一步研究认为:(1)矿区深部隐伏矿床的有效控制方式为钻孔或坑道;(2)矿床东西部地区找矿前景较好,矿床北部勘探程度较低,宜增加勘探工程量;(3)在矿床外围找矿过程中,矿床西部地区可适当增加工程控制深度,东部地区可适当减少工程控制深度;(4)矿区盲矿体找矿潜力较大,可首先综合运用物化探方法圈定异常,然后进行地表查证及坑钻探验证,有望取得理想的找矿预测效果。
Xicheng Ore-field is located in Kunlun-Qinling fold area and the western part of West Qinling Haixi-Indo-Chinese Epoch geosynclinal gold belt. The Pb-Zn deposit in Huixian County,Gansu Province is located in the eastern part of Xicheng Ore-field,it is one of the representative deposits in Xicheng Ore-field in Xiqinling polymetallic metallogenic belt. In order to provide some reliable reference for the deep and edge prospecting work of the mining area,based on the geological and exploration results of the mining area,the regional metallogenic geological background and deposit geological characteristics,the relationship between strata,structural,magma and mineralization is discussed from the aspects of metallogenic material（ metallogenic element and metallogenic fluid）,energy,medium,channel（ ore-conducting structure）,space（ ore-bearing space）,besides that,the metallogenic model of the Pb-Zn deposit is studied. The study results show that：（1）the strata distributed in the mining area is mainly for Anjiacha Formation Jiaogou Layer（ D_2a^2） of Middle Devonian and Tertiary System（ T）,among them,the upper（ D_2a^（2-2）） of Anjiacha Formation Jiaogou Layer of Middle Devonian is the ore enriched strata;（2）the deposit is controlled by strata and structures significantly,the whole occurrence,scale and thickness of the deposit vary greatly,the deposit form is complex and changeable along the direction and striking and trending,the deposit is characterized by expansion,contraction and pinch-out reappearance,most of the deposits are occurred with the shapes of cystic and lenticular;（3）the deposits in the mining area are mainly controlled by Anjiacha Formation Jiaogou Layer（ D_2a^2） of Middle Devonian and inter-layer fracture zone,Huangtushan-Liangdang Fault and Huangzheguan deep and large fault,Huangshuling granite diorite in Indo-Chinese Epoch and magmatic hydrothermal;（4） based on the comparison analysis results of the Pb-Zn deposit in Huixian County and the others in Xicheng Ore-field,the genesis of the Pb-Zn deposit is defined as hot water sedimentary modified Pb-Zn deposit;（5）ore-bearing strata and its lithological combination characteristics,the iron carbonate phyllite layers with yellowish-brown exposed to the surface in mining area,the northern part of Rentushan-Jiangluo large fault,the ore-bearing strata（ carbonate strata） exposed to the surface in the mining area are the main favorable prospecting indicators of the mining area. Based on the above discussion results,the prospecting directions of the mining area is analyzed,it is show that：（1）the effective controlling methods of the deep conceal ore-bodies in the mining area are drilling and tunnel;（2）the prospecting potential of the east and west of the deposit is good,the exploration level of the north of the deposit is lower than other parts,so,it is necessary to increase exploration volumes;（3）during the periphery prospecting process of the deposit,the engineering control depth of the west of the deposit can be increased,while the engineering control depth of the east of the deposit can be decreased;（4）the prospecting potential of the blind ore-body in the mining area is huge,the favorable prospecting method is using comprehensive geophysical and geochemical methods to delineated the anomalies,and adopting surface verification and pit ore drilling verification methods to control the ore-bodies,so as to obtain the ideal prospecting results.
出处
《现代矿业》
CAS
2018年第1期33-37,共5页
Modern Mining
关键词
西成矿田
铅锌矿
成矿模式
矿床成因
隐伏矿体
盲矿体
深部找矿
Xicheng Ore-field, Pb-Zn deposit, Metallogenic model, Deposit genesis, Conceal ore-body, Blind ore-body, Deep prospecting
