【作者】 李斌；

【导师】 杨兴科；

【作者基本信息】 长安大学 ， 构造地质学， 2018， 硕士

【摘要】 凤县北部庞家河-马蹄沟一带金矿处于秦岭造山带的核心部位,位于华北板块与华南板块之间的商丹加里东结合带,唐藏-商丹构造混杂带内。庞家河金矿现已进入深部寻找盲矿和外围找矿阶段,马蹄沟金矿现已进入详查阶段。通过对庞家河深部与外围找矿和马蹄沟金矿的详查研究对比,提出找矿方向。通过野外地质路线、实测剖面、矿硐、岩芯等调查研究,室内测试和综合研究,对西秦岭东段凤县北部马蹄沟-庞家河一带金矿的矿区地质构造、矿床相关的岩石学、矿物学等手段入手,深入研究该金矿的矿床地质特征,探索其控矿构造特征。结合研究区与本次控矿构造专题研究进行取得的调研资料,进行综合研究,总结控矿构造特征、矿床特征、探讨成矿模式,指出找矿方向。通过多方面综合研究,取得如下认识:1、马蹄沟金矿含矿层位为目前认为的早古生代罗汉寺岩群（Pz₁L）,庞家河金矿含矿层位为泥盆系舒家坝组（Dsh）,虽然二者时代不一致,但含矿岩性主要为蚀变糜棱岩,蚀变糜棱岩化千枚岩,主体颜色为灰绿色,矿石结构构造相似,蚀变类型一致,S同位素显示均为地层硫来源。初步将二者划为同一成矿类型。2、以糜棱岩化发育、千枚理揉皱变形强、出现大量同斜紧闭褶皱为特征,在马蹄沟金矿区划出了两条与F9变形特征相似的两条脆-韧性剪切带（RF1、RF2）,基本控制马蹄沟金矿的平面展布。总体展布方向为NWW向,产状未知。剪切带内主要岩性为早古生代罗汉寺岩群c段。可见强烈构造变形,如糜棱岩化、膝折、旋转碎斑系、层间揉皱等。3、一般认为含金剪切带分为三个阶段（据吴美德等,1989）。研究区内的剪切带主要为区域上印支期的近EW向罗汉寺-瓦窑上（F9）脆-韧性复合断裂及其派生脆-韧性剪切带。矿化带内岩石均不同程度发育蚀变与糜棱岩化,局部地段可达到糜棱岩,对应为含金剪切带第二阶段。马蹄沟金矿TC47-1,BT24-3处均发现含金石英脉,出现后期脆性叠加富集。沿近EW向脆-韧性剪切运动在构造片理化带中形成各式张性裂隙,成矿热液沿这类裂隙运移沉淀成矿,使得矿体产状与地层产状近一致。庞家河-马蹄沟金矿为脆-韧性剪切带叠加后期热液型金矿。4、在控矿因素综合分析基础上,建立了庞家河-马蹄沟一带金矿区找矿模型,并可将矿区内的预测找矿靶区基本确定为沿矿区内出露的各个脆-韧性剪切带以及与金矿化关系密切的蚀变发育地段。并依据矿体分布规律,脆-韧性剪切带及断裂发育程度、岩石片理化强度、岩石变形强度,蚀变发育强度以及蚀变的叠加情况等,在矿区深部和外围圈定出找矿靶区。更多还原

【Abstract】 The gold deposits in the Pang Jiahe-Matigou area in the northern part of Fengxian are located at the core of the Qinling Mountains orogenic belt,which are located in the Shang Dan Jia-Li zone between the North China and Southern China plates,and in the Tang-Tibet-Shang Dan structural mixed zone.The Pangjiahe gold deposit has entered the deep blind area and peripheral prospecting stage,and the Matiogu gold deposit has entered the stage of detailed investigation.Based on the detailed investigation of the deep and peripheral prospecting of the Pangjiahe and the Matigou gold deposit,the prospecting direction is put forward.Through the investigation and study of field geological route,measured section,mine cavern and core,indoor test and comprehensive study,the geological features of the gold deposit in the Matigou and Pangjiahe in the northern part of Fengxian are studied in detail from the geological structure of the mine area and the related petrology and mineralogy of the deposit,exploring the characteristics of ore control structure,combined with the research data obtained in the study area and the special study on the ore control structure,the comprehensive study is carried out to summarize the characteristics of the ore control structure,the characteristics of the deposit,the metallogenic model and the prospecting direction.Through comprehensive studies,we have gained the following achievements:1.The ore bearing strata of the Matigou gold deposit are in the early Paleozoic Luohansi group（Pz₁L）.The ore bearing strata of the Pangjiahe gold deposit are the Devonian Shu Jiaba group（Dsh）.Although the two era is not consistent,the ore bearing lithology is mainly altered mylonite and altered mylonite,the main body color is gray green,and the ore structure and structure are similar,and the types of alteration are consistent.The two are preliminarily classified as the same metallogenic type.2.With the development of mylonitization,a large number of syndiagonal closed folds are characterized by a thousand rubbing and wrinkle deformation,and two strips of brittle ductile shear zone（RF1,RF2）,similar to the deformation characteristics of F9,have been made in the Matigou gold mining area,which basically control the plane distribution direction of the Matigou gold mine.The overall distribution direction is NWW direction and the attitude is unknown.The main lithology in the shear zone is the C section of the early Paleozoic Luohansi rock group.There are strong deformation structures,mylonitization,knee fracture,rotating spot,and interlayer wrinkling.3 It is generally believed that the gold bearing shear zones can be divided into three stages（according to Wu Meide et al.,1989）.The shear zones in the mining area are mainly in the Indosinian-varisi stage-the near EW toward the Luohansi-Wayaoshang（F9）brittle ductile shear zone and its derived brittle ductile shear zone.In the mineralized zone,The rocks in the mineralized zone are altered and mylonitization in varying degrees,and the mylonite is the second stage of the gold bearing shear zone.Gold bearing quartz veins were found at TC47-1 and BT24-3 of the Matigou gold deposit,which appeared to be brittle and superimposed at the later stage.All kinds of tensional fractures are formed in the tectonic strip along the near EW to brittle ductile shear movement.The metallogenic hydrothermal fluid moves along this kind of fissure to precipitate and deposit,which makes the occurrence of the ore body coincide with the formation of the formation.The Pangjiahe-Matigou gold deposit is a hydrothermal gold deposit in the superposition of brittle ductile shear zone.4.On the basis of comprehensive analysis of ore control factors,the ore prospecting model of the gold area of Pangjiahe and Matigou area is established,and the target area of the prediction and prospecting in the mining area can be basically defined as the brittle ductile shear zone which is exposed along the mining area and the alteration and development area closely related to the gold mineralization.According to the distribution law of ore body,the brittle ductile shear zone and fracture development degree,rock fragmentation strength,rock deformation strength,alteration development strength and alteration superposition,etc.,are determined in the deep and outer circle of the mining area.更多还原