投稿时间：2014-02-17
修订日期：2015-03-06
网络发布日期：2015-07-02
中文摘要:虎家尖银金矿床为赣东北地区典型的受一组NE向韧脆性断裂破碎带控制的中低温热液型银金矿床。矿床赋存于中元古界双桥山群浅变质岩中,矿脉均产于断裂带内,具舒缓波状、膨大缩小、分支复合、尖灭再现等特征。研究表明,控矿断裂具有长期性、多期次和继承性活动的特点,经历了早期压扭性塑性变形、中期张扭性脆性变形和晚期压扭脆性变形3个演化阶段。通过地质调查、数据处理和成矿构造分析,认为成矿期石英多金属硫化物阶段的构造应力场为: σ1为190°∠2°,σ2为90°∠78°,σ3为280°∠12°,差应力约为71.3~99.3 MPa;银多金属硫化物阶段构造应力场方向与石英多金属硫化物阶段基本相同;石英碳酸盐阶段构造主应力方向表现为NW-SE向挤压。文章总结了断裂对矿体空间定位、似等距性分布、矿体侧伏等方面控矿规律,断裂面凹凸转换部位为成矿有利地段,矿体在水平方向和垂向上似等距性分布明显,并且整体大致呈45°向北东深部侧伏。结果表明,在矿区50线深部及北东部深部找矿潜力巨大,矿区外围北东向韧性剪切带有后期脆性变形叠加的断裂破碎带为找矿有利地段。这对赣东北地区同类型矿床的深部及外围找矿具有一定的指导和借鉴意义。
Abstract:The Hujiajian Ag (Au) ore deposit, located in the northeast of Jiangxi, is a medium-low temperature hydrothermal type Ag (Au) ore deposit controlled by a set of tectonic compressed fractures within the NE-trending ductile-brittle shear zone. The deposit occurs in the epimetamorphic rock of the middle Proterozoic Shuangqiaoshan Group. Orebodies occur in the fracture zone and are characterized by smooth wave form, apparent expanding and narrowing, branching and compounding, thinning out and reappearing, and the mineral composition is complex. In view of the fact that the fractural structure is the most important ore-controlling factor, the author tried to probe into characteristics and ore-controlling regularity of the ore-controlling fractures so as to provide scientific basis for the ore prognosis at the depth and in the periphery. Studies show that the NE-trending ore-controlling fractures have the characteristics of prolonged activity, multiphase and inherited features, and have experienced three stages of evolution: ① at the early stage, they behaved as compressive shear faults, accompanied by plastic deformation; ② at the middle stage, they turned into tenso-shear faults characterized dominantly by brittle deformation; ③ at the late stage, compresso-shear movement occurred in association with plastic deformation. According to underground geological work, indoor data processing and metallogenic tectonic analysis, the stress field at the quartz-polymetallic sulfide stage of the metallogenic phase had the orientation of σ1: 190°∠2°, the orientation of σ2: 90°∠78°, the orientation of σ3: 280°∠12°, and the differential stress size about 71.3~99.3 MPa; the direction of the stress field at the silver-polymetallic ore-forming stage of the metallogenic phase was similar to that of the quartz-polymetallic sulfide stage; the stress field at the quartz-carbonate stage of the metallogenic phase had NE-SW compression. The authors then summed up the ore-controlling regularity in such aspects as orebody spatial orientation, nearly equidistant distribution of orebodies and the lateral plunging of orebodies. The concave and convex conversion parts of the fracture surface are the favorable locations for mineralization, the equidistant distribution of orebodies is obvious in both horizontal and vertical directions, and the orebodies wholly plunge northeastward at the angle of 45°. It is shown that there exists huge potential of prospecting in the depth of No. 50 exploration line and the northeast part of the mining area, and the NE-trending fracture zone which is a high-strain ductile shear zone with a brittle deformation superposition in the periphery of the mining area is favorable for prospecting. The results achieved by the authors have certain guidance and reference significance for the deep and periphery prospecting.
keywords:geology characteristics of the fracture tectonic stress field ore-controlling regularity Hujiajian Ag (Au) ore deposit
文章编号：
中图分类号：P613;P618.41;P618.51
文献标志码：
基金项目:本文得到虎家尖银矿委托项目"江西万年县虎家尖银、金矿区深部及外围找矿综合研究及成矿预测"和内蒙古自治区莫旗拉抛等8幅1:5万区域矿产地质调查资助项目(编号: NMKD2010-3)联合资助
引用文本：
高荣臻,吕新彪,杨梧,吴建亮,李春诚,尚世超,刘文.2015.江西万年虎家尖银金矿床断裂构造特征及其控矿规律[J].矿床地质,34(3):449~464GAO RongZhen,LÜ XinBiao,YANG Wu,WU JianLiang,LI ChunCheng,SHANG ShiChao,LIU Wen.2015.Characteristics and ore-controlling regularity of the fractural structure in Hujiajian Ag (Au) ore deposit, Wannian County, Jiangxi Province[J].Mineral Deposits34(3):449~464
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