小秦岭金矿矿田构造发育特点及其控矿特征

通过收集和分析小秦岭金矿田地质资料,重点对典型矿床不同标高探矿工程进行系统研究,探讨了该矿田的控矿构造特征。研究认为,受褶皱构造控制,区内含金石英脉多位于杨砦峪—大月坪—金罗斑复式背形轴部或背形局部侧转处;矿田内部控矿断裂发育可分为成矿前断裂(早期韧性剪切带)、成矿早期断裂(中期脆韧或韧脆性剪切带)和主成矿期断裂(晚期脆性断裂)3个时期,主要控矿断裂大致可分为近东西向、北东向、北西向和近南北向共4组;区内矿体和矿床的大小直接由构造带及单条断裂的规模决定,同时因构造活动期次、构造变形类型和强度的不同,造成区内矿脉赋存状态各异以及矿化不均衡现象普遍存在。研究成果可为本区开展大比例尺成矿预测提供借鉴。

TECTONIC DEVELOPMENT AND ORE-CONTROLING CHARACTERISTICS OF XIAOQINLING GOLD FIELD

Through analyzing the collected geological data of xiaoqinling gold field, the different levels of exploration engineering on typical ore deposits were studied systematically and the ore-controlling tectonic characteristics of the mine field were discussed. The research shows that under the control of the folds, most auriferous quartz veins are located at the axes or corners of Yangzhaiyu-Dayueping-Jinluoban compound antiform. The development of ore-controlling faults inside the mine field can be divided into three stages: pre-minerogenic faults (the early ductile shear zone), early minerogenic faults (the middle brittle-ductile or ductile-brittle shear zone) and main metallogenic faults (the late brittle fault zone). Accordingly the main ore-controlling faults can be roughly divided into four groups: nearly EW, NE, NW and NS. The sizes of the ore bodies and ore deposits are directly determined by the structural belts and the scale of one single fault in the area, and because of the difference in the tectonic activity stages, tectonic deformation types and strength, the veins are in different occurrence state and the mineralization imbalance phenomenon is widespread. These research results can provide reference for carrying out metallogenetic prediction in large scale in this area.