摘要
[目的]位于华北克拉通南缘的小秦岭金矿田是仅次于胶东金矿田的第二大金矿田,有着重要的经济与战略价值。[方法]通过野外地质调查和室内综合研究,在前人研究的基础上,对不同类型金矿床进行划分,从区内金矿床的时空分布入手,统计近年来国内外学者对区内主要金成矿的定年数据,概括总结区域内金的成矿规律。[结果]本研究以断裂构造对金矿的控制为主线,将金矿床划分为石英脉型、蚀变千糜岩型和破碎蚀变岩型。将小秦岭金矿田金矿由西自东分为四个矿带,分布特点为南北成带,东西展布,构造控制,脉型为主。成矿年龄统计显示小秦岭金矿的成矿年代主要集中在237~204 Ma和161~120 Ma两个时间段。[结论]研究表明:(1)区域上的重大构造事件(印支、燕山两期构造运动)和区域内主要的两组EW、NE向断裂共同造就了如今金矿床的空间分布及矿体的产出特征,两组断裂叠加部位为接下来找矿预测的重点。(2)将区域内金成矿分为两期,第一期中晚三叠世(印支期)237~204 Ma为金矿床的初步富集,印支期造山作用导致区内EW向构造体系;第二期晚侏罗世-早白垩世(燕山期)161~120 Ma为金矿床的改造再富集,燕山运动叠加改造形成区内NE-NNE向断裂。
[Purposes]Located in the southern margin of North China Craton,Xiaoqinling gold field,only next to Jiaodong gold field,is the second largest gold field,which has important economic and strategic value.[Methods]Based on the field geological survey and indoor comprehensive research,different types of gold deposits are divided on the basis of previous studies.Starting from the temporal and spatial distribution of gold deposits in the area,the dating data of main gold mineralization in the area by domestic and foreign scholars in recent years are collected,and the metallogenic law of regional gold is summarized.[Findings]Based on the control of fault structure on gold deposits,gold deposits are divided into quartz vein type,altered chylite type and broken altered rock type.The gold deposits in Xiaoqinling gold field can be divided into four ore belts from west to east,which are characterized by north-south belt,east-west distribution,structural control and vein type.The metallogenic age statistics show that the metallogenic age of Xiaoqinling gold deposit is mainly concentrated in 237-204 Ma and 161-120 Ma.[Conclusions]This study show that:①Regional major tectonic events(Indosinian and Yanshanian tectonic movements)and two main groups of EW and NE trending faults in the region jointly create the spatial distribution of the present gold deposit and the output characteristics of the ore body,and the superposition of the two groups of faults is the focus of prospecting and prediction in the future.②The gold mineralization in the region can be divided into two stages.In the first stage,the gold deposit was preliminarily enriched in the Middle Late Triassic(Indosinian)237~204 Ma,and the Indosinian orogeny led to the EW-trending tectonic system.161~120 Ma of the second stage Late Jurassic-Early Cretaceous(Yanshanian)was the reenrichment of gold deposits,and the Yanshanian movement superimposed to form NE—NNE trending faults in the area.
作者
郑远方
ZHENG Yuanfang(School of Earth Science and Resources,Chang'an University,Xi'an 710054,China)
出处
《河南科技》
2023年第9期59-64,共6页
Henan Science and Technology
基金
陕西省潼关县幅(I49C002002)“1∶25万区域地质调查(修测)”(202001)。
关键词
地质特征
矿床分布
成矿时代
小秦岭金矿
geological features
distribution of deposit
metallogenic age
Xiaoqinling gold deposit
