甘肃省礼县田家河砂金矿床地质特征及富集规律  

Geological Characteristics and Enrichment Laws of Tianjiahe Placer Gold Deposit in Lixian County,Gansu Province

作　　者：徐小健 宋红莎 XU Xiaojian;SONG Hongsha(Gansu Mining Development Research Institute,Lanzhou 730000,Gansu,China)

机构地区：[1]甘肃矿业开发研究院,甘肃兰州730000

出　　处：《西北地质》2020年第3期175-183,共9页Northwestern Geology

摘　　要：阐述了甘肃省礼县田家河一带砂金矿床的地质特征、第四系地质、地貌条件与成矿特征,分析了各类型松散堆积物的成因、分布特征,对砂金的富集规律和成矿特征进行了总结,通过对混合砂含砾率、砾石度、含泥量等进行了测定,对矿体厚度、品位在纵向上、垂向上的变化特征进行了分析。探讨了成矿物质来源、砂金富集部位和补给方向及搬运距离。田家河砂金矿床产于第四系全新统河床相及河漫滩相中,成因类型属河流冲积型,形态类型属河床、河漫滩型,成矿时代为第四纪全新统;全新世开始,地壳上升幅度极小,河流侧蚀作用增强,使含金地质体和各级阶地的剥蚀物被搬运、分选,并在谷底堆积形成田家河砂金矿。该砂金矿的发现和评价为该区寻找相似类型的砂金矿床提供了找矿标志和找矿模式。This paper mainly expounds the geological characteristics,Quaternary geology,geomorphic conditions and metallogenic characteristics of the Tianjiahe placer gold deposits in Lixian County,Gansu Province,analyzes the genesis and distribution characteristics of various types of loose deposits,and summarizes the enrichment laws and metallogenic characteristics of placer gold.Through the determination of gravel content,gravel degree and mud content of mixed sand,the variation characteristics of the thickness and grade of ore body in Longitudinal and vertical directions are analyzed.This paper finds out the source of ore-forming materials,the enrichment location,the supplying direction and transporting distance,etc.Tianjiahe placer gold deposit developed in the Quaternary Holocene riverbed and flood plain facies.it is river alluvial type,and riverbed and flood plain type as well.The metallogenic epoch is quaternary Holocene.In the Holocene,the crust rose slowly,while the lateral erosion of the river enhanced.All gold-bearing geologic bodies and terraces were transported and sorted,thus formed the Tijiahe placer gold deposit at the bottom of the valley.The discovery and evaluation provide prospecting criteria and a prospecting model for similar type of placer gold deposits in this area.

关 键 词：砂金矿床 田家河砂金矿床 地质特征 富集规律 

分 类 号：P618.51[天文地球—矿床学]