应用GIS研究中国原生金矿与砂金矿的关系  

APPLICATION OF GIS TO TEMPORAL AND SPATIAL ANALYSES OF PRIMARY AND PLACER GOLD DEPOSITS OF CHINA

作　　者：周军[1] 高凤亮[1] 沈杉平[2] 

机构地区：[1]长安大学地球科学与国土资源学院,陕西西安710054 [2]中国石化总公司新星西北分公司开发处,新疆乌鲁木齐830011

出　　处：《长安大学学报（地球科学版）》2003年第4期48-54,共7页

摘　　要：　参阅近千件文献建立中国金矿数据库(ACCESS)及构造格架、地层、火成岩等图层与属性表(ArcInfo、ArcView),对其进行时空分析。中国砂金矿主要形成在第四纪,而原生金矿则主要形成在侏罗—白垩纪(占原生金总储量64.6%)。空间分析发现,超过半数的原生金矿金储量(52.5%)分布在砂金矿0～40km缓冲域中,其中5～25km缓冲域中为33.2%,而0～5km缓冲域中仅3%,表明原生金矿主要为5～25km内砂金矿提供矿质。此外,中国砂金矿金储量916.9t,占总储量的11.6%,明显少于澳大利亚的25.2%,认为与后者原生金矿主要形成在太古代和古生代有关;中国东部中新生代(尤其第三纪)地壳减薄导致此前形成原生金矿的掩埋,可能是造成砂金较少的另一原因,这两种推测与中国缺乏古砂金相吻合。量化分析结合地质背景研究表明,西秦岭、松潘-甘孜地块、拉萨附近为依据砂金找原生金的远景区。Gold databases of China, including 1,500 gold deposits, were built under ACCESS and nation-wide map layers with their attribute tables, concerning the tectonic framework, stratigraphy and igneous rocks, were also created under ARCINFO and ARCVIEW on the basis of nearly a thousand of references. The temporal analysis shows that Chinese gold placers were formed in the Quaternary whereas lode gold reserves are mainly of Jurassic-Cretaceous age, forming 64.6% of the national total (based on 246 Au-only and associated lode Au deposits with available age data). The spatial analysis reveals that 52.5% of lode gold reserves of the national total (ca 1,000 Au deposits) are distributed within the 0～40km buffer zone of gold placers and those in the 5～25km buffer zone amount to 33.2%, indicating that in general lode gold deposits principally provided gold for placers within their 5～25km distance. The total placer gold reserves of China (around 500 placer deposits) amount to 916.9 t (contributing 11.6% of the total Au reserves from both lode and placer deposits) and are notably less than that of Australia (25.2%), which is inferentially ascribed to that Australian lode gold deposits are primarily of Archaean and Palaeozoic age and eastern China, as a major gold producer, experienced large-scale crust thinning in the Mesozoic and Cenozoic (particularly in Tertiary) after the Jurassic-Cretaceous gold veining peak. The 5～25 km buffer zone of gold placers and possible deeper buried depth of lode gold deposits as a whole in eastern China should be macroscopically considered in the gold exploration though why there are less lode gold reserves in the 0～5km buffer zone of placers is still uncertain. Through quantitatively evaluating and geological setting analyzing of 24 gold placer concentration areas in China Western Qinling, the Songpan-Ganzi Block and the Lhasa Region are selected as a prospecting area for further studies of gold placers in order to locate unknown lode gold resources there.

关 键 词：GIS 原生金矿 砂金矿 中国 

分 类 号：P618.51[天文地球—矿床学] P208[天文地球—地质学]