地球化学块体与大型矿集区的关系——以东天山为例

通过在东天山15万km2的战略性深穿透地球化学调查共圈出大于1000km2以上的地球化学块体18处,其中铜-铅-锌-银地球化学块体5处,铜地球化学块体3处,铜-镍地球化学块体1处,金的地球化学块体4处,铀的地球化学块体3处,铂-钯地球化学块体1处,钨地球化学块体1处。有6处地球化学块体与已知矿集区相对应,新圈定的地球化学块体12处,其中有3处发现了新的矿床。根据这些块体与矿集区的对比得出如下结论:所有的已知矿集区都位于地球化学块体的范围之内,地球化学块体为矿集区的形成提供了丰富的物质基础;有矿集区的存在一定有地球化学块体的存在,但反过来有地球化学块体的存在不一定有矿集区的存在,地球化学块体是客观存在的,而矿集区是已经发现了一系列矿床并勘探到一定程度才能称作矿集区,因此,地球化学块体内可能会存在潜在的矿集区,这为利用地球化学块体预测新的矿集区提供了依据。

Relationship of geochemical blocks and ore districts: examples from Eastern Tianshan metallogenic belt, Xinjiang, China

Eighteen geochemical blocks have been delineated by a wide-spaced deep-penetrating geochemical survey in area of 150 000 km2 in the Eastern Tianshan metallogenic belts,Xinjiang,China.The area has 5 Cu-Pb-Zn-Ag,3 Cu,1 Cu-Ni,4 Au,3 U,1 Pt-Pd,and 1 W geochemical anomalies or blocks.Our results indicate that six geochemical blocks match the clusters of known large ore deposits clusters or districts.Newly discovered 11 blocks may have potential for copper,gold,uranium and tungsten ore deposits.The geochemical blocks with high metal concentrations are favorable for the formation of ore deposit cluster.Some geochemical blocks have no ore clusters yet.New deposits have recently been discovered in 3 of the 11 newly dilineated geochemical anomalies(blocks).They may have potential for future discovery of ore deposits.Ore-forming processes commonly affect large areas of the earth crust,resulting in large scale of geochemical anomalies.These large-scale geochemical anomalies can only be delineated by geochemical survey in large area,or promising ore districts might even not be noticed if geochemical mapping was carried out in a small area.