中蒙边界地区铜区域地球化学分布及远景区预测

Regional Geochemistry and Distribution of Anomalies Related to Potential Copper Mettallogic Areas in China–Mongolia Border Region

中蒙边界地区成矿地质条件优越,是世界上重要的金属成矿省和全球三大斑岩型铜(金、钼)成矿带之一,资源潜力巨大。中蒙合作边界地区1:100万地球化学填图采集了海量的地球化学数据,为该地区研究元素分散富集、成矿趋势、资源评价和环境变化提供基础数据。本文依托中蒙边界1:100万地球化学填图数据,探讨铜在不同构造单元内的地球化学参数及区域地球化学异常特征。全区铜元素中位值和平均值分别是20.1×10^-6和21.6×10^-6;东西准噶尔弧盆系、阿尔泰构造带、阿尔泰南缘弧盆系、戈壁阿尔泰弧盆系、准噶尔地块、北山—戈壁天山弧盆系6个构造单元铜含量中位值和平均值均高于全区铜含量,是铜元素的富集构造成矿带优势区;根据85%累积频率,圈定出91个铜地球化学异常区,其中34个铜地球化学异常达到地球化学省规模,Oyu Tolgoi、Tsagaan Suvarga等大型铜矿均产在地球化学异常内,根据铜地球化学异常分布模式为该区寻找铜等多金属矿床提供了重要选区。本项研究填补了中蒙边界地区铜元素地球化学分布的空白,同时为两国边境地区铜等多金属矿床对比提供基础数据。

China-Mongolia border region has excellent ore-forming geological conditions and is one of the world’s important metal mineralization provinces and one of the world’s three major porphyry copper(gold and molybdenum)metallogenic belts.China-Mongolian cooperative 1:1000000 geochemical mapping project collected a lot of geochemical data,providing basic data for the study of element dispersion and enrichment,mineralization trends,resource evaluation and environmental changes in this region.This paper discussed the geochemical parameters of copper in different tectonic belts and the regional geochemical anomalies based on 1:1000000 geochemical data across the boundary between China and Mongolia.The median and average values of copper are 20.1×10^-6 and 21.6×10^-6.The median and average values of the eastern and western Junggar arc basin systems,the Altay tectonic belt,the arc basin system on the Altay southern margin,the Gobi Altay arc basin system,the Junggar block,and the Beishan–Gobi Tianshan arc basin system are higher than the values of other tectonic belts,showing that copper is enriched in those area.A total of 91 copper geochemical anomalies were delineated respectively based on the 85%cumulative percentage and 34 geochemical provinces that were selected.The work fills the gap in the copper geochemical distribution and provides important data for the comparison of ore deposits in this area.