内蒙古塔布格金异常区地质、地球化学特征及找矿前景

Analysis of geological and geochemical characteristics in Tabuge Au anomaly,Inner Mongolia and its prospecting indications

在1∶5万土壤测量和矿产重点检查的基础上,对塔布格地区的AP22号金异常结合成矿地质特征开展了研究,发现该Au异常元素组合配套好,特征显著,多元素异常空间结构与其他成型金矿床地球化学异常空间结构可对比,可见该异常区具备较好的找金矿前景。该金异常空间分布严格受上二叠统方山口组地层控制,金矿化体主要赋存在英安质火山尘埃凝灰岩内。该地区晚二叠世属活动大陆边缘的火山弧,阿拉善变质基底在该时期受到中亚造山带碰撞造山作用的强烈影响和改造,发生物质再循环而形成喷出岩,成矿作用亦随之发生。尽管如此,在该地区的地质找矿历来都未给予古生代地层足够的重视。因此,在阿拉善地块区今后的找矿科研工作中,应注意加强对海西—印支期喷出岩含矿性的评价。

Based on the 1 ： 50 000 scale soil measurement and priority examination of minerals, researches on the anomaly of AP22 in the Tabuge District and the metallogenic geological characteristics are carried out.The results showed that this Au anomaly has a good cross combination, a remarkable characteristic and a good comparison of its spatial structure of multielement anomalies with those of geochemical anomalies in molding gold deposits, indicating this area has good prospecting potentials for gold deposits. The spatial distribution of this Au anomaly is strictly con- trolled by the strata of Fangshankou Formation, Upper Permian. Gold mineralization body is hosted mainly in the dacitic volcanic dust tuff. The study area is located in volcanic arc along the active continental margin at late Permian, the Alxa metamorphic basement was affected and reformed by the collision orogeny of Central Asian orogenic belt, the ex- trusive rock was formed in the material recycling process,in which mineralization also happened. Even so, no attention has been paid to the paleozoic strata in this area in prospecting and exploration, so the paper holds the point that more attention should be paid to the bearing potentiality evaluation in Hercynian-Indosinian extrusive rocks in future pros- pecting and exploration work in the district.