大兴安岭南段锡矿成矿特征及找矿前景

Metallognetic Characteristics of Tin and Ore-Search Prospect in the Southern Part of Da Hinggan Mountains

大兴安岭南段是我国重要的铅锌银锡多金属成矿集中区,但长期以来找矿重点一直以铅锌银为主,锡矿基本没有列入重点找矿对象。近几年该地区锡矿找矿取得重大进展,相继发现了维拉斯托大型锡铷铌钽矿和园林子北山、边家大院中型锡矿等,显示锡矿勘探的良好前景。锡矿与铅锌银矿存在密切的时空关系,并具一定的矿化分带特征。前人通过矿床地质特征及成岩、成矿年代学研究,也论证了锡与铅锌银应属同一成矿系统的产物。本文基于这种认识,分析研究最新锡矿勘查和研究成果,充分利用区域锡地球化学异常资料,总结了该地区锡成矿地质特征、成矿规律,认为锡成矿地质体为晚侏罗世-早白垩世中酸性侵入岩体,锡矿产出的有利部位为岩体顶部、与围岩接触带、锡地球化学异常、铅锌银矿产地的深部,各项有利信息表明,区内锡矿具有很大资源潜力。据此,圈定了9个锡矿找矿远景区,其中赤峰克什克腾(黄岗、维拉斯托、拜仁达坝为代表)、白音诺尔-浩布高和查干哈达-先锋远景区锡资源潜力大,具有较好的找矿前景。

The southern part of Da Hinggan Mountains is the most important lead-zinc- silver-tin polymetallic concentration area in China. In long term, the prospecting in this area is dominated by lead-zinc-silver, without tin in the list. In recent years tin ore prospecting has made significant progress in this area, as some major deposits have been found such as the tin-ploymetallic deposit in Weilasituo and tin deposit in the north mountain of Yuanlinzi and Bianjiayuan. There are close temporal-spatial relationship between tin and lead-zinc-silver within the deposits. Previous work demonstrated that the tin, lead, zinc, and silver should belong to the the same metallogenic system. Based on this understanding, this work uses the new research and exploration results and geochemical anomaly data to study geology and mineralization of tin deposits in this area. The results suggest that the geological body bearing tin ore is Late Jurassic- Early Cretaceous intrusive rock, and the favorable localities of tin occurrence are the top of rock mass, contact zones of rocks, tin geochemical anomalies and the deep subsurface of known lead-zinc- silver deposits. The information shows that this area has great potential of tin resources. Based on it, this paper determines 9 prospect areas，among which Keshiketeng in Chifeng, Baiyinnuoer-Haobugao and Chaganhada-Xianfeng have larger prospecting potential.