东西长约800 km,南北宽100 km的冈底斯斑岩铜钼成矿带,由于近年来一系列大型-超大型斑岩铜钼矿床(驱龙、冲江、厅官等)和夕卡岩-斑岩复合型铜铅锌钼矿床(甲马等)的发现,已经成为国内外多地质学家研究的热点地区,是研究碰撞造山作用与成矿关系的很好的场所(侯增谦等,2001,2006a,b,c;莫宣学等,2003;李光明等,2004;Hou等,2003,2008;Qin等,2005;Li等,2006;Qu等,2007;侯增谦和王二七,2008;Tafti等,2009).

Recently, series of major breakthroughs for porphyry copper exploration have been made in the Gangdese Metallogenic belt in Tibet. Alteration and mineralization ages of the Gangdese porphyry-skarn Cu(Mo) deposits concentrate in the range of 30-12 Ma, formed in the extension environment of late stage of collision between India and the Asian continents or the transitional environment from the post-collisional compression setting to strike-slip extension. However, the independent porphyry molybdenum deposit associated with the collisional setting has not been reported so far. This paper studies the ore-bearing porphyries, the types and horizational and vertical zonation of hydrothermal alteration, the characteristics of hydrothermal vein system and mineralization, according to the systmatic fieldwork and the mapping work of the drilling holes. The granitic porphyry is the ore-forming intrusion with intensive alteration of 9 km2 in area. It concludes that, Sharang porphyry molybdenum is single porphyry molybdenum without any other important accompanying metal resources and it has been formed in the main collisional setting around 55 Ma. This study compares the scale of alteration and the intensity of mineralization with the same type of molybdenum deposits. Based on the comparisons and the results of TEM and induced electrical survey, the Sharang porphyry molybdenum deposit has rather large vertical extension to 800 m in the depth and showes excellent metallogenic conditions and great potential for further exploration. The establishment of the Sharang single porphyry molybdenum deposit will enrich the metallogenic pedigree of the giant Gangdese porphyry metallogenic belt. This discovery has a great significance for regional research and prospecting.

引言三江地区是我国重要的多金属成矿区之一,倍受地学界的广泛关注.在矿床地质特征研究基础上,本文对三江北段的达日通铜矿、玉龙铜矿和中段的小干箐金矿进行了同位素年代学研究.结果显示,上述三个矿床的成岩-成矿年龄均为40 Ma左右,与区域内为数众多的矿床一致,为新生代印度-欧亚大陆碰撞造山作用的产物.