小兴安岭东安-乌拉嘎地区岩浆演化与金成矿作用

Magmatic evolution and gold mineralization in Dongan-Wulaga area of Xiao Hinggan Mountains

东安-乌拉嘎为小兴安岭重要Au成矿带,已发现多处大型岩金及砂金矿床,但对于Au成矿作用认识尚不统一。文章通过对该地区岩浆岩岩石学、岩石化学、成岩年龄、成矿年龄、构造背景等研究总结,进一步明确了成矿均与中生代岩浆作用有关。认为该地区存在2期截然不同的成矿作用,即T3-J1期(216~194 Ma)与中性脉岩有关的平顶山型金成矿作用,K1晚期到K2早期(107~97 Ma)与酸性岩浆活动有关的东安型、乌拉嘎型金成矿作用。通过岩浆构造背景及物质来源研究,建立了该地区岩浆演化过程及其与金成矿作用关系。文章指出在乌拉嘎地区应存在两种成矿作用,明确了找矿方向。

Dongan-wulagah is an important Au mineralization belt in Xiaoxingan, and many large Au and placer gold deposits have been found, but there is still no unified understanding of Au mineralization. based on the region of magmatic petrology, petrochemistry,diagenetic age,metallogenetic age and tectonic background research summary,further defined the closely associated with mineralization of ore-forming geological body, the mineralization is related to Mesozoic magmatism.the area thought to exist phase 2 distinct mineralization,the T3-J1(216 Ma-194 Ma) associated with neutral vein rockof pingdingshantype gold mineralization,Late K1-early K2(107 Ma-97 Ma) Dongan and Wulaga type gold mineralization associated with acidic magmatic activity.Through the study of magmatic tectonic background and material source,the magmatic evolution process and its relationship with gold mineralization in this area were established. It is pointed out that two kinds of mineralization should be distinguished in Wulaga area and the prospecting direction should be clarified.