上黑龙江盆地地质特征和金成矿作用的东西差异分析

上黑龙江盆地位于大兴安岭北部,是一个由陆源碎屑物填充和沉积而成的中生代构造型断陷盆地,其形成和演化受蒙古—鄂霍茨克造山带制约。盆地内赋存有石油、天然气、煤、金、银、铜及其他一些非金属矿产。通过分析盆地的形成和发展演化过程,结合目前盆地内已发现的金矿床(点)成矿特征,认为在地层和构造等地质特征方面,盆地在以长缨—依林—龙河一带为界的东西两侧存在差异性,因此在矿床成因和成矿特征方面有所不同。通过总结东西区金矿床(点)的成矿特征,指出在西部区应主要寻找以老基底为成矿围岩的铜、金矿床和以二十二站组地层为围岩的蚀变岩型和石英脉型金矿床;在东部区应主要寻找以火山岩地层为围岩的蚀变岩型岩金矿床,同时兼顾西部区所有的岩金矿床类型。研究认为,东部区具有较大的找矿潜力,是寻找大型—超大型岩金矿床的有利地区。

The Differences of Geological Characteristics and Gold Mineralization Between the East and West Part of the Upper Heilongjiang Basin

The Upper Heilongjiang Basin is a faulted basin in the northern of Daxinganling Montains.It is a downfaulted basin of Mesozoic tectonic by the terrigenous clastic filler and the deposition，its formation and evolution is constrainted by Mongolia-Okhotsk orogen.The basin exists petroleum，natural gas，coal，gold，silver，copper and other non-metallic mineral.Through the analysis of the formation and development of the basin evolution and mineralization characteristics of gold deposits（dot） had been found in the basin，we suggested that there is diffrence on the east and west part of  the basin（devided by the Changying-Yilin-Longhe） on formation，structure and other geological features，which caused the difference in the genesis and metallogenic characteristics.Based on the summary of the mineralization characteristics on the east and west part of  the basin，we come to the conclusion that the exploration work shoud concentrated on looking for the old basement wall rock mineralization Cu，Au deposit and a 22 station Formation for the surrounding rock in the eastern area；but altered rocks and quartz vein type gold deposits in the western area；and volcanic strata surrounding rock altered rock type gold deposit in the eastern region，as well as rock gold deposits including rock gold deposit types in the western district.The eastern region has large prospecting potential，which is the favorable areas to find a large and a very large rock gold deposits.