内蒙古迪彦钦阿木钼矿的地质特征和矿床成因

论述了迪彦钦阿木钼矿的矿床地质特征,分析了环状矿体、围岩蚀变、矿石特征与钼矿化之间的关系,认为该矿床具有斑岩型矿床的一般特点。矿床的成矿年龄为晚株罗世(156.2±1.4 Ma),在成矿时代上、成矿规律方面,与二连-东乌旗成矿带上的其他斑岩型钼矿相似。侏罗纪末或白垩纪初,强烈的弧后伸展,诱发大规模陆内裂陷活动,在该区域形成断陷盆地,并且伴随着一定规模的中酸性岩浆活动。而本区的岩体侵位较深,受断陷盆地内早期构造影响的矿体富集,热液流体与岩性差异较大的岩石接触,形成了不规律的蚀变分带。解释了为什么钼矿体赋存在地层当中,而未发现规模较大相关岩体的原因。认为该矿床仍属于斑岩型矿床,形成于陆内裂陷构造环境,与深部岩浆活动有成因联系。

Geological characteristics of the Diyanqinamu molybdenum deposit in Inner Mongolia and its mineralization genesis

This paper describes geological characteristics of the Diyanqinamu molybdenum deposit in Inner Mongolia. The relationships between molybdenum mineralization and circular structure of ore bodies, wall rock alteration and ore characteristics are analyzed. The results suggest that this deposit has general characteristics of porphyry type deposits, which has the metallogenic age of Late Jurassic (156.2±1.4 Ma). The metallogenic epoch and metallogenic regularity are similar to other deposits of porphyry type molybdenum mines in the Erlianhot - Dongwuqi metallogenic belt. In this area, inland rift-depression induced by strong back arc extension, fault basin formation and acidic magmatism happened during the Late Jurassic or Early Cretaceous. Intrusion and ore bodies were controlled by the early structure of fault basins. The ore-forming hydrothermal contact with different lithologies formed different alteration zones. According to orebody characteristics, ore fabric, ore composition and wall rock alteration, it is suggested that this deposit belongs to porphyry ore deposits, which formed in an intracontinental rifting environment, bearing genetic relationship with magma activity at depth.