中国岩浆硫化物矿床新分类与小岩体成矿作用

中国镍(铜、钴)、铂族等许多重要金属矿产都产出于岩浆硫化物矿床,该类矿床是矿床地质研究的热点之一。笔者综合构造背景、侵入方式、岩体规模、矿床模式、主成矿元素等因素,对中国岩浆硫化物矿床提出了新的分类:①古大陆内的小侵入体矿床;②与大陆溢流玄武岩有关的侵入体矿床;③造山带内小侵入体矿床;④蛇绿岩型矿床。认为小侵入体(小岩体)岩浆矿床是中国主要的矿床类型,并在此基础上,从小岩体矿床的相关概念、3种地质背景、3种火山岩_岩体_矿床组合形式以及成矿的主要因素等方面详细阐述了小岩体成矿作用。结合国内外勘查实践指出,小岩体岩浆矿床仍具有很大的找矿潜力,是中国应继续重点研究的主要矿床类型。最后,还讨论了小岩体矿床不仅在基性_超基性岩体中广泛发育,而且在中酸性岩体中也具有重要的经济价值和研究意义。

New classification of magmatic sulfide deposits in China and ore_forming processes of small intrusive bodies

Many important metallic resources, such as Ni (Cu, Co) and PGE, exist in magmatic sulfide deposits. Such ore deposits now constitute a hot spot in geological research. The authors have divided the magmatic sulfide deposits in China into four types based on such factors as their tectonic settings, intrusive forms, ore deposit modes and main metallogenic elements. They are: (1) small-intrusion deposits in paleo-continent; (2) small-intrusion deposits in continental flood basalt; (3) small-intrusion deposits in orogenic belt; and (4) deposits connected with ophiolites. According to this classification, the authors hold that the main magmatic metallogenic type in China is small-intrusion mineralization. This paper describes characteristics of this type from small intrusion-related concept, three geological settings, three volcanic_intrusive assemblages and ore-forming key factors. Based on ore exploration experience acquired both at home and abroad, the authors consider that there still exist great potentialities in the prospecting for small_intrusion deposits and that this problem deserves further study. It is also pointed out that small-intrusion ore-forming processes not only widely occur in mafic-ultramafic intrusions, but also have important economic value and research significance in intermediate-acid intrusions.