中国岩浆硫化物矿床新分类与小岩体成矿作用

Classification of Magmatic Sulphide Deposits in China and Mineralization

of Small Intrusions TANG Zhongli 1, *, YAN Haiqing 1, JIAO Jiangang 1 and LI Xiaohu 2

1 Chang’an University , Xi’an , Shaanxi 710054

2 Lanzhou University, Lanzhou, Gansu 730000

Abstract: Many important metal resources, such as Ni (Cu, Co), PGE, exist in magmatic sulfide deposits, are a hot spot in geological research. We divide the magmatic sulphide deposits in China into four types

according to their tectonic setting, intruding way, ore deposit mode, main metallogenic elements. The four types are

as follows: (1) Small-intrusion deposits in paleo-continent; (2) Small-intrusion deposits in continental flood basalt; (3) Small-intrusion deposits in orogenic belt; and (4) The deposits associated with ophiolites. On the basis of the classification, we put forward that the main magmatic metallogenic type in China is small-intrusion metallogeny, and describe its characteristics from small intrusions related concept, three geologic settings, three volcanic-intrusive metallogeny not only widely distributes in mafic-ultramafic intrusions, but also has an important economic value and scientific significance in intermediate-acid intrusions.

Key words: magmatic sulfide deposits, classification, small intrusions, metallogenesis

1 Introduction

Previous classifications of magmatic sulphide deposits in China are mainly based on metallogenesis, considering the controlling factors of geological settings and rock assemblage (Tang, 1997; Liu et al, 1998). These types of classification play a positive role in further prospecting and research. However, as the development of geological study, the factors of geological settings, volcanic-intrusive assemblages and small-intrusion metallogeny are more and more important in recognizing and discovering ore deposits. It is necessary to put forward a new classification to stress these factors.

During the 20th century, geologists pay more attention to looking for magmatic sulphide deposits associated with large-size layered complex, because the biggest magma deposits formed in large-size layered complex, explore China in different degrees, without discovering large layered complex except some magmatic sulphide deposits in small intrusions, among which there is the third largest nickel deposit (Jinchuan deposit) in the world. The area of the Jinchuan intrusion is only 1.34 km 2. Then, geologists pay more and more attention to small-intrusion metallogeny.

This article is mainly describe the above two issues.

2 Geological Settings

Types of magmatic sulphide deposits in China are shown in Table 1 and distribution of typical magmatic sulfide deposits in China is seen in Fig. 1.

2.1 Small-intrusion deposits in paleo-continent

Types of magmatic sulphide deposits in China are shown in Table 1 and distribution of typical magmatic