中国矽卡岩型白钨矿矿床成矿基本地质特征

矽卡岩型钨矿在世界钨矿床中占有重要地位,是分布最为普遍并最具经济价值的一类钨矿床。中国钨矿居世界首位,矽卡岩白钨矿已占全国钨矿总储量的60.62％,是潜在的尚待开发利用的一类矿产资源。本文总结了中国该类矿床基本特征,探讨了时空分布、物质来源与形成环境,与世界著名矽卡岩钨矿床进行了对比,按热液来源进行了分类。认为开展有关研究,以达逐步开发利用这一潜在资源,可以提到议事日程上来了。

BASIC GEOLOGICAL CHARACTERISTICS OF SKARN-TYPE SCHEELITE DEPOSIT IN CHINA

Skarn-type scheelite deposit is most widespread and of the greatest economic value, occupying an important place among all tungstun deposits in the world. China's tungstun deposits rank first in the world. Skarn-type scheelite accounts for 60.62% of the total tungstun reserves in China, which remains to be exploited and utilzed.Skarn-type scheelite deposits are distributed widely in China, and have been found in more than half of its 29 provinces. They are mainly concentrated in South China and some in Northeast, Northwest and other parts of China, constituting the major part of scheelite zone of the Circum-Pacific metallogenic belt. The ore-controlling horizons are largely developed in the Devonian and Cretaceous. The mineral was formed in a wide range of geological time, but mainly during the Yanshanian period. Spatially, skarn-type scheelite deposits can be classified as one metallogenic province and six metallogenic zones in China. This paper discusses the relationship between the distribution of the deposits and geotectonics, and the source of mineralforming materials and compare the deposits in China with those famous in the other parts of the world. Compositionally, the tungstun deposits of China have a slightly higher acidity. The tungstun deposits associated with I-type granite are predominantly medium-and small-scaled, while the large-and medium-scaled ones are mostly associated with the S-type granite. Comparatively speaking, some famous skarn-type scheelite deposits in the world were formed at a somewhat deep depth and higher temperature, with better developed subsequent hydrothermal alteration and higher ore grade. According to the origin of hydrothermal solution and ore-bearing formations, the skarn-type scheelite deposits are classified and the scheelite deposits associated with ma-gmatic hydrothermal solutions and those associated with migmatized hydro-thermal solution are schematically compared in the paper.