中国汞矿化主要特征及区域分布型式的初步认识

本文根据近年所收集的有关资料,在简述我国汞矿特点的基础上,对汞矿化的主要特征及区域分布型式作一初步探讨,以供参考。不当之处,敬请指正。一、我国汞矿的主要特点我国汞矿分布普遍,产出的地质环境各不相同,矿床类型多样。除具汞矿床所共有的某

A preliminary observation on the regional distribution regularity and the main characteristics of mercury mineralization in China

Mercury mineralizations are widespread in China. There have already been found plenty of mercury deposits or occurrences of various sizes and types, which evidently differ from the major mercury deposits at the rest of the world in some properties. During the evolution of continental crust in China, miscellaneous mercury mineralizations occur in different geological environments. Under the influence of their respective regional geological conditions and geochemical fields, they have shown unlike regional distribution patterns, resulting in different structural-metallogenetic belts. The mercury deposits within platforms and geosyncclines in China all bear the stamp of regional mineralization in such aspects as the wide diversity as well as the limitation of geological periods and types for the ore-bearing country rocks, the main ore-controlling factors, ore associations, types of the ore deposits, their relations to magmatic activities, etc. The main types of the mercury deposits in China are concentrated in the Wuling district in the southern part of Yangzi paraplatform, where an important regional distribution pattern is that mercury mineralizations are confined chiefly to areas near the axis of the anticlinorium of the mantle fold system or to the major fracture zones parallel to the axis, forming a mercury zone composed of NNE trending perallel banded systems. In most cases, mineralizations are obviously stratabound. Ore-bearing strata consist primarily of the Cambrian carbonate rocks. Ore associations are rather simple-the single mercury formation in most cases. The deposits are predominantly sedimentary-reconstructed or reconstructed. Mercury mineralizations are also localized in the complex geosynclinaJ fold areas, e.g. Sanjiang and Qinling fold systems. Mercury mineralizations are restricted to the regional fracture zones and their neighborhood within the structural active zones, especially the deep fracture zones with a regional scale, a deep-seated occurrence and a very long period of development. Regional mercury minerogenetic zones formed along-some of these fracture zones and are commonly found associated with polymetallic ore zones. Fracture structure is regarded as a chief ore-controlling factor. The ore-bearing country rocks belong to different geological ages and possess varied lithological characters. The ore assemblages are relatively complex, making up generally complex mercury-bearing formation. The ore deposits can be classifi,ed into a substantial number of types characterized by polygenesis. Some of the mercury mineralizations may have something to do with magmatic activities.