南岔金矿床地质特征

GEOLOGICAL FEATURES OF THE NANCHA GOLD DEPOSIT

南岔金矿床是吉林省内首次发现的构造蚀变岩型金矿,它与南岔铁矿床属同一矿区,铁与金相毗邻(有的铁矿层破碎后含金)。1959年以来,在南岔铁矿床多次评价工作中做过金属量测量、重砂、水系沉积物取样工作,圈有金异常。1983年我所金矿室在该区进行了1:5万水系沉积物测量和重砂测量,圈出金和辰砂等套合异常。1984年我所化探队在区内进行土壤测量,并采残坡积重砂样验证。对金光谱分析结果进行数据处理。

The Nancha gold deposit belongs to commercial alteration type gold deposit which is the first to be found in the Laoling Group in the southeastern part of Tonghua area. The discovery of it provides a good example for searching for the alteration type gold deposit in this area. The orebodies exposed on the surface in the Nancha gold mine are small in scale and lower in grade,and distributed intermittently in group in the northeastern i(?)ctonic altered zone. The orebodies with high-grade great thick- ness are at the deep level of the mine. The structure is complicated, and the vein rocks are developed in this mine. Main mineralization includes arsenopyrite, pyrite and limonite; main alterations are carbonatization, silification can decoloration of rocks. The above-mentioned mineralization and alteration indicate the multiphase formation characteristics. The typomorphic mineral can be represented by acicular and fine long columnar arsenopyrite with a rhombus cross section. The stucture and texture of orestone are very complicated. Results of geochemical measurement in the mine indicate that in the felsite and schist areas, sections of the increase in contents of Au, Ag, As, Sb, Bi, etc. should be attached great attention.