秦岭卡林型金矿床及相关问题探讨

A TENTATIVE DISCUSSION ON THE CARLIN TYPE GOLD DEPOSITS IN QINLING AND RELATED PROBLEMS

鉴于目前对沉积岩型金矿、卡林型金矿概念和类型划分存在分岐，该文在对秦岭沉积岩区浸染状金矿研究基础上，主张将沉积岩为容矿岩石的金矿床划分为广义和狭义两类：沉积岩型金矿床是具有广义内涵的一类金矿，包容了从沉积－轻微改造，到沉积－强烈改造的一类热液金矿；可划分四种亚类：卡林型、变质细碎屑岩型、热水沉积岩型、脉状体型。卡林型金矿床是狭义内涵的金矿类型，属于沉积岩型金矿类型中的重要亚类；在区域金成矿密集区内，可构成卡林型矿床地球化学系列。建议不要将沉积岩型金矿和卡林型金矿相互代替使用或等同起来。秦岭沉积岩区卡林型金矿与美国卡林典型矿床有较好的类比性。矿床具有沉积－轻微改造的中—低温热液成因特征。

In view of the differences existent in the concept and classification of sediments hosted gold deposits and Carlin type gold deposits, this paper, based on the study of disseminated gold deposits in Qinling sedimentary area, suggests classifying gold deposits hosted by sedimentary rocks into two types, i.e., broad sense deposits and narrow sense ones. The sediments hosted gold deposits are of broad sense type, which consists of sedimentary weakly reformed and sedimentary intensely reformed hydrothermal deposits and might be divided into four subtypes, viz., Carlin type, metamorphosed fine clastic rock type, sedex type and vein type. The Carlin type gold deposits are of narrow sense type and constitute an important subtype in sediments hosted gold deposits. In gold concentrated areas of the regional metallogenic belt, the Carlin type gold deposits might form their geochemical series. It is suggested that the terms “sediments hosted gold deposit” and “Carlin type gold deposit” should not be used as synonyms. The Carlin type gold deposits in Qinling area are well correlatable with the Carlin type gold deposits in U.S.A. These deposits are characterized by sedimentary weakly reformed mesothermal epithermal origin.