有机质在卡林型金矿成矿过程中的作用

卡林型金矿与有机质之间存在着密切的联系。在表生过程中，有机质对金的溶解、吸附和生物吸收作用是沉积、成岩过程中金在赋矿层位中初步富集的重要地质营力，腐殖酸可能是表生金成矿过程中重要的迁移因素。在热液作用过程中，原油形成和二次运移不可能是金成矿迁移的主要因素，但成烃及成油后期有机质的热成熟和裂解作用所产生的有机酸及Ｈ２Ｓ可能对金的淋滤和迁移起着不可低估的作用。矿体及围岩中有机质的高成熟度，以及矿床及围

ROLE OF ORGANIC MATTER IN THE CARLIN-TYPE GOLD MINERALIZATION

Organic matter is closely associated with Carlin-type gold mineralization.During the supergenic stage,the complexing,adsorption and uptaking of Au by organic matter might be important processes that controlled the enrichment of the gold in the host rocks during sedimentation and petrogensis.Humic acids may be important migrants in supergene gold ore mineralization.During hydrothermal stage,crude oil might not be important to gold migration,however,the organic acids produced by the maturation and decomposition of organic matter,as well as the H 2S produced in the thermochemical sulfate reduction and/or bacterial sulfate reduction processes,should be significant for gold leaching and migration,this is well worth further investigations.The high grade matruation of organic matters in the ores and the host rocks,as well as,the higher maturation of organic matters in mineralized host rocks relative to those of the unaltered rocks,suggest that the oil formation(if it had ever presented) proceeded the hydrothermal gold mineralization.During the precipitation of the gold,the pre-existing light hydrocarbons in anticlines and domes might be important reductants to gold precipitation.