【摘要】 黔西南为我国重要的卡林型金矿产区,有机质丰富为该区矿床的重要特点之一。综合利用多种有机地球化学指标,选取六处典型的金矿床及四处古油藏进行了详细的有机地球化学分析。结果表明:矿床中有机质主要有分散型有机质和聚集型有机质两大类,可能来自于海相菌藻类与陆相植物的混合,并在强还原-还原环境下沉积;金矿床中有机碳的含量与样品为矿石或围岩无关,但与岩性有关;绝大多数样品中R⁰均大于2%,表明有机质处于过成熟阶段;氯仿沥青"A"含量、有机转化率、Ts/（Ts+Tm）、C₂₉Ts/(C₂₉H+C₂₉Ts)、升藿烷指数、甾烷异构化指数等多个参数也反映有机质处于成熟-过成熟阶段,并且矿石中有机质的成熟度要高于围岩中,暗示成矿热液对于有机质成熟具有促进作用。综合分析认为大规模烃类运移携带金成矿可能并不存在,有机质对金矿床形成的作用主要体现在对金的预富集、金离子的还原、还原硫的供给及提供可容空间等方面。更多还原

【Abstract】 The Southwest Guizhou Province is an important enrichment area of the Carlin-type gold deposits,in which usually contain abundant organic matter.In this study,a detailed organic geochemistry investigation has been performed on six typical Carlin-type gold deposits and four paleo-oil reservoirs in Southwest Guizhou.The results indicate that organic matter in the gold deposits can be divided into two major types,i.e.,dispersed and enriched organic matter,which are mainly sourced from the mixing of marine bacteria and algae and terrestrial plants,and deposited in a strong reducing environment.The content of organic matter in the deposits has no relationship with the sample types,i.e.,ores or wall rocks,but is related to the lithology of samples.Most of the samples have R° values larger than 2%,indicating that the organic matter is at the over mature stage.Chloroform bitumen "A" content,organic matter conversion rate,Ts/（Ts+Tm）,C₂₉Ts/(C₂₉H+C₂₉Ts),homohopane index,sterane isomerization index all reflect that the maturity of organic matter in the ores is higher than in the wall rocks,implying that the ore-forming hydrothermal fluids probably accelerate the maturation of organic matter.The results indicate that the migration of hydrocarbons may not be the main reason for the formation of gold deposit,and the roles of organic matter in the ore-forming process are mainly reflected in the preconcentration of Au,the reduction of Au ion,the supply of sulfur and accommodation space for Au sedimentation.更多还原