南京栖霞山铅锌银多金属矿床的生物成矿作用

BIOMETALLOGENESIS OF Pb Zn Ag POLYMETALLIC DEPOSIT OF QIXIASHAN IN NANJING

许多学者探讨过菌藻生物参与形成南京栖霞山铅锌银多金属矿床的预富集作用。然而，生物成矿作用是一个随地质作用的发展而发展演化的过程。本文详细研究了矿床中的矿化生物以及矿石中的吸附有机质，证实它们源自菌藻生物。结合非打开性的红外和荧光光谱方法以及打开性的ＧＣ－ＭＳ分析，重点研究了矿床中发现的有机包裹体，检测出成矿流体中的系列生物标志化合物，证实成矿流体中的有机质也源自菌藻生物。根据成矿流体中有机质特征，矿石中成矿元素间的关系以及有机质中所含的金属元素，论证了这些源自菌藻生物的有机质、有机流体对成矿元素的活化迁移和还原沉淀作用，建立了生物－有机质－流体成矿系统。

Biological pre enrichment of metals in the Pb Zn Ag polymetallic deposit of Qixiashan in Nanjing has been previously discussed.As biometallogenesis is a developing process together with geological processes,this paper mainly deals with migration and reduction by organic matter and organic fluid derived from bacteria and algae.The mineralized organisms and organic matter absorbed in ores in the deposit are systematically investigated,which reveals that they are all derived from bacteria and algae.Combining non destructive analyses such as infrared and ultraviolet fluorescence microspectroscopy with destructive ones such as GC MS,the authors focus on the hydrocarbon inclusions developed in the deposit.Series of biomarkers in the ore forming fluid are identified,indicating their algal and bacterial sources.The basic analyses include the characteristics of organic matter in metallogenic fluid,the relationship among metallogenic elements and the distribution of metals in organic matter.Biometallogenesis other than pre enrichment is thereby clarified to form an organism organic matter fluid (OOF) metallogenetic system.