Application of hydrocarbons in metallogenic and mineral resource exploration research
烃类组分在金属矿床的成矿理论和矿产勘查研究中的应用

There is plenty of evidence that hydrocarbon components are very widespread in nature.For example,they occur in various kinds of surface and near-surface rocks and soils,contemporary active hot water areas and volcanic erupted gas in contemporary submarine chimneys and sea troughs,plutonic basic-ultrabasic rocks and basalt inclusions,and even in carbonic chondrite.Therefore research on hydrocarbons should not be only confined in energy sources such as oil,gas and coals but should be extended into the research fields of various metallic deposits and their fluids.Compared with other gaseous components such as CO_2,H_2S,N_2 and H_2, hydrocarbons are characterized by the diversity of their components and stable properties,and meanwhile the correlation characteristics and partitioning regularity between various hydrocarbon components are important parameters in the geological evolution of the fluids (environmental factors such as oxidation-reduction conditions,temperatures and pressures).In order to show the comprehensive characteristics of hydrocarbon components and their tiny variations during fluid mixing and superimposition evolution,a research concept of establishing the standardized background for hydrocarbons is proposed in the paper in an attempt to take the Emeishan basalt with the characteristics of mantle-derived fluids as the standardized background,which is similar to choosing chondrite for establishing the normalized REE background.The actual applications in several typical metallic deposits such as the Gejiu tin polymetallic deposit in Yunnan,Dachang tin polymetallic deposit in Guangxi and Ma'anqiac gold deposit in Shanxi demonstrate that the research method can visually reflect the difference in hydrocarbons of various geological bodies and regularity of evolution and can also sum up the simple macroscopic anomaly characteristics of hydrocarbons and develop them into a method for studying the superimposition and modification, portioning model and correlation regularity of the hydrocarbon components,use the hydrocarbon components only to characterize the involvement of organic matter in metal mineralization and develop them into a tool and means applied in the study of ore material sources,ore fluid evolution and ore-forming processes and characteristics.