HYDROTHERMAL ORE-FORMING SOLUTION OF SOME GOLD DEPOSITS IN SOUTHERN LIAONING STUDIED WITH FLUID INCLUSION

Maoling gold deposit occurs in the second member of the Gaixian Formation of Proterozozic Liaohe group. In the mining area there is Indosinian porphyritic-ike granite. The Mineralization of the Maoling gold deposit can be divided into four stages. Inclusions are present in mineralization stage Ⅰ and Ⅱ as primary two phase inclusions about -4μm in size. In Maoling gold deposit metallogenetic temperature and pressure ranges respectively from 327° to 513℃ and 512×10⁵ to 1234×10⁵ Pa in the stage Ⅰ,from 325°to 407℃ and from 668×10⁵ to 1322×10⁵Pa in the stage Ⅱ. The metallogenetic temperature in Huangjiayingzhi gold deposit 0.8km east to Maoling gold deposit ranges from 325°to 407℃,and the pressure from 782×10⁵ to 1302×10⁵ Pa. The ore fluid of the Maoling gold deposit and the Huangjiayingzhi gold deposit is regarded to be of H₂O-NaCl-CO₂ system. The Jinchanggou gold deposit occurs in the contact zone of the first member of the Gaixian Formation of Liaohe group with a porphyritic-like granite. The mineralization can be divided into three stages. The gold mineralization is dominantly in stage Ⅰ. Its primary fluid inclusion consists mainly of two-phase inclusion and three -phase gas,H2O and liquid COt inclusion. The two sorts of inclusion are about 5 to 6μm in size. The metallogenetic temperature ranges from 325 -335℃ and the pressre from 1080×10⁵ to 1360×10⁵ Pa. The ore fluid is of H₂O-NaCl-CO₂ system. The amount of peaks of decrepitation temperature curve of the fluid inclusions is in positive correlation with Au content of gold quartz vein. Molarity of gas components CO,CH₄,CO₂,N₂,O₂, H₂ of the fluid inclusions in the Maoling gold deposit is reducing with mineralization evolution. CO₂/H₂O value of fluid is in positive correlation with and SO₄^2-/Cl^- value of fluid inclusions is negative correlation with Au content of gold quartz vein. We could deduce from the content of K⁺,Na⁺ and Ca²⁺,the value of SO₄^2-/C^l-and Cl^-/F^-ratio,and geological setting that the ore fluid is composed mainly of magmatic water mixed with groundwater and that it is of low salinity,low acidity arid strong reduction environment in the Maoling and Huangjiayinzi gold deposits,and low salinity,high acidity and strong oxidation environment in Jinchanggou gold deposit.