Study Of Alteration Minerals And Pyrite Genetic Mineralogy In Dongyang Gold Deposit,Fujian,China

The Dong yang gold deposit is located in Wuyi polymetallic metallogenic belt,which was firstly found among rhyolite porphyry and external contact zone in 2011.This paper is based on "The old mine and periphery prospecting " project of China Geological Survey.By studying the phengite in different occurrences and different generation pyrite typomorphic characteristics,we can get the following understandings:(1)By near infrared mineral analysis instrument,the main alteration minerals is mica and illite,both acount of 85% in mining area.Compared with alteration mineral percentage mapping and the spatial distribution of ore bodies,we found that the gold orebody and mica as well as illitesecondly have a close relationship in the spatial distribution.Alteration mineral zoning shows that mica belt has a most close relationship with gold orebody and illite zone is located in the mica with peripheral,closer relationship with ore bodies.(2)Electron probe test was carried out on the mica to study its composition.We found that the phengite is major mineral.Phengite gradually turns to iron mica in orebody,metallogenic environment exchanges from oxidation to reduction.(3)Pyrite is a perfoliate metal mineral,copper yellow pentagonal dodecahedron and cube collection in main metallogenic period(?+?).Pyrite pyroelectric typomorphic studying suggests that the number of P type pyrite reached 90%,pyrite formation temperature has focused on the 140-280 ?,which reflects the ore deposit belongs to low temperature ore deposit.Content and ratio of pyrite As-Co-Ni refflects that the origin is msinly volcanic hydrotherm,accompanied by sedimentary origin.Trace elements and rare earth elements integrated that the ore-forming hydrothermal fluid is Cl reduction conditions.The Au element is extracted from early hydrothermal activation and formd auriferous hydrothermal.The gold formed in the first generation of pyrite replaced by secondary and tertiary generation.Then the gold activation migration again,precipitate with two or three generation in reductioncondition.(4)Pyrite thermoelectric coefficient mapping found that thermoelectric coefficient and the discrete degree of pyrite and gold is closely related to taste value space position distribution,which have a certain to deep prospecting prediction effect.According to pyrite thermoelectric coefficient of 207-203 exploration line,a new gold grade high value area was found,which has a g Alteration mineral,Pyrite,Typomorphic characteristics,Dongyang gold deposit ood prospecting potential.