Pyrite Typomorphic Characteristics And Metallogenic Prognosis On The Mengdehe Gold Deposits In Heihe City,Heilongjiang Province

Gold deposit is one of the important minerals in the world,and the ductile shear zone type gold deposit is an important type of it.Heilongjiang province Duobaoshan-Daxintun area is an important agglomeration of porphyry copper-gold deposit in China.There are many ductile shear zone type gold deposits distributed in the Nenjiang-Heihe tectonic melange belt of the area.The Mengdehe gold deposit is one of them.Predecessors have conducted researches on the chronology,metallogenic regularities,and genesis of gold deposits in the Mengdehe gold deposit.However,some researches on the mineralogy of the Mengdehe gold deposit are quite few.This paper mainly uses pyroelectricity probes to study pyrite and gold minerals,pyroelectricity study of pyrite was carried out by pyroelectricity instrument,and its structure study was researched by XRD powder diffraction.In-depth study of the cause of the Mengdehe gold deposit and the deep or peripheral Metallogenic potential and the forecast target area,this paper has obtained the following understanding:?1?The pyrite thermoelectric coefficient is between-288.4 and 310.6uV/?.The pyroelectricity type of pyrite is dominated by N-type,which shows positive zoning characteristics in space.the smaller value of dispersion indicates that the ore-forming environment is relatively stable,and the discrete characteristics show that there may be hidden ore bodies in the deep part.The isomorphic substitution of Fe with multitude Co is the main reason for the N-type pyrite and the increase of unit cell parameter a₀ in this area.?2?Gold minerals include natural gold and gold-silver tellurides,and gold-silver tellurides are the main minerals.Gold-silver tellurides consist of hessite?stuetzite?petzite?sylvanite?cavaverite,and are the products of mineralization and late mineralization.The complete gold-silver telluride combination implies a relatively sufficient supply of ore-forming fluids.The order of mineral formation is natural gold?hessite?stuetzite?petzite?sylvanite?cavaverite.Mineral particles are small and semi-self-shaped.The states of occurrence are included body gold,intergranular gold,and fissure gold,and is dominated by inclusion body gold.High quality of the natural gold suggests deep-source features.?3?Multitude Co Substance replacement Fe caused pyrite major component indicates iron loss,showing deep source features.Trace elements mapping shows the characteristics of metamorphic hydrothermal fluid in Mengdehe gold deposit.Mineralization temperature was determined between 117.5 and 355.8?.The empirical formula for the thermoelectricity and composition calculations shows that the ore body is currently eroded to the lower middle part.The spatial zoning of trace elements results in thermoelectric spatial banding.The Ag/Au ratio of pyrite as a whole is characterized by“small in shallowness and large in depth”.?4?The Mengdehe gold deposit is characterized by multiple stages of mineralization.Identifying upward migration directions of two metamorphic ore-forming fluids:the No.16exploration line southwest?elevation 410m?moves to No.152 exploration line northeast?500m elevation?;the No.152 exploration line South East?elevation 410m?runs to No.0 exploration line northwest?500m elevation?.?5?The northwestern shallow part of the No.0 exploration line of the Mengdehe gold deposit?elevation 450-500m?and the southwestern deep part of the No.0 exploration line?elevation 390-450m?,the northeast shallow part of the 160th exploration line?elevation470-510m?and the southeast deep part of the 160th exploration line?elevation 360-410m?.Looking from the northeast direction,these four areas are almost equally spaced.The target area delineated in this study happens to be the“beginning”and“end”of the two stages of ore-forming hydrothermal migration.