Typomorphic Characteristics Of Pyrite And Deep Ore Prognosis Of The Shuangwang Gold Deposit, Shaanxi Province

The Shuangwang gold deposit is located at the junction of the Yangtze plate, the Qinling continental block and the North China plate, and is a representative large-scale gold deposit of auriferous albite breccias type in the Fengtai ore field. Ore bodies, which assume vein like and lenticular forms in the plane, mainly occur in Devonian Xinghongpu Group, comprised of sandstone, metasandstone, albitite and slate. Based on systematic sampling from five new drill of north and south breccia zones in the Shuangwang breccias-type gold deposit, this paper mainly studies the crystal form, thermoelectricity and trace elements of pyrite, forecastes the deep deposit, and puts forward the following conclusions:(1)The crystal form of pyrite is relatively uncomplex, including cube, octahedron, pentagonal dodecahedron and their composite combination, and the main crystal habit is {hk0}. Overall, the occurrence rate of crystal form from high to low is {hk0}, {100}, {111}.(2)The thermoelectric conductive type of pyrite in north and south breccia zones is mainly N-P type, with ranging from-200 to 300 uV??-1 and-200 to 50 uV??-1 respectively. In vertical direction, the rate of emergence of P type shows certain regular changes; the thermalelectrical property parameters of pyrite appears a significant variation; the average degree of denudation is greatly different in the five drill holes.It is indicated that there is a better exploration prospecting in the deep of drill holes 18, 30 and 40 in No.9 and No.8 orebodies in south breccias zones; and it is indicated that the drill hole 52 has no ore body extending to the depth and the deep of drill hole 63 may have small-scale ore body.(3)By using eight kinds of trace elements such as Sb, Ba, Cu, Pb, Zn, Mo, Bi, and Co regarded as gold indicator elements, this paper primarily discussed the concentration distribution of trace elements, the vertical zoning sequence of primary halos, the vertical variation of the zoning rate of primary halos, the vertical change rule of the geochemical parameter, and finally combined with the graphical method of 3-end-mumber diagram it shows the character of spatial distribution of trace elements in different drill holes. With regard to south breccia zones, it is suggested that the ore body of drill hole 18 is thinning out gradually to depth, with higher degree of mineralization in 950 meters; the deep of the drill hole 30 might have bead-shape ore bodies, with higher degree of mineralization in 980 meters; the ore body of drill hole 40 still extends toward depth without pinching out, with higher degree of mineralization in 850 meters. As for north breccia zones, it is suggested that the head and rear halo elements in drill holes 52 and 63 both are relatively small, the degree of mineralization in north breccia zones is weaker than in south breccia zones, and the metallogenic environment is unstable. In detail, the breccia body of the drill hole 52 has some degree of mineralization within the scope of control levels, without extension of ore bodies to depth; the breccia body of the drill hole 63 has certain exploration prospecting from the control levels to the deep.