Pyrite Genetic Mineralogy And Vertical Contrast Of The Ultra-deep Drill Of Sanshandao Gold Deposit In Jiaodong

Based on the research of the Z96-6 ultra-deep drill hole of the Sanshandao gold deposit (the occurrence depth of the ore is -2626m～-2684m), the crystal shape, pyroelectricity, S-Pb isotope of pyrite and hydrothermal alteration are vertically contrasted over the span of 2700m in Jiaodong for the first time. The results are as follows:1.The pyrite crystal shape of the Z96-6 ore is all cube, the P-type proportion is an average of 68%, thermal electricity ratio is an average of 82.27μV/℃ (P-type is 168.85μV/℃;N-type is -105.832μ.V/℃); δFe=-0.41%,5S=-0.22%.Vertically downward, pyrite crystal shape turn from cube and pentagonal into cube; the P-type proportion decreases from 100% to 68% and the thermal electricity ratio greatly decreases from 232μV/℃ to 82.27μV/℃(P-type is 32μV/℃ to 168.85μV/℃) in thermoelectricity; δS obviously decreases and δFe slightly decreases; the pyrite presents obvious depletion of As,Cu, Zn in trace elements and the Co/Ni ratio of it increases from 0.7～1.2 to 1.4～1.9.2.The country-rock alteration presents that potassic feldspar alteration and silicification zone widen downwardly, but beresitization zone is narrowed; the geochemical characteristics of the ore present that SiO2, Al2O3, MgO has no obvious change, but of the deep shows obvious depletion of Na2O, CaO, P2O5 and enrichment of K2O in major elements, it suggests the deep has stronger alteration; the trace elements present slight depletion of Sr and slight enrichment of Zr, Hf, U, Ba, it suggests the enrichment of LILE and depletion of HFSE,such as La, Ce, Pr. In general, the metallogenic characteristics of the Sanshandao gold deposit are similar vertically, but undulately changed. And the mineralization is more developed in the shallow, and the alteration is more developed in the deep.3. The stable isotope of the deep of Sanshandao gold deposit present the δ34SV-CDT%=9.8%～11.6%o,208Pb/204Pb=37.885～37.959,207Pb/204Pb=15.478～15.492, 206pb/204pb=17.119～17.194 Vertically downward, the average value of δ34S decreases from 11.4 to 10.7, and there is no much different in Pb isotope. And it might suggests the country-rock contamination is weaken in the deep.