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东太平洋海底扩张中心七个多金属硫化矿床中48个热液沉淀物样品的金化学分析显示出独特的金富集作用,从两个多金属硫化矿床的样品中发现高的金含量:阿克西亚尔海山(北纬45°57′,西经130°02′)和埃克斯普洛雷洋脊南部(北纬49°45.6′,西经130°16.2′)。阿克西亚尔海山矿床顶部由二氧化硅、重晶石和闪锌矿组成的重160公斤的大样 Au 分析值高达6,700PPb,平均值为4,900PPb,埃克斯普洛雷洋脊南部中相似的样品 Au 分析值最高达1,500PPb,平均值为660PPb,这两个地区大范围样品的详细矿物学研究和金化学分析表明元素共生组合明显控制了金的沉积。金富集约200PPb 时,与高的 Cu(>1Wt%和 Mo(高达470ppm)有关;金富集>800ppb,与高的 Zn(>0.1Wt%)、Ba(>3Wt%)和 SiO_2(>20Wt%)有关;金富集>1,200ppb,与高的pb(>0.1Wt%)、Ag(>100ppm)、As(>300ppm)和 Sb(50—100ppm)有关。这两个地区金分析值最高的样品中,含有产在非品质二氧化硅基质中的晚期泉华状低温 pb、As、Sb、Ag 硫盐和 S,这些硫盐是金的可能携带者。已发表的其它产于玄武岩中的海底矿床(北纬21°,加拉帕戈斯裂谷,胡安·德富卡洋脊南部,因代沃洋脊)贫金(<20ppb)样品分析值与阿克西亚尔海山和埃克斯普洛雷洋脊南部的样品相比,金属和硫含量高,但二氧化硅低。在瓜伊马斯盆地,热液矿床产于比洋中脊玄武岩富金的沉积物上,但这些矿床的样品没有反映这种富集,其平均金分析值<20ppb。这里提出:金在高温(>300℃)、富铜铁硫化物中初步富集到约20ppb,后经晚期持续的低温(<250℃)流体活化转移,在近地表富二氧化硅、钡、锌的沉淀物中富集。使金活化需要合适的流体成分,而使金富集则需要有利的沉积机制。这些观测能解释在陆上一些古块状硫化矿床特定的矿石类型中出现金的高度富集。
The gold chemical analysis of 48 hydrothermal sediment samples from seven polymetallic sulphide deposits at the Eastern Pacific Seabed Expansion Center shows unique gold enrichment and high levels of gold are found from samples of two polymetallic sulphide deposits: West Seychelles Mountains (latitude 45 ° 57 ’north, longitude 130 ° 02’ west) and southern Exxon Ray Ridge (latitude 49 ° 45.6 ’north, longitude 130 ° 16.2’ west). The large Au sample of 160 kg, consisting of silica, barite and sphalerite at the top of the Aksayar seam deposit, reached as high as 6,700 PPb, with an average of 4,900 PPb, similar to the southern Exxon ridge Au samples of up to 1,500 PPb with an average of 660 PPb. Detailed mineralogical and gold chemical analyzes of a wide range of samples in both areas show that elemental symbiosis significantly controls gold deposition. Gold enrichment is about 200 ppb with high Cu (> 1Wt% and Mo up to 470ppm); gold enrichment> 800ppb with high Zn (> 0.1Wt%), Ba (> 3Wt%) and SiO_2 (> 20Wt% ), While gold enrichment> 1,200 ppb is associated with high pb (> 0.1Wt%), Ag (> 100ppm), As (> 300ppm) and Sb (50-100ppm) The samples contain late spring-like low-temperature Pb, As, Sb, Ag sulfur and S, which are produced in non-silica substrates, and these sulfur salts are potential carriers of gold.Produced in other basalts Analytical values of the seafloor deposit (<20 ppb) from the seabed deposits (21 ° Latitude, Galapagos Rift, southern Juan de Fuca Ridge, Indo Wave ridge) Metals and sulfur are higher in metals and sulfur but lower in silica than in samples south of the Pleasant Ridge. In the Guaymas basin, hydrothermal deposits are produced on basalt-rich sediments of mid-ocean ridges, but these deposits Of the sample does not reflect this enrichment, the average gold analysis of <20ppb. Here proposed: gold in the high temperature (> 300 ℃), rich in copper rich initial enrichment of about 20ppb, after the late sustained low temperature (< 250 ℃) fluid activation transfer in the near Enriched in sediments of surface-rich silica, barium and zinc, activation of gold requires appropriate fluid composition, and enrichment of gold requires favorable depositional mechanisms that can explain the evolution of some of the ancient massive sulphide deposits Gold is highly enriched in specific ore types.