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测定了冲绳海槽Jade热液区(127°04.5′E,27°15′N,水深1300～1450m)热液硫化物的元素和铀系同位素组成.结果表明,含硫酸盐矿物的热液硫化物(样品HOK1和HOK2)具有LREEs相对富集的特点,所研究的热液硫化物样品(除样品HOK1外)属富Zn型热液硫化物.与其他海区的富Zn热液硫化物相比,具有高Zn,Pb,Ag,Cd,Au和Hg含量,低Fe,Al,Cr,Co,Ni,Sr,Te,Cs,Tl和U含量,以及极低的210Pb放射性比度值和210Pb/Pb比值的特点.在以闪锌矿为主的热液硫化物中,稀有元素Hf与U,Mn元素之间以及分散元素Ga与Zn之间均存在显著的正相关关系,且Au,Ag与Fe-硫化物有关,低温阶段有利于Au,Ag的富集.同时,Fe-Bi之间和Zn-Cd之间的正相关关系,不受矿物组合变化的影响.根据热液硫化物中210Pb/Pb比值(3.99×10-5～5.42×10-5),结合其具有U同位素(238U含量1.15×10-6～2.53×10-6,238U放射性比度值1.07～1.87dpm/g,234U放射性比度值1.15～2.09dpm/g,234U/238U比值1.07～1.14)存在,而232Th和230Th均处于背景水平的事实,得到冲绳海槽Jade热液区热液硫化物样品的形成年龄在0.2～2ka之间.
The isotope composition of hydrothermal sulfide and hydrothermal sulfide in Jade hydrothermal zone (127 ° 04.5’E, 27 ° 15’N, water depth 1300 ~ 1450m) in the Okinawa Trough was measured.The results show that hydrothermal sulfide (Samples HOK1 and HOK2) are relatively enriched in LREEs, and the hydrothermal sulfide samples studied (except for HOK1) are Zn-rich hydrothermal sulfides compared with Zn-rich hydrothermal sulfides in other sea areas With high content of Zn, Pb, Ag, Cd, Au and Hg, low content of Fe, Al, Cr, Co, Ni, Sr, Te, Cs, Tl and U as well as extremely low 210Pb radioactivity ratio and 210Pb / Pb ratio, there is a significant positive correlation between rarefaction elements Hf and U, Mn elements and dispersed elements Ga and Zn in the sphalerite-based hydrothermal sulfide, and Au, Ag and Fe-sulfide, the low temperature stage is conducive to the enrichment of Au and Ag.At the same time, the positive correlation between Fe-Bi and Zn-Cd is not affected by the change of mineral assemblage.According to 210Pb / Pb ratio (3.99 × 10-5 ~ 5.42 × 10-5), combined with its U isotope (238U content of 1.15 × 10-6 ~ 2.53 × 10-6, 238U radioactivity ratio of 1.07 ~ 1.87dpm / g, 234U radioactivity Ratio of 1.15 ~ 2.09dpm / g, 234U / 238U ratio 1.07 to 1.14) exist, 232Th and 230Th are in fact the background level, to give the age formed specimen Okinawa Trough hydrothermal sulfide Jade hydrothermal region between 0.2 ~ 2ka.