We observed the initial release rate of metals from four fresh (i.e., without long time exposure to the atmosphere) hydrothermal sulfide cores into artificial seawater. The sulfide samples were collected by seafloor drilling from the Okinawa Trough by D/V Chikyu, powdered under inert gas, and immediately subjected to onboard metal-leaching experiments at different temperatures (5 °C and 20 °C), and under different redox conditions (oxic and anoxic), for 1-30 h. Zinc and Pb were preferentially released from sulfide samples containing various metals (i.e., Mn, Fe, Cu, Zn, Cd, and Pb) into seawater. Under oxic experimental conditions, Zn and Pb dissolution rates from two sulfide samples composed mainly of iron disulfide minerals (pyrite and marcasite) were higher than those from two other sulfide samples with abundant sphalerite, galena, and/or silicate minerals. Scanning electron microscopy confirmed that the high metal-releasing sample contained several galvanic couples of iron disulfide with other sulfide minerals, whereas the low metal-releasing sample contained fewer galvanic couples or were coated by a silicate mineral. The experiments overall confirmed that the galvanic effects with iron disulfide minerals greatly induce the initial release of Zn and Pb from hydrothermal sulfides into seawater, especially under warm oxic conditions.

中文翻译：

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船上实验研究了新鲜的热液硫化物岩心向海水中的金属浸出。

我们观察到金属从四个新鲜的（即，没有长时间暴露于大气中）热液硫化物岩心向人造海水中的初始释放速率。D / V Chikyu通过冲绳海槽海底钻探收集了硫化物样品，在惰性气体下将其粉末化，然后立即在不同温度（5°C和20°C）以及不同氧化还原条件下进行了机载金属浸出实验（有氧和无氧），持续1-30小时。锌和铅从含有多种金属（即锰，铁，铜，锌，镉和铅）的硫化物样品中优先释放到海水中。在有氧实验条件下，两个主要由二硫化铁矿物（黄铁矿和镁铁矿）组成的硫化物样品中Zn和Pb的溶出率高于其他两个闪锌矿，方铅矿，和/或硅酸盐矿物。扫描电子显微镜证实，释放高金属的样品含有几对二硫化铁与其他硫化物矿物的电偶，而释放低金属的样品则含有较少的电偶或被硅酸盐矿物覆盖。实验总体上证实，二硫化铁矿物的电化作用极大地诱导了Zn和Pb从热液硫化物向海水中的初始释放，特别是在温暖的有氧条件下。