The Geochemistry of Sulfur During Submarine Hydrothermal Alteration of the Troodos Ophiolite, Cyprus

海底热液系统中的海水-地壳反应可能会对海水中硫的质量和同位素组成产生重要影响，但由于缺乏数据和对这些系统中硫的了解，这种影响被忽视了。蚀变洋壳的俯冲作用也解释了弧状火山岩的~(34)S丰度和地幔硫同位素组成的不均一性，但对蚀变洋壳中硫的分布和同位素组成知之甚少。通过对特罗多斯蛇绿岩剖面的硫化物矿物学、硫含量和硫同位素组成的分析，以了解海水-地壳反应过程中硫的地球化学特征，并解决这些问题。拟议的结果将对海底样本的最新结果进行必要的检验。此外，蛇绿岩剖面将提供有关深部反应/上流带的重要新数据，这些数据是大洋样品套所缺乏的。这些带对形成大量硫化物矿床并喷发到海底的热液流体起着重要的控制作用。拟议的研究还将允许对预测热液系统深层补给区硫磺和34S富集岩区域的理论模型进行测试。从海底还没有观察到这样的岩石。

Seawater-crustal reactions in submarine hydrothermal systems may exert an important influence on the mass and isotopic composition of sulfur in seawater, but such effects have been ignored due to a lack of data and understanding of sulfur in these systems. Subduction of altered oceanic crust has also been suggested to account for the 34S-enrichments of arc volcanics and to produce heterogeneities in the sulfur isotopic composition of the mantle, but little is known about the distribution or isotopic composition of sulfur in altered oceanic crust. It is proposed to analyze the sulfide mineralogy, sulfur contents, and sulfur isotopic composition of a section through the Troodos ophiolite in order to understand the geochemistry of sulfur during seawater-crustal reactions and to address these problems. The proposed results will provide a necessary test of recent results from seafloor samples. Moreover, the ophiolite section will provide essential new data on deep reaction/upflow zones, which are lacking from the oceanic sample suite. Such zones exert important controls on hydrothermal fluids which form massive sulfide deposits and vent onto the seafloor. The proposed study will also permit testing of theoretical models which predict zones of sulfur and 34S enriched rocks in the deep recharge areas of hydrothermal systems. Such rocks have not yet been observed from the seafloor.