抄録
Annual hydrothermal flux of arsenic from back arc basins and mid-ocean ridges was estimated based on arsenic concentration of hydrothermal solutions and seawater circulation rate. Estimated values are (0.2-5.2)x1011 g/yr at island arc-back arc basins and (0.8-1.6)x109 g/yr at mid-ocean ridges. The estimated total hydrothermal input flux ((0.28-5.36)×1011 g/yr) is similar to or higher than that of river flux (0.78×1011 g/yr). Total input flux ((1.6-6.1)×1011 g/yr) is same in orders of magnitude to pyrite output flux ((1.3-2.9)×1011 g/yr). Subduction flux is estimated to be (4.0-8.2)×1010 g/yr. The comparison of subduction flux with hydrothermal flux from island arc-back arc basins suggests that the subduction flux from crust to mantle is small, compared with arsenic circulation in crust-ocean-atmosphere system.
