Collaborative Research: Modeling the Chemistry, Origin, and Evolution of Subduction Zone Fluids Rising Beneath the Mariana Forearc

研究人员将利用马里亚纳前弧泥火山上升的流体化学来推断俯冲板顶部的压力-温度和化学条件，以限制浅俯冲带的过程，并估计通过马里亚纳前弧的质量通量。 他们将通过1）在弧前下的一系列蓝片岩相条件下，对沉积物和玄武岩进行水-岩相互作用的热力学模拟，使用观察到的泉水成分和恢复的变质岩作为约束; 2）模拟这些变质流体在上升过程中与哈氏玄武岩的渐进反应;（3）比较俯冲洋壳玄武岩和沉积物的成分与泉水和上升蛇纹岩所代表的通量。

The investigators will use the chemistry of fluids rising through mud volcanoes on the Mariana forearc to infer pressure-temperature and chemical conditions at the top of the subducting slab, to constrain processes in the shallow subduction zone, and to estimate mass fluxes through the Mariana forearc resulting from this process. They will do this by 1) thermodynamic modeling of water-rock interaction under a range of blueschist-facies conditions beneath the forearc, for both sediment and basalt, using the observed spring compositions and recovered metamorphic rocks as constraints; 2) modeling of the progressive reaction of these metamorphic fluids with harzburgite during their ascent; and 3) comparing the composition of subducting oceanic basalt and sediment with fluxes represented by the springs and the ascending serpentinite.