Department of Geosciences, Virginia Tech, Blacksburg, Virginia 24061, USA.
Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto, Ontario, Canada M5S 3B1.
Nat Commun. 2017 Jul 14;8:16107. doi: 10.1038/ncomms16107.
The hydrothermal alteration of mantle rocks (referred to as serpentinization) occurs in submarine environments extending from mid-ocean ridges to subduction zones. Serpentinization affects the physical and chemical properties of oceanic lithosphere, represents one of the major mechanisms driving mass exchange between the mantle and the Earth's surface, and is central to current origin of life hypotheses as well as the search for microbial life on the icy moons of Jupiter and Saturn. In spite of increasing interest in the serpentinization process by researchers in diverse fields, the rates of serpentinization and the controlling factors are poorly understood. Here we use a novel in situ experimental method involving olivine micro-reactors and show that the rate of serpentinization is strongly controlled by the salinity (water activity) of the reacting fluid and demonstrate that the rate of serpentinization of olivine slows down as salinity increases and HO activity decreases.
地幔岩石的水热蚀变（称为蛇纹石化）发生在从大洋中脊延伸到俯冲带的海底环境中。蛇纹石化影响了海洋岩石圈的物理和化学性质，是地幔与地球表面之间物质交换的主要机制之一，也是当前生命起源假说以及在木星和土星的冰卫星上寻找微生物生命的核心。尽管不同领域的研究人员对蛇纹石化过程的兴趣日益增加，但蛇纹石化的速度和控制因素仍了解甚少。在这里，我们使用一种涉及橄榄石微反应器的新的原位实验方法，表明蛇纹石化的速度强烈受反应流体盐度（水活度）的控制，并证明橄榄石蛇纹石化的速度随着盐度的增加和 HO 活度的降低而减慢。
