On rocky planets such as Earth and Mars the serpentinization of olivine in ultramafic crust produces hydrogen that can act as a potential energy source for life. Direct evidence of fluid–rock interaction on Mars comes from iddingsite alteration veins found in martian meteorites. In the Yamato 000593 meteorite, putative biosignatures have been reported from altered olivines in the form of microtextures and associated organic material that have been compared to tubular bioalteration textures found in terrestrial sub‐seafloor volcanic rocks. Here, we use a suite of correlative, high‐sensitivity, in situ chemical, and morphological analyses to characterize and re‐evaluate these microalteration textures in Yamato 000593, a clinopyroxenite from the shallow subsurface of Mars. We show that the altered olivine crystals have angular and micro‐brecciated margins and are also highly strained due to impact‐induced fracturing. The shape of the olivine microalteration textures is in no way comparable to microtunnels of inferred biological origin found in terrestrial volcanic glasses and dunites, and rather we argue that the Yamato 000593 microtextures are abiotic in origin. Vein filling iddingsite extends into the olivine microalteration textures and contains amorphous organic carbon occurring as bands and sub‐spherical concentrations <300 nm across. We propose that a martian impact event produced the micro‐brecciated olivine crystal margins that reacted with subsurface hydrothermal fluids to form iddingsite containing organic carbon derived from abiotic sources. These new data have implications for how we might seek potential biosignatures in ultramafic rocks and impact craters on both Mars and Earth.

中文翻译：

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批判性地测试大和000593陨石-地球生物学的意义中的橄榄石承载的假定火星生物特征。

在地球和火星等岩石行星上，超镁铁质地壳中橄榄石的蛇纹石化产生氢，氢可作为生命的潜在能源。火星上流体与岩石相互作用的直接证据来自火星陨石中发现的边蚀变蚀点。在大和000593陨石中，据报道，经过改变的橄榄石具有微观纹理和相关的有机物质形式，并与陆上海底火山岩中发现的管状生物蚀变质地相比较，具有假定的生物特征。在这里，我们使用一套相关的，高灵敏度的原位化学和形态学分析来表征和重新评估大和000593（一种来自火星浅地下的斜辉石）中的微蚀变质构。我们发现，改变后的橄榄石晶体具有棱角和微尖晶石状的边缘，并且由于冲击诱发的破裂而也高度应变。橄榄石微蚀变质构的形状绝不能与陆地火山玻璃和杜尼岩中发现的推断生物成因的微隧道相提并论，相反，我们认为大和000593微纹理起源于非生物。静脉充填的填充物延伸到橄榄石微蚀变纹理中，并包含无定形有机碳，这些有机碳以谱带和低于300 nm的亚球形浓度出现。我们认为，火星撞击事件产生了微角砾化的橄榄石晶体边缘，这些边缘与地下热液流体反应形成了包含非生物来源有机碳的iddingsite。