Old Dominion University, Department of Ocean and Earth Sciences, Norfolk, Virginia, USA.
Astrobiology. 2021 Jul;21(7):866-892. doi: 10.1089/ast.2021.0011. Epub 2021 May 25.
Abundant and well-preserved fossil microbenthos occurs in siliciclastic deposits of all Earth ages, from the early Archean to today. Studies in modern settings show how microbenthos responds to sediment dynamics by baffling and trapping, binding, biostabilization, and growth. Results of this microbial-sediment interaction are microbially induced sedimentary structures (MISS). Successful prospection for rich MISS occurrences in the terrestrial lithological record requires unraveling genesis and taphonomy of MISS, both of which are defined only by a narrow range of specific conditions. These conditions have to coincide with high detectability which is a function of outcrop quality, bedding character, and rock type. Assertions on biogenicity of MISS morphologies must be based on the presence of microbially induced sedimentary textures (MIST), which are MISS-internal textures comprising replacement minerals arranged into microscopic biological morphologies, ancient carbonaceous matter, trace fossils, and geochemical signals. MISS serve as possible templates for the decryption of ancient life-processes on Mars. This article closes with a perspective on selected deposits and ancient environments in Meridiani Planum, Gale Crater, and Jezero Crater, Mars, regarding their potential for MISS occurrences. The earlier hypothesis of structures on Mars as potentially being MISS is revised.
大量保存完好的化石微生物群落在所有地质时代的硅质碎屑沉积物中都有出现，从早期的太古代到现在。现代环境的研究表明，微生物群如何通过阻挡和捕获、结合、生物稳定化和生长来响应沉积物动力学。这种微生物-沉积物相互作用的结果是微生物诱导的沉积构造（MISS）。要成功寻找陆地岩石记录中丰富的 MISS 发生，需要阐明 MISS 的成因和埋藏学，这两者都只被特定条件的窄范围所定义。这些条件必须与高可探测性相吻合，而高可探测性是露头质量、层理特征和岩石类型的函数。对 MISS 形态的生物成因性的断言必须基于微生物诱导的沉积结构（MIST）的存在，MIST 是 MISS 内部的结构，包括排列成微观生物形态的替代矿物、古老的含碳物质、痕迹化石和地球化学信号。MISS 可以作为解密火星古代生命过程的可能模板。本文最后展望了火星子午线平原、盖尔陨石坑和杰泽罗陨石坑中选定的矿床和古代环境，探讨了它们可能存在 MISS 的情况。对火星上的结构可能是 MISS 的早期假设进行了修正。
