The recognition of past habitable environments on Mars has increased the urgency to understand biosignature preservation in and characterize analogues of these environments on Earth. In this Review, we examine the detection and interpretation of potential biosignatures preserved in deposits rich in carbonates, silica and clay. Many of the earliest chemical, textural and morphological evidence of life on Earth are found in carbonates and carbonate-hosted phases. Early diagenetic chert within carbonate deposits can exceptionally preserve microbial body fossils, and clay minerals that form in ultramafic terrains can protect organic matter. On Mars, similar deposits older than 3.5 billion years could contain biosignatures or remnants of prebiotic processes that have long been erased from Earth. Terrestrial analogues for the deposition of magnesium carbonate minerals in Jezero crater, Mars, present patterns that can guide the collection of samples with the highest astrobiological potential by the Perseverance rover. Continued characterization of terrestrial analogue sites and rigorous examination of the processes that impact the preservation of isotopic signals, organic compounds, and microbial textures and fossils will advance the interpretation of Martian deposits.

对火星上过去可居住环境的认识增加了了解地球上这些环境类似物的生物特征保存和表征的紧迫性。在这篇综述中，我们研究了对保存在富含碳酸盐、二氧化硅和粘土的矿床中的潜在生物特征的检测和解释。地球上生命的许多最早的化学、结构和形态证据都是在碳酸盐和碳酸盐宿主相中发现的。碳酸盐岩矿床中的早期成岩燧石可以很好地保存微生物体化石，而在超基性地层中形成的粘土矿物可以保护有机质。在火星上，超过 35 亿年的类似沉积物可能包含早已从地球上抹去的生物特征或生命前过程的残余物。火星 Jezero 陨石坑中碳酸镁矿物沉积的陆地类似物所呈现的模式可以指导毅力漫游车收集具有最高天体生物学潜力的样本。对陆地类似地点的持续表征和对影响同位素信号、有机化合物、微生物结构和化石保存的过程的严格检查将推进对火星沉积物的解释。