In-situ preservation of nitrogen-bearing organics in Noachian Martian carbonates
In-situ preservation of nitrogen-bearing organics in Noachian Martian carbonates
复制标题
诺亚纪火星碳酸盐中含氮有机物的原位保存
DOI：
10.1038/s41467-020-15931-4
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发表时间：
2020
影响因子：
16.6
通讯作者：
Kobayashi Atsuko
中科院分区：
文献类型：
--
作者：
Koike Mizuho;Nakada Ryoichi;Kajitani Iori;Usui Tomohiro;Tamenori Yusuke;Sugahara Haruna;Kobayashi Atsuko
了解火星上有机物质的起源是现代行星科学的一个重大问题。最近对火星沉积岩的机器人探测和对火星陨石的实验室分析都报告了可信的本土有机成分。然而，人们对它们的起源、进化和保存知之甚少。在这里，我们报告说，40亿岁（Ga）的火星陨石，艾伦山84001碳酸盐，保存本地含氮（N）的有机物，通过开发一种新的技术，高空间分辨率原位氮化学形态。这些有机物质是在当地合成的，或在诺亚纪时期在火星上通过陨石运送。碳酸盐，来自火星近地表含水流体的蚀变矿物，在漫长的地质时期内捕获并保持有机物质的完整性。这种含氮化合物的存在需要非生物或可能生物的氮固定和氨储存，这表明早期火星的氧化环境比今天少。
Understanding the origin of organic material on Mars is a major issue in modern planetary science. Recent robotic exploration of Martian sedimentary rocks and laboratory analyses of Martian meteorites have both reported plausible indigenous organic components. However, little is known about their origin, evolution, and preservation. Here we report that 4-billion-year-old (Ga) carbonates in Martian meteorite, Allan Hills 84001, preserve indigenous nitrogen(N)-bearing organics by developing a new technique for high-spatial resolution in situ N-chemical speciation. The organic materials were synthesized locally and/or delivered meteoritically on Mars during Noachian age. The carbonates, alteration minerals from the Martian near-surface aqueous fluid, trapped and kept the organic materials intact over long geological times. This presence of N-bearing compounds requires abiotic or possibly biotic N-fixation and ammonia storage, suggesting that early Mars had a less oxidizing environment than today.