Investigating the organic record of early Mars

西北非洲(NWA)7034和成对的石头是独特的火星陨石，为我们提供了第一个也是唯一一个火星表面表层的样本。这些样品包含各种与撞击有关的岩浆碎屑和沉积碎屑，最早可追溯到44亿年前，大约在15亿年前巩固。因此，NWA7034陨石家族为我们提供了一扇了解火星几十亿年来地质演化的窗口。NWA7034含有矿物相大分子碳(MMC)包裹体；对这些包裹体的初步观察表明，它们可能与在其他玄武岩火星陨石中观察到的非生物成因MMC类似。然而，NWA7034包含了44亿年前火星(亚)表面条件和成分的记录，当时火星很可能是一个宜居世界，因此有必要对其有机物质清单进行彻底调查，以评估其起源。该项目将使用广泛的分析工具来研究NWA7034家族火星陨石的有机记录，包括大量分析和技术，如共聚焦和扫描电子显微镜、光谱(FTIR、拉曼)、(PYR)-GC-MS、核磁共振、无机(LA-ICPMS、NanoSIMS)质谱学和X射线微纳层析。因此，该项目提供了一个接受广泛技术培训的绝佳机会，旨在更清楚地了解火星早期的有机记录。这种综合方法对于尽可能彻底地描述当时在火星上产生的有机化合物的范围，并调查它们的可能来源至关重要。这也需要研究陆地类似物；通过将这些技术应用于已知的记录早期陆地生命的沉积岩(例如，英国托里多尼亚超群的化石层位和南非巴伯顿绿岩带的沉积物)，我们可以确定支持生物起源的关键标志，并评估长期埋藏的有机物的保存潜力。

Northwest Africa (NWA) 7034 and paired stones are unique martian meteorites that provide us with our first and only samples of the martian surface regolith. These samples contain a variety of magmatic, impact-related, and sedimentary clasts as old as ca. 4.4 billion years old that were consolidated sometime around 1.5 billion years ago. The NWA 7034 clan of meteorites thus provides us with a window into the geological evolution of Mars over several billion years. NWA 7034 contains macromolecular carbon (MMC) inclusions in mineral phases; preliminary observations of these inclusions suggest they might have a similar origin than abiogenic MMC observed in other basaltic martian meteorites. However the fact that NWA 7034 contains a record of martian (sub)surface conditions and components from 4.4 billion years ago, at a time when Mars was likely a habitable world, warrants a thorough investigation of its organic material inventory to assess its origins.This project will investigate the organic record of martian meteorites from the NWA 7034 family using a wide array of analytical facilities, including bulk analysis and techniques such as confocal and scanning electron microscopy, spectroscopy (FTIR, Raman), (pyr)-GC-MS, NMR, inorganic (LA-ICP-MS, NanoSIMS) mass spectrometry, and X-ray micro- and nanotomography. This project thus provides a great opportunity to receive training in a wide range of techniques aimed at developing a clearer understanding of the organic record of the early Mars epoch.Such a combined approach is crucial to characterise as thoroughly as possible the range of organic compounds produced on Mars at that time, and investigate their likely origin. This also requires studying terrestrial analogues; by applying these techniques to sedimentary rocks known to record early terrestrial life (e.g., fossil-bearing horizons in the Torridonian Supergroup, UK and sediments from the Barberton Greenstone Belt, South Africa), we can identify key markers supporting biogenicity, and assess the preservation potential of organics that have undergone burial for prolonged periods of time.