Fraktionierung der schweren Edelgase und des Stickstoffs in Mars-Meteoriten als Folge terrestrischer und marsianischer Verwitterungsvorgänge

由于陆地和火星风化过程，火星陨石中重惰性气体和氮气的分馏

• 批准号: 18223948
• 负责人: Dr. Susanne Petra Schwenzer
• 金额: --
• 依托单位: Lunar and Planetary Institute
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2006-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/18223948?language=en
• 关键词: Fraktionierung; der; schweren; Edelgase; und

The strongest evidence linking the class of SNC meteorites to Mars is the presence of a gas component (noble gases, nitrogen, CO2) in several of them, which agrees with the composition of the Martian atmosphere (within the uncertainties of the atmospheric measurements by Viking). However, Martian meteorites contain also other gas components in addition to Mars atmosphere. A complication in their study is indicated by the comparison of results for Martian meteorites of differing (terrestrial) provenance (hot and cold desert, fall). Elementally fractionated heavy noble gases were found to be incorporated in meteorites from hot deserts, which makes the interpretation of data from these meteorites difficult. In pilot studies we found an elementally fractionated air (EFA) component showing signatures, which can easily be misinterpreted as Martian interior. We plan - through the analysis of nitrogen and noble gases in terrestrial samples, Martian meteorites and samples weathered in laboratory experiments - to determine abundances and signatures of the EFA component in more detail and to obtain clues regarding the incorporation mechanism. Features similar to EFA (such as a low 84Kr/132Xe when compared to the respective parent atmosphere) are observed in the nakhlites and ALH84001 and are possibly due to similar fractionation processes acting on Mars. Thus our results will allow drawing conclusions regarding the influence of weathering on volatiles in Martian rocks on Mars as well as complications caused by contamination processes on Earth.

将SNC类陨石与火星联系起来的最有力证据是，其中几颗陨石中存在气体成分（惰性气体、氮、二氧化碳），这与火星大气的组成（在维京号大气测量的不确定性范围内）一致。然而，火星陨石除了含有火星大气外，还含有其他气体成分。他们研究的一个复杂之处在于，对不同（陆地）来源的火星陨石（热沙漠和冷沙漠，秋天）的结果进行了比较。在炎热沙漠的陨石中发现了元素分馏的重惰性气体，这使得对这些陨石数据的解释变得困难。在初步研究中，我们发现一种元素分馏空气（EFA）成分显示出特征，这很容易被误解为火星内部。我们计划通过分析地球样品、火星陨石和实验室风化样品中的氮和惰性气体，更详细地确定EFA成分的丰度和特征，并获得有关合并机制的线索。在nakhlite和ALH84001中观测到与EFA相似的特征（例如与各自的母体大气相比，84Kr/132Xe较低），这可能是由于类似的分馏过程在火星上起作用。因此，我们的结果将允许得出关于风化对火星上火星岩石挥发物的影响以及地球上污染过程引起的复杂性的结论。