School of Earth and Space Exploration, Arizona State University, Tempe, Arizona, 85287-6004, USA.
Center for Meteorite Studies, Arizona State University, Tempe, AZ, 85287-6004, USA.
Sci Rep. 2018 Aug 17;8(1):12385. doi: 10.1038/s41598-018-30807-w.
Determining the hydrogen isotopic compositions and HO contents of meteorites and their components is important for addressing key cosmochemical questions about the abundance and source(s) of water in planetary bodies. However, deconvolving the effects of terrestrial contamination from the indigenous hydrogen isotopic compositions of these extraterrestrial materials is not trivial, because chondrites and some achondrites show only small deviations from terrestrial values such that even minor contamination can mask the indigenous values. Here we assess the effects of terrestrial weathering and contamination on the hydrogen isotope ratios and HO contents of meteoritic minerals through monitored terrestrial weathering of Tissint, a recent Martian fall. Our findings reveal the rapidity with which this weathering affects nominally anhydrous phases in extraterrestrial materials, which illustrates the necessity of sampling the interiors of even relatively fresh meteorite falls and underlines the importance of sample return missions.
确定陨石及其成分的氢同位素组成和 HO 含量对于解决行星体中水的丰度和来源等关键宇宙化学问题非常重要。然而，要从这些外星物质的本土氢同位素组成中解卷积出地球污染的影响并不容易，因为球粒陨石和一些无球粒陨石只显示出与地球值的微小偏差，以至于即使是少量的污染也可能掩盖本土值。在这里，我们通过对最近一次火星坠落的 Tissint 的监测地球风化，评估了地球风化和污染对陨石矿物的氢同位素比值和 HO 含量的影响。我们的研究结果揭示了这种风化对行星体中无水相的迅速影响，这说明了即使是相对较新的陨石坠落，也有必要对内部进行取样，并强调了样本返回任务的重要性。
