Spectroscopic characterization of samples from different environments in a Volcano-Glacial region in Iceland: Implications for in situ planetary exploration
Spectroscopic characterization of samples from different environments in a Volcano-Glacial region in Iceland: Implications for in situ planetary exploration
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DOI：
10.1016/j.saa.2021.120205
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发表时间：
2021-07-28
影响因子：
4.4
通讯作者：
Samuels, Alan C.
中科院分区：
文献类型：
--
作者：
Bower, Dina M.;Yang, Clayton S. C.;Samuels, Alan C.
拉曼光谱和激光诱导击穿光谱（LIBS）是互补的技术，可以一起提供地质环境的综合表征。对于在其他行星上限制获取目标材料的着陆任务来说，辨别生命和可居住性的特征可能是令人生畏的，特别是在含有生命组成部分的有机化合物的保存有限的情况下。任何天然样品的光谱测量所面临的主要挑战是复杂的光谱，通常包含多个成分的特征，特别是在由几种矿物组成的岩石中，表面被微生物定植。本研究的目的是使用拉曼光谱和LIBS的组合，以辨别不同的环境制度的基础上，在岩石和沉积物中的矿物和生物分子的识别。冰岛是一个陆地火山-冰川位置，提供了一系列类似行星的环境，包括火山活动区，广泛的熔岩场，地热泉，以及与岩石和冰冷的行星体相关的大片冰雪覆盖的地形。我们结合了便携式维斯（532 nm）和NIR（785 nm）拉曼光谱、维斯显微拉曼光谱绘图和UV/维斯/NIR（200 - 1000 nm）和中红外（5.6 - 10 μ m，1785 - 1000 cm（-1））激光诱导击穿光谱（LIBS），以表征矿物组合，水合组分，研究人员对从冰岛火山活跃的Kverkfjoll-Vatnajokull地区的三个主要地点收集的岩石和沉积物样本中的生物分子和生物分子进行了分析：Hveragil地热流中的玄武岩和以玄武岩为主体的碳酸盐外壳、Kverkfjoll Vatnajokull冰川底部的火山沉积物以及附近Holuhraun熔岩场的熔岩。通过我们的技术组合，我们能够识别每个样本集的典型主要矿物多型，以及所有样本中地衣群落的典型生物分子的多样性。我们观察到的熔岩与火山沉积物的显微拉曼光谱映射相比，建议不同的形成途径：熔岩碎屑自生，沉积碎屑可能与微生物风化形成。仅在碳酸盐样品中检测到的锰氧化物似乎有两种可能的形成途径，要么是河流风化，要么是微生物风化，要么是两者兼而有之。即使我们有能力在所有样本中检测到多种多样的生物分子和矿物质，但根据本研究所做的有限测量，每组样本之间的差异也不足以区分不同的环境。(C)2021爱思唯尔有限公司版权所有。
Raman spectroscopy and laser induced breakdown spectroscopy (LIBS) are complementary techniques that together can provide a comprehensive characterization of geologic environments. For landed missions with constrained access to target materials on other planetary bodies, discerning signatures of life and habitability can be daunting, particularly where the preservation of organic compounds that contain the building blocks of life is limited. The main challenge facing any spectroscopy measurements of natural samples is the complicated spectra that often contain signatures for multiple components, particularly in rocks that are composed of several minerals with surfaces colonized by microbes. The goal of this study was to use the combination of Raman spectroscopy and LIBS to discern different environmental regimes based on the identification of minerals and biomolecules in rocks and sediments. Iceland is a terrestrial volcano-glacial location that offers a range of planetary analog environments, including volcanically active regions, extensive lava fields, geothermal springs, and large swaths of ice-covered terrain that are relevant to both rocky and icy planetary bodies. We combined portable VIS (532 nm) and NIR (785 nm) Raman spectroscopy, VIS micro-Raman spectroscopic mapping, and UV/VIS/NIR (200 - 1000 nm) and Mid-IR (5.6 - 10 mu m, 1785 - 1000 cm(-1)) laser induced breakdown spectroscopy (LIBS) to characterize the mineral assemblages, hydrated components, and biomolecules in rock and sediment samples collected from three main sites in the volcanically active Kverkfjoll-Vatnajokull region of Iceland: basalt and basalt-hosted carbonate rind from Hveragil geothermal stream, volcanic sediments from the base of Vatnajokull glacier at Kverkfjoll, and lava from the nearby Holuhraun lava field. With our combination of techniques, we were able to identify major mineral polytypes typical for each sample set, as well as a large diversity of biomolecules typical for lichen communities across all samples. The anatase we observed using micro-Raman spectroscopic mapping of the lava compared with the volcanic sediment suggested different formation pathways: lava anatase formed authigenically, sediment anatase could have formed in association with microbial weathering. Mn-oxide, only detected in the carbonate samples, seems to have two possible formation pathways, either by fluvial or microbial weathering or both. Even with our ability to detect a wide diversity of biomolecules and minerals in all of the samples, there was not enough variation between each set to distinguish different environments based on the limited measurements done for this study. (C) 2021 Elsevier B.V. All rights reserved.