Visible-infrared spectroscopy of ungrouped and rare meteorites brings further constraints on meteorite-asteroid connections
Visible-infrared spectroscopy of ungrouped and rare meteorites brings further constraints on meteorite-asteroid connections
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未分组和稀有陨石的可见红外光谱进一步限制了陨石与小行星的联系
DOI：
10.1016/j.icarus.2021.114393
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发表时间：
2021
期刊：
影响因子：
3.2
通讯作者：
J. Eschrig
中科院分区：
文献类型：
--
作者：
L. K. Ruggiu;P. Beck;J. Gattacceca;J. Eschrig
小行星的组成为太阳系的形成和演化提供了重要的见解。尽管光谱调查和航天器任务提供了有关小天体的信息，但许多重要的分析只能在地面实验室中进行。陨石是我们外星物质样本的主要来源。确定这些陨石的来源小行星对于在内太阳系更广泛的背景下解释它们的分析至关重要。目前，我们的陨石收藏中的母体总数估计约为 150 个母体，其中 50 个母体是研究很少的未分组球粒陨石。因此，将未分组的陨石与其母体联系起来对于显着增加我们对小行星的了解至关重要。为此，对 25 个未分组的球粒陨石和稀有陨石群进行了岩相学研究，根据结构、矿物学以及水相和热母体处理将其分为 6 个岩相组。然后，我们获取了这 25 颗陨石的可见光-近红外 (VIS-NIR) 反射光谱数据，以便将它们与小行星的地面望远镜观测进行比较。陨石的反射光谱是在粉末样品上获得的，就像此类研究中通常所做的那样，但也在原始样品和抛光切片上获得。由于小行星表面比细粒风化层（例如小行星 (101955) Bennu）更复杂，特别是近地小行星，因此使用原始样本是研究母体的必要补充。我们的结果表明，样品制备会影响光谱的形状，从而影响小行星光谱匹配，特别是对于碳质球粒陨石。总体而言，最初定义的岩相组与反射光谱组一致，只有少数例外。然后将陨石光谱与小行星分类学的参考端元光谱进行比较。我们使用光谱形状的定性匹配以及光谱参数（带位置、带深度以及 1 和 2 μm 处的斜率）的定量比较，将 25 颗研究的陨石与小行星类型进行匹配。我们定义了一些所研究的未分组球粒陨石和之前提出的没有陨石联系的小行星类型之间的联系，例如一些非常原始的 3.00 型未分组球粒陨石与 B 型或 Cg 型小行星。我们还将变质的未分组碳质球粒陨石与S复合体小行星进行了匹配，表明该复合体不仅由普通球粒陨石或原始无球粒陨石组成，如先前所确定的，而且还可能含有碳质球粒陨石。相反，一些未分组的球粒陨石无法与任何已知的小行星类型相匹配，这表明这些是来自尚未识别的小行星类型的潜在样本。
The composition of asteroids gives crucial insights into the formation and evolution of the Solar System. Although spectral surveys and spacecraft missions provide information on small bodies, many important analyses can only be performed in terrestrial laboratories. Meteorites represent our main source of samples of extraterrestrial material. Determining the source asteroids of these meteorites is crucial to interpret their analyses in the broader context of the inner Solar System. For now, the total number of parent bodies represented in our meteorites collection is estimated to about 150 parent bodies, of which 50 parent bodies represented by the poorly studied ungrouped chondrites. Linking ungrouped meteorites to their parent bodies is thus crucial to significantly increase our knowledge of asteroids. To this end, the petrography of 25 ungrouped chondrites and rare meteorite groups was studied, allowing grouping into 6 petrographic groups based on texture, mineralogy, and aqueous and thermal parent body processing. Then, we acquired visible-near-infrared (VIS-NIR) reflectance spectroscopy data of those 25 meteorites, in order to compare them to ground-based telescopic observations of asteroids. The reflectance spectra of meteorites were obtained on powdered samples, as usually done for such studies, but also on raw samples and polished sections. With asteroids surfaces being more complex than fine-grained regolith (e.g., asteroid (101955) Bennu), in particular near-Earth asteroids, the use of raw samples is a necessary addition for investigating parent bodies. Our results showed that sample preparation influences the shape of the spectra, and thus asteroid spectral matching, especially for carbonaceous chondrites. Overall, the petrographic groups defined initially coincide with reflectance spectral groups, with only few exceptions. The meteorite spectra were then compared with reference end-member spectra of asteroids taxonomy. We matched the 25 studied meteorites to asteroids types, using a qualitative match of the shape of the spectra, as well as a quantitative comparison of spectral parameters (bands positions, bands depths and slopes at 1 and 2 μm). We define links between some of the studied ungrouped chondrites and asteroid types that had no meteorite connection proposed before, such as some very primitive type 3.00 ungrouped chondrites to B-type or Cg-type asteroids. We also matched metamorphosed ungrouped carbonaceous chondrites to S-complex asteroids, suggesting that this complex is not only composed of ordinary chondrites or primitive achondrites, as previously established, but may also host carbonaceous chondrites. Conversely, some ungrouped chondrites could not be matched to any known asteroid type, showing that those are potential samples from yet unidentified asteroid types.
Loongana (CL) 碳质球粒陨石群
影响因子：
5
作者：
Metzler K;Hezel D. C;Barosch J;Wölfer E;Schneider J. M;Berndt J;Stracke A;Gattacceca J;Greenwood R. C;Franchi;Burkhardt C.;Kleine T.
通讯作者：
Kleine T.
影响因子：
5
作者：
Beck, P.;Quirico, E.;Guillot, S.
通讯作者：
Guillot, S.