High resolution electron microscopy (UltraSTEM) of the most primitive organic materials in chondrite parent bodies and comets - Formation and evolution of the organic inventory of early Earth.

球粒陨石母体和彗星中最原始有机材料的高分辨率电子显微镜 (UltraSTEM) - 早期地球有机库存的形成和演化。

• 批准号: 276966992
• 负责人: Dr. Christian Vollmer
• 金额: --
• 依托单位: Section Population Biology
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/276966992?language=en
• 关键词: resolution; electron; microscopy; UltraSTEM; most

Carbonaceous materials were a widespread constituent of the early solar system and hence part of the initial organic inventory of the terrestrial planets. These materials are today preserved in the most primitive carbonaceous chondrites or interplanetary dust particles (IDPs) originating from comets and have not been overprinted by prolonged thermal metamorphism. A tiny fraction of this carbonaceous matter carries fingerprints of low temperature fractionation reactions as isotope enrichments in, e.g., 15N or D. These isotopically anomalous carbonaceous grains have therefore recorded processes in the cold parent molecular cloud of our solar system or the outer reaches of the young solar nebula. Investigations on these grains are therefore key to unravel the evolution of the most primitive organic compounds that were incorporated into the solar system and therefore finally also into the terrestrial planets and the Earth. As Earth has probably lost most volatiles during differentiation or the moon-forming impact, a late addition of organic matter by asteroids or comets is of crucial interest here. In this project, we will investigate these primitive organic materials by an aberration-corrected scanning transmission electron microscope (UltraSTEM) that is exceptionally suited to study these beam-sensitive grains owing to its low acceleration voltage below the knock-on damage threshold of carbon (~ 80 keV). The unique instrumental setup of this microscope also allows to analyse the electronic bonding configuration of organic matter (e.g., aromatic or aliphatic) with high spatial resolution (~ 0.1 nm) that is not achievable by other methods (e.g., synchrotron spectroscopy). First published results (Vollmer et al. 2014) obtained recently by UltraSTEM analyses on isotopically anomalous organic grains from meteorites and IDPs have shown that fluid-induced parent body reactions can transform fragile pristine organic grains by subtle synthesis processes on a very fine scale. We want to expand on these promising results by analyzing a larger set of isotopically anomalous organic grains from diverse primitive meteorites and cometary samples to search for further evidence of these fluid reactions and to build up a catalogue of the most primitive organic compounds in different parent bodies. These investigations will help to understand the evolution of organic matter in the early solar nebula to more complex molecules important for the origin of life on early Earth.

碳质物质是早期太阳系中广泛存在的组成部分，因此也是类地行星最初的有机物质清单的一部分。这些物质今天保存在最原始的碳质陨石或来自彗星的行星际尘埃颗粒（IDP）中，并没有被长期的热变质作用所覆盖。这种碳质物质的一小部分携带低温分馏反应的指纹，作为同位素富集，例如，15 N或D.因此，这些同位素异常的碳质颗粒记录了我们太阳系的冷母分子云或年轻太阳星云外部的过程。因此，对这些颗粒的研究是解开最原始有机化合物进化的关键，这些化合物被纳入太阳系，因此最终也进入类地行星和地球。由于地球可能在分化或月球形成的影响中失去了大部分挥发物，小行星或彗星后期添加的有机物质在这里至关重要。在这个项目中，我们将通过像差校正扫描透射电子显微镜（UltraSTEM）研究这些原始有机材料，该显微镜非常适合研究这些束敏感颗粒，因为它的加速电压低于碳的撞击损伤阈值（~ 80 keV）。该显微镜的独特仪器设置还允许分析有机物质的电子键合构型（例如，芳香族或脂肪族）的高空间分辨率（~ 0.1nm），这是其它方法无法实现的（例如，同步加速器光谱学）。最近通过对陨石和IDP中同位素异常有机颗粒进行UltraSTEM分析获得的首次发表的结果（Vollmer et al. 2014）表明，流体诱导的母体反应可以通过非常精细的精细合成过程改变脆弱的原始有机颗粒。我们希望通过分析来自不同原始陨石和彗星样品的大量同位素异常有机颗粒来扩展这些有希望的结果，以寻找这些流体反应的进一步证据，并建立一个不同母体中最原始有机化合物的目录。这些调查将有助于了解早期太阳星云中的有机物质演变为对早期地球生命起源至关重要的更复杂分子。

项目成果

PRESERVATION OF IMPACT DERIVED METALLIC SPHERULES WITHIN IMPACTITE VESICLES

冲击囊泡内冲击衍生金属球粒的保存

• DOI: 10.1111/maps.12934
• 发表时间: 2017
• 期刊: Meteoritics & Planetary Science
• 影响因子: 2.2
• 作者: Vollmer C;Leitner J;Busemann H;Spring N;Ramasse Q. M;Kepaptsoglou D.;Hoppe P.
• 通讯作者: Hoppe P.

Challenges and Applications of High Spatial and Energy Resolution EELS for Mapping Functional Chemistry in Beam-Sensitive Materials at Low Acceleration Voltages

高空间和能量分辨率 EELS 在低加速电压下绘制光束敏感材料功能化学的挑战和应用

• DOI: 10.1017/s1431927619003131
• 发表时间: 2019
• 期刊: Microscopy and Microanalysis
• 影响因子: 2.8
• 作者: Ramasse Q. M;Kepaptsoglou D;Vollmer C;Hage F;Abellan P.;Leitner J.
• 通讯作者: Leitner J.

An isotopic, elemental and structural study of silicon nitride from enstatite chondrites

• DOI: 10.1016/j.gca.2018.05.025
• 发表时间: 2018-08
• 期刊: Geochimica et Cosmochimica Acta
• 影响因子: 5
• 作者: J. Leitner;C. Vollmer;T. Henkel;U. Ott;P. Hoppe

Isotopic compositions, nitrogen functional chemistry, and low‐loss electron spectroscopy of complex organic aggregates at the nanometer scale in the carbonaceous chondrite Renazzo

碳质球粒陨石 Renazzo 纳米级复杂有机聚集体的同位素组成、氮功能化学和低损耗电子能谱

• DOI: 10.1111/maps.13389
• 发表时间: 2020
• 期刊: Meteoritics & Planetary Science
• 影响因子: 2.2
• 作者: Vollmer C;Leitner J;Kepaptsoglou D;Ramasse Q. M;Busemann H.;Hoppe P.
• 通讯作者: Hoppe P.