Relationships between organics, water and early stages of aqueous alteration in the pristine CR3.0 chondrite MET 00426

Guillou, C. Le; Brearley, A. J.

doi:10.1016/j.gca.2013.10.024

Cited by 143 publications

(151 citation statements)

References 86 publications

Supporting

Mentioning

139

Contrasting

Order By: Relevance

“…Second, it is possible that Ca or amorphous carbonates were associated with organic matter in the first place, before incorporation into the meteorite parent body, and would then represent a source of indigenous Ca. The association of organic matter with highly soluble Na and Cl has been recently suggested as an indigenous feature of pristine organic matter (28). The essentially anhydrous IDP AK5 grains 8 and 11 also exhibited some Ca in EEL spectra of the organic grains (Fig.…”

Section: Discussionmentioning

confidence: 77%

“…These investigations are important to understand the origins and evolution of complex organic compounds in ancient meteoritic materials that contributed to the organic inventory of early Earth. Such combined studies have so far been performed, e.g., on organic grains in the Tagish Lake meteorite (15,24), IDPs (5,13,25), comet 81P/Wild 2 material (9, 10), insoluble organic matter (IOM) extracted from meteorites (11,26), and matrix regions in Renazzo-type (CR) and Ivuna-type (CI) chondrites (27)(28)(29) all applying only standard TEM techniques. Recently, synchrotron X-ray absorption near-edge structure (XANES) analyses have been performed on these organic grains before further TEM investigations (e.g., refs.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Fluid-induced organic synthesis in the solar nebula recorded in extraterrestrial dust from meteorites

Vollmer

Kepaptsoglou

Leitner³

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Isotopically anomalous carbonaceous grains in extraterrestrial samples represent the most pristine organics that were delivered to the early Earth. Here we report on gentle aberration-corrected scanning transmission electron microscopy investigations of eight 15 N-rich or D-rich organic grains within two carbonaceous Renazzo-type (CR) chondrites and two interplanetary dust particles (IDPs) originating from comets. Organic matter in the IDP samples is less aromatic than that in the CR chondrites, and its functional group chemistry is mainly characterized by C-O bonding and aliphatic C. Organic grains in CR chondrites are associated with carbonates and elemental Ca, which originate either from aqueous fluids or possibly an indigenous organic source. One distinct grain from the CR chondrite NWA 852 exhibits a rim structure only visible in chemical maps. The outer part is nanoglobular in shape, highly aromatic, and enriched in anomalous nitrogen. Functional group chemistry of the inner part is similar to spectra from IDP organic grains and less aromatic with nitrogen below the detection limit. The boundary between these two areas is very sharp. The direct association of both IDP-like organic matter with dominant C-O bonding environments and nanoglobular organics with dominant aromatic and C-N functionality within one unique grain provides for the first time to our knowledge strong evidence for organic synthesis in the early solar system activated by an anomalous nitrogen-containing parent body fluid. solar nebula | organic matter | meteorites | comets | transmission electron microscopy P rimitive extraterrestrial materials, including unmetamorphosed carbonaceous chondrites, chondritic porous interplanetary dust particles (CP-IDPs), carbonaceous Antarctic micrometeorites, and material from comet 81P/Wild 2, contain isotopically anomalous carbonaceous matter typically enriched in D and/or 15 N compared with the Earth and bulk meteorites (1-11). This carbonaceous matter occurs as diffuse material but also in the form of sub-μm-to μm-sized grains that are extremely enriched in D and/or 15 N and therefore stand out in isotopic maps as so-called "hot spots." These hot spots represent good candidates to study ancient organic compounds that may have served as precursors for the prebiotic history of the early Earth. In many, but not all, cases, the isotopic hot spots occur as so-called "nanoglobules," which are observed as hollow or compact carbonaceous sub-μm spheres in a wide range of primitive extraterrestrial samples (e.g., refs. 11-16). The most widely accepted theory for the origins of the anomalies invokes exothermic ion-molecule isotope exchange reactions at very low temperatures (<25 K) in cold interstellar clouds or the outer reaches of the nascent solar nebula (e.g., refs. 6, 7, 17, and 18). A second possible mechanism for the observed 15 N enrichments is N 2 self-shielding, in which optical depth effects lead to isotopeselective photodissociation (19)(20)(21)(22), but the applicability of the N 2 self-shielding m...

show abstract

Section: Discussionmentioning

confidence: 77%

mentioning

confidence: 99%

Fluid-induced organic synthesis in the solar nebula recorded in extraterrestrial dust from meteorites

Vollmer

Kepaptsoglou

Leitner³

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Yet, unlike in Semarkona, phyllosilicates were not found in DOM 08006 matrix (Davidson et al, 2014b), leaving hydrated amorphous material as the most likely additional H-bearing component. If correct, the primitive CO water contents are similar to those of the most primitive CRs , which are also thought to contain hydrated amorphous silicates with approximately 10 wt.% water/OH (Le Guillou and Brearley, 2014;Howard et al, 2015). The origin(s) of the water in the primitive COs has yet to be determined, but may have a combination of indigenous and terrestrial sources.…”

Section: Water In the Cosmentioning

confidence: 83%

A mutli-technique search for the most primitive CO chondrites

Alexander

Greenwood

Bowden

et al. 2018

Geochimica et Cosmochimica Acta

107

View full text Add to dashboard Cite

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. 2 Abstract As part of a study to identify the most primitive COs and to look for weakly altered CMs amongst the COs, we have conducted a multi-technique study of 16 Antarctic meteorites that had been classified as primitive COs. For this study, we have determined:(1) the bulk H, C and N abundances and isotopes, (2) bulk O isotopic compositions, (3) bulk modal mineralogies, and (4) for some selected samples the abundances and compositions of their insoluble organic matter (IOM). Two of the 16 meteorites do appear to be CMs -BUC 10943 seems to be a fairly typical CM, while MIL 090073 has probably been heated. Of the COs, DOM 08006 appears to be the most primitive CO identified to date and is quite distinct from the other members of its pairing group. The other COs fall into two groups that are less primitive than DOM 08006 and ALH 77307, the previously most primitive CO. The first group is composed of members of the DOM 08004 pairing group, except DOM 08006. The second group is composed of meteorites belonging to the MIL 03377 and MIL 07099 pairing groups. These two pairing groups should probably be combined. There is a dichotomy in the bulk O isotopes between the primitive (all Antarctic finds) and the more metamorphosed COs (mostly falls). This dichotomy can only partly be explained by the terrestrial weathering experienced by the primitive Antarctic samples. It seems that the more equilibrated samples interacted to a greater extent with 16 O-poor material, probably water, than the more primitive meteorites.3

show abstract

“…In carbonaceous chondrites, this heterogeneous population of EOM is often found intimately associated with mineral phases such as iron-rich silicates, sulfides and phyllosilicates, which itself are considered fairly reactive with respect to organic compounds. [7] Overall, EOM exhibits much higher molecular compositional variance and complexity than any common terrestrial organic matter that is formed under comparatively mild and uniform, temperate conditions of temperature, redox conditions and light.…”

Section: Introductionmentioning

confidence: 99%

Nontarget analysis of Murchison soluble organic matter by high‐field NMR spectroscopy and FTICR mass spectrometry

Hertkorn

Harir

Schmitt‐Kopplin

2015

Magnetic Reson in Chemistry

View full text Add to dashboard Cite

High-field NMR spectra of Murchison meteorite methanolic extracts revealed primarily aliphatic extraterrestrial organic matter (EOM) with near statistical branching of commonly C(3-5) units separated by heteroatoms and aromatic units. The ratios of CCH, OCH and C(sp2)H units were 89 : 8 : 3, whereas carbon-based aliphatic chain termination was in the order methyl > -COOH > -CH(CH3)COOH. Aliphatic methine carbon was abundant, but its weak NMR signatures were primarily deduced from JRES (J-resolved) NMR spectra. Carbon NMR spectra were dominated by methylene and methyl carbon; strong apodization revealed methine carbon, of which about 20% was aromatic. Extrapolation provided 5-7% aromatic carbon present in Murchison soluble EOM. Compositional heterogeneity in Murchison methanolic extracts was visible in NMR and Fourier transform ion cyclotron (FTICR) mass spectra obtained from a few cubic millimeters of solid Murchison meteorite; increasing sample size enhanced uniformity of NMR spectra. Intrinsic chemical diversity and pH-dependent chemical shift variance contributed to the disparity of NMR spectra. FTICR mass spectra provided distinct clustering of CHO/CHOS and CHNO/CHNOS molecular series and confirmed the prevalence of aliphatic/alicyclic (73%) over single aromatic (21%) and polyaromatic (6%) molecular compositions, suggesting extensive aliphatic substitution of aromatic units as proposed by NMR. Murchison soluble EOM molecules feature a center with enhanced aromatic and heteroatom content, which provides rather diffuse and weak NMR signatures resulting from a huge overall chemical diversity. The periphery of Murchison EOM molecules comprises flexible branched aliphatic chains and aliphatic carboxylic acids. These project on narrow ranges of chemical shift, facilitating observation in one-dimensional and two-dimensional NMR spectra. The conformational entropy provided by these flexible surface moieties facilitates the solubility of EOM.

show abstract

Relationships between organics, water and early stages of aqueous alteration in the pristine CR3.0 chondrite MET 00426

Cited by 143 publications

References 86 publications

Fluid-induced organic synthesis in the solar nebula recorded in extraterrestrial dust from meteorites

Fluid-induced organic synthesis in the solar nebula recorded in extraterrestrial dust from meteorites

A mutli-technique search for the most primitive CO chondrites

Nontarget analysis of Murchison soluble organic matter by high‐field NMR spectroscopy and FTICR mass spectrometry

Contact Info

Product

Resources

About