title: Fluid-induced organic synthesis in the solar nebula recorded in extraterrestrial dust from meteorites.
abstract: 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.
authors.affiliation: Institut für Mineralogie, Universität Münster, D-48149 Münster, Germany; christian.vollmer@wwu.de.
authors.forename: Christian
authors.initials: C
authors.lastname: Vollmer
authors.affiliation: SuperSTEM Laboratory, Science & Technology Facilities Council Daresbury Laboratories, Daresbury WA4 4AD, United Kingdom;
authors.forename: Demie
authors.initials: D
authors.lastname: Kepaptsoglou
authors.affiliation: Abteilung Partikelchemie, Max-Planck-Institut für Chemie, D-55128 Mainz, Germany;
authors.forename: Jan
authors.initials: J
authors.lastname: Leitner
authors.affiliation: School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester M13 9PL, United Kingdom; and.
authors.forename: Henner
authors.initials: H
authors.lastname: Busemann
authors.affiliation: School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester M13 9PL, United Kingdom; and.
authors.forename: Nicole H
authors.initials: NH
authors.lastname: Spring
authors.affiliation: SuperSTEM Laboratory, Science & Technology Facilities Council Daresbury Laboratories, Daresbury WA4 4AD, United Kingdom;
authors.forename: Quentin M
authors.initials: QM
authors.lastname: Ramasse
authors.affiliation: Abteilung Partikelchemie, Max-Planck-Institut für Chemie, D-55128 Mainz, Germany;
authors.forename: Peter
authors.initials: P
authors.lastname: Hoppe
authors.affiliation: Department of Terrestrial Magnetism, Carnegie Institution of Washington, NW, Washington, DC 20015.
authors.forename: Larry R
authors.initials: LR
authors.lastname: Nittler
mesh_terms: D060326:Chemistry Techniques, Synthetic; D019443:Cosmic Dust / Q000032:analysis*; D019110:Meteoroids; D046529:Microscopy, Electron, Transmission; D016082:Solar System; D013057:Spectrum Analysis
chemical_list: D019443:Cosmic Dust
keywords: comets; meteorites; organic matter; solar nebula; transmission electron microscopy