Yves Marrocchi

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3 Highlights  In situ calcification (aragonite) of a 3.3 Ga microbial biofilm  Calcification probably due to the activities of a photosynthetic consortium of microorganisms within the biofilm including heterotrophic sulphur reducing bacteria  Preservation of the metastable carbonate phase by the organic matrix and secondary silicification  Oldest known(More)
Primitive interplanetary dust is expected to contain the earliest solar system components, including minerals and organic matter. We have recovered, from central Antarctic snow, ultracarbonaceous micrometeorites whose organic matter contains extreme deuterium (D) excesses (10 to 30 times terrestrial values), extending over hundreds of square micrometers. We(More)
Introduction: Apart from [1], the insoluble organic matter (IOM) isolated from meteorites has been mostly studied in car-bonaceous chondrites (CCs) during the last decade. Numerous details were obtained concerning the macromolecular structure or the isotopic composition of the IOM. In the present study, HF-HCl treatments previously improved on carbonaceous(More)
To evaluate the isotopic composition of the solar nebula from which the planets formed, the relation between isotopes measured in the solar wind and on the Sun's surface needs to be known. The Genesis Discovery mission returned independent samples of three types of solar wind produced by different solar processes that provide a check on possible isotopic(More)
Introduction: Most of the organic carbon in Carbonaceous Chondrites (CC) is in the form of Insoluble Organic Matter (IOM). Isotopically, the IOM in CC appears to be highly un-equilibrated: discrete H and N isotopic anomalies-the so-called hotspots-with δ values up to +19400‰ and +1770‰, respectively, are embedded in the bulk IOM, which has average(More)
Introduction: Carbonaceous chondrites contain trapped noble gases that are present in different carriers. The most abundant carrier, known as "planetary"-also referred to as "Q" or "P1" [1]-is formed of carbonaceous material, the nature of which remains ill-defined. It appears to be mainly composed of aromatic moieties linked by short aliphatic chains for(More)
Meteoritic chondrules are submillimeter spherules representing the major constituent of nondifferentiated planetesimals formed in the solar protoplanetary disk. The link between the dynamics of the disk and the origin of chondrules remains enigmatic. Collisions between planetesimals formed at different heliocentric distances were frequent early in the(More)
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