The old, unique C1 chondrite Flensburg - Insight into the first processes of aqueous alteration, brecciation, and the diversity of water-bearing parent bodies and lithologies
|Author(s)||Bischoff Addi1, Alexander Conel M. O'D2, Barrat Jean-Alix3, Burkhardt Christoph1, Busemann Henner4, Degering Detlev5, Di Rocco Tommaso6, Fischer Meike6, 7, Fockenberg Thomas8, Foustoukos Dionysis, I2, Gattacceca Jerome9, Godinho Jose R. A.10, Harries Dennis11, Heinlein Dieter12, Hellmann Jan L.1, Hertkorn Norbert13, Holm Anja1, Jull A. J. Timothy14, 15, Kerraouch Imene1, King Ashley J.16, 17, Kleine Thorsten1, Koll Dominik18, Lachner Johannes19, Ludwig Thomas20, Merchel Silke19, Mertens Cornelia A. K.4, Morino Precillia4, Neumann Wladimir20, Pack Andreas6, Patzek Markus1, Pavetich Stefan18, Reitze Maximilian P.1, Rufenacht Miriam4, Rugel Georg19, Schmidt Charlotte20, Schmitt-Kopplin Philippe14, 21, Schonbachler Maria4, Trieloff Mario20, Wallner Anton18, 19, Wimmer Karl22, Woelfer Elias1|
|Affiliation(s)||1 : Univ Munster, Inst Planetol, Wilhelm Klemm Str 10, D-48149 Munster, Germany.
2 : Carnegie Inst Sci, Earth & Planets Lab, Washington, DC 20015 USA.
3 : Univ Bretagne Occident, Inst Univ Europeen Mer, Pl Nicolas Copern, F-29280 Plouzane, France.
4 : Swiss Fed Inst Technol, Inst Geochem & Petrol, Clausiusstr 25, CH-8092 Zurich, Switzerland.
5 : Analyt & Entsorgung Rossendorf eV, VKTA Strahlenschutz, Bautzner Landstr 400, D-01328 Dresden, Germany.
6 : Univ Gottingen, Geowissensch Zentrum, Goldschmidtstr 1, D-37077 Gottingen, Germany.
7 : Max Planck Inst Sonnensyst Forsch, Justus von Liebig Weg 3, D-37077 Gottingen, Germany.
8 : Ruhr Univ Bochum, Inst Geol Mineral & Geophys, D-44780 Bochum, Germany.
9 : Aix Marseille Univ, Coll France, CEREGE, INRAE,IRD,CNRS, Aix En Provence, France.
10 : Helmholtz Zentrum Dresden Rossendorf, Helmholtz Inst Freiberg Resource Technol, Chemnitzer Str 40, D-09599 Freiberg, Germany.
11 : Friedrich Schiller Univ Jena, Inst Geowissensch, Carl Zeiss Promenade 10, D-07745 Jena, Germany.
12 : German Fireball Network, Lilienstr 3, D-86156 Augsburg, Germany.
13 : Helmholtz Zentrum Munchen, Analyt BioGeoChem, German Res Ctr Environm Hlth, Ingolstadter Landstr 1, D-85764 Neuherberg, Germany.
14 : Univ Arizona, AMS Lab, 1118 East Fourth St, Tucson, AZ 85721 USA.
15 : Hungarian Acad Sci, Isotope Climatol & Environm Res Ctr ICER, Inst Nucl Res, Bem Ter 18-C, H-4026 Debrecen, Hungary.
16 : Open Univ, Sch Phys Sci, Milton Keynes MK7 6AA, Bucks, England.
17 : Nat Hist Museum, Dept Earth Sci, Cromwell Rd, London SW7 5BD, England.
18 : Australian Natl Univ, Res Sch Phys, Dept Nucl Phys, Canberra, ACT 2601, Australia.
19 : Helmholtz Zentrum Dresden Rossendorf, Bautzner Landstr 400, D-01328 Dresden, Germany.
20 : Heidelberg Univ, Inst Geowissensch, Klaus Tschira Lab Kosmochem, Neuenheimer Feld 234-236, D-69120 Heidelberg, Germany.
21 : Tech Univ Munich, Chair Analyt Food Chem, D-85354 Freising Weihenstephan, Germany.
22 : RiesKraterMuseum, Eugene Shoemaker Pl 1, D-86720 Nordlingen, Germany.
|Source||Geochimica Et Cosmochimica Acta (0016-7037) (Pergamon-elsevier Science Ltd), 2021-01 , Vol. 293 , P. 142-186|
|WOS© Times Cited||6|
|Keyword(s)||C1 chondrite, Carbonaceous chondrite, Aqueous alteration, Carbonates, Early solar system, Oldest carbonates in solar system, Unique chondrite, Ungrouped C chondrite|
On September 12, 2019 at 12:49:48 (UT) a bolide was observed by hundreds of eye-witnesses from the Netherlands, Germany, Belgium, Denmark and the UK. One day later a small meteorite stone was found by accident in Flensburg. The presence of short-lived cosmogenic radionuclides with half-lives as short as 16 days proves the recent exposure of the found object to cosmic rays in space linking it clearly to the bolide event. An exceptionally short exposure time of similar to 5000 years was determined. The 24.5 g stone has a fresh black fusion crust, a low density of <2 g/cm(3), and a magnetic susceptibility of log chi = 4.35 (chi in 10(-9) m(3)/kg). The rock consists of relict chondrules and clusters of sulfide and magnetite grains set in a fine-grained matrix. The most abundant phases are phyllosilicates. Carbonates (similar to 3.9 vol.%) occur as calcites, dolomites, and a Na-rich phase. The relict chondrules (often surrounded by sulfide laths) are free of anhydrous silicates and contain abundant serpentine. Lithic clasts are also surrounded by similar sulfide laths partly intergrown with carbonates. Mn-53-Cr-53 ages of carbonates in Flensburg indicate that brecciation and contemporaneous formation of the pyrrhotite-carbonate intergrowths by hydrothermal activities occurred no later than 4564.6 +/- 1.0 Ma (using the angrite D'Orbigny as the Mn-Cr age anchor). This corresponds to 2.6 +/- 1.0 or 3.4 +/- 1.0 Ma after formation of CAIs, depending on the exact absolute age of CAIs. This is the oldest dated evidence for brecciation and carbonate formation, which likely occurred during parent body growth and incipient heating due to decay of Al-26. In the three oxygen isotope diagram, Flensburg plots at the O-16-rich end of the CM chondrite field and in the transition field to CV-CK-CR chondrites. The mass-dependent Te isotopic composition of Flensburg is slightly different from mean CM chondrites and is most similar to those of the ungrouped C2 chondrite Tagish Lake. On the other hand, Ti-50 and Cr-54 isotope anomalies indicate that Flensburg is similar to CM chondrites, as do the similar to 10 wt.% H2O of the bulk material. Yet, the bulk Zn, Cu, and Pb concentrations are about 30% lower than those of mean CM chondrites. The He, Ne, and Ar isotopes of Flensburg show no solar wind contribution; its trapped noble gas signature is similar to that of CMs with a slightly lower concentration of Ne-20(tr). Based on the bulk H, C, and N elemental abundances and isotopic compositions, Flensburg is unique among chondrites, because it has the lightest bulk H and N isotopic compositions of any type 1 or 2 chondrite investigated so far. Moreover, the number of soluble organic compounds in Flensburg is even lower than that of the brecciated CI chondrite Orgueil. The extraordinary significance of Flensburg is evident from the observation that it represents the oldest chondrite sample in which the contemporaneous episodes of aqueous alteration and brecciation have been preserved. The characterization of a large variety of carbonaceous chondrites with different alteration histories is important for interpreting returned samples from the OSIRIS-REx and Hayabusa 2 missions. (C) 2020 The Authors. Published by Elsevier Ltd.