^1,2Dennis HARRIES,³Xuchao ZHAO,³Ian FRANCHI
Meteoritics & Planetary Science (in Press) Open Access Link to Article [doi: 10.1111/maps.13980]
¹Department of Analytical Mineralogy, Institute of Geoscience, Friedrich Schiller University Jena, Carl-Zeiss-Promenade 10,07745 Jena, Germany
²European Space Resources Innovation Centre, Luxembourg Institute of Science and Technology, 41 rue du Brill, L-4422Belvaux, Luxembourg
³School of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
Published by arrangement with John Wiley & Sons

Hydroxyl defects in nominally anhydrous minerals (NAMs) were potential carriers ofwater in the early Solar System and might have contributed to the accretion of terrestrial water.To better understand this, we have conducted a nanoscale secondary ion mass spectrometrysurvey of water contents in olivine and orthopyroxene from a set of equilibrated ordinarychondrites of the L and LL groups (Baszk ́owka, Bensour, Kheneg Ljouˆad, and Tuxtuac) andseveral ultramafic achondrites (Zakøodzie, Dhofar 125, Northwest Africa [NWA] 4969, NWA6693, and NWA 7317). For calibration, we used terrestrial olivine and orthopyroxene with H2Ocontents determined by Fourier transform infrared. Our 99.7% (~3SD) detection limits are 3.6–5.4 ppmw H2O for olivine and 7.7–10.9 ppmw H2O for orthopyroxene. None of the meteoriticsamples studied consistently shows water contents above the detection limits. A few exceptionsslightly above the detection limits are suspected of terrestrial contamination by ferricoxyhydroxides. If the meteorite samples investigated accreted in the presence of small amountsof water ice, the upper limits of water contents provided by our survey suggest that the retentionof hydrogen during thermal metamorphism and differentiation was ineffective. We suggest thatloss occurred through combinations of low internal pressures, high permeability along grainboundaries, and speciation of hydrogen into reduced compounds such as H2and methane,which are less soluble in NAMs than in water.

^1,2Amanda Tosi et al. (>10)
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13976]
¹LABSONDA/IGEO/UFRJ, Instituto de Geociências, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos, 274, Cidade Universitária, 21941-972 Rio de Janeiro, RJ, Brazil
²LABET/MN/UFRJ, Laboratório Extraterrestre, Departamento de Geologia e Paleontologia, Museu Nacional, Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil
Published by arrangement with John Wiley & Sons

On August 19, 2020, at 13:18—UTC, a meteor event ended as a meteorite shower in Santa Filomena, a city in the Pernambuco State, northeast Brazil. The heliocentric orbital parameters resulting from images by cameras of the weather broadcasting system were semimajor axis a = 2.1 ± 0.1 au, eccentricity e = 0.55 ± 0.03, and inclination i = 0.15o ± 0.05. The data identified the body as an Apollo object, an Earth-crossing object with a pericenter interior to the Earth’s orbit. The chemical, mineralogical, and petrological evaluations, as well as the physical analysis, followed several traditional techniques. The meteorite was identified as a H5-6 S4 W0 ordinary chondrite genomict breccia. The large amount of metal in the meteorite made a metallographic evaluation based on the opaque phases possible. The monocrystalline kamacite crystals suggest a higher petrological type and the distorted Neumann lines imply at least two different shock events. The absence of the plessite phase shows that the meteorite did not reach the highest shock levels S5 and S6. The well-defined polycrystalline taenite is indicative of petrologic types 4 and 5 due to the conserved internal tetrataenite rim at the boundaries. The presence of polycrystalline taenites and the characteristics of the Agrell Effect suggest that the Santa Filomena meteorite did not reheat above 700°C. The absence of martensite confirms reheating temperatures <800°C and a slow cooling rate. The Ni contents and sizes of the zoned taenite particles indicate a slow cooling rate ranging from 1 to 10 K Myr−1.