Dominik C. Hezel^a, Markus Harak^b, Guy Libourel^c
Chemie der Erde (in Press) Link to Article [https://doi.org/10.1016/j.chemer.2017.05.003]
^aUniversity of Cologne, Department of Geology and Mineralogy, Zülpicher Str. 49b, 50674, Köln, Germany
^bNatural History Museum, Department of Mineralogy, Cromwell Road, SW7 5BD, London, UK
^cLaboratoire Lagrange, UMR7293, Université de la Côte d’Azur, CNRS, Observatoire de la Côte d’Azur, F-06304, Nice Cedex 4, France
Copyright Elsevier

Chondrules and matrix are the major components of chondritic meteorites and represent a significant evolutionary step in planet formation. The formation and evolution of chondrules and matrix and, in particular, the mechanics of chondrule formation remain the biggest unsolved challenge in meteoritics. A large number of studies of these major components not only helped to understand these in ever greater detail, but also produced a remarkably large body of data. Studying all available data has become known as ‹big data› analyses and promises deep insights – in this case – to chondrule and matrix formation and relationships. Looking at all data may also allow one to better understand the mechanism of chondrule formation or, equally important, what information we might be missing to identify this process. A database of all available chondrule and matrix data further provides an overview and quick visualisation, which will not only help to solve actual problems, but also enable students and future researchers to quickly access and understand all we know about these components. We collected all available data on elemental bulk chondrule and matrix compositions in a database that we call ChondriteDB. The database also contains petrographic and petrologic information on chondrules. Currently, ChondriteDB contains about 2388 chondrule and 1064 matrix data from 70 different publications and 161 different chondrites. Future iterations of ChondriteDB will include isotope data and information on other chondrite components. Data quality is of critical importance. However, as we discuss, quality is not an objective category, but a subjective judgement. Quantifiable data acquisition categories are required that allow selecting the appropriate data from a database in the context of a given research problem. We provide a comprehensive overview on the contents of ChondriteDB. The database is available as an Excel file upon request from the senior author of this paper, or can be accessed through MetBase.

Laura Schaefer¹ and Bruce Fegley Jr.^2,3
Astrophysical Journal 843, 120 Link to Article [https://doi.org/10.3847/1538-4357/aa784f]
¹Arizona State University, School of Earth and Space Exploration, Tempe, AZ 85287, USA
²Planetary Chemistry Laboratory, Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130, USA
³McDonnell Center for the Space Sciences, USA

The Earth and other rocky planets and planetesimals in the solar system formed through the mixing of materials from various radial locations in the solar nebula. This primordial material likely had a range of oxidation states as well as bulk compositions and volatile abundances. We investigate the oxygen fugacity produced by the outgassing of mixtures of solid meteoritic material, which approximate the primitive nebular materials. We find that the gas composition and oxygen fugacity of binary and ternary mixtures of meteoritic materials vary depending on the proportion of reduced versus oxidized material, and also find that mixtures using differentiated materials do not show the same oxygen fugacity trends as those using similarly reduced but undifferentiated materials. We also find that simply mixing the gases produced by individual meteoritic materials together does not correctly reproduce the gas composition or oxygen fugacity of the binary and ternary mixtures. We provide tabulated fits for the oxygen fugacities of all of the individual materials and binary mixtures that we investigate. These values may be useful in planetary formation models, models of volatile transport on planetesimals or meteorite parent bodies, or models of trace element partitioning during metal-silicate fractionation.

G. A. Doschek and H. P. Warren
Astrophysical Journal 844, 52 Link to Article [https://doi.org/10.3847/1538-4357/aa7bea]
Space Science Division, Naval Research Laboratory, Washington, DC 20375, USA

Element abundances in the solar photosphere, chromosphere, transition region, and corona are key parameters for investigating sources of the solar wind and for estimating radiative losses in the quiet corona and in dynamical events such as solar flares. Abundances in the solar corona and photosphere differ from each other depending on the first ionization potential (FIP) of the element. Normally, abundances with FIP values less than about 10 eV are about 3–4 times more abundant in the corona than in the photosphere. However, recently, an inverse FIP effect was found in small regions near sunspots where elements with FIP less than 10 eV are less abundant relative to high FIP elements (eV) than they are in the photosphere. This is similar to fully convective stars with large starspots. The inverse FIP effect is predicted to occur in the vicinity of sunspots/starspots. Up to now, the solar anomalous abundances have only been found in very spatially small areas. In this paper, we show that in the vicinity of sunspots there can be substantially larger areas with abundances that are between coronal and photospheric abundances and sometimes just photospheric abundances. In some cases, the FIP effect tends to shut down near sunspots. We examine several active regions with relatively large sunspots that were observed with the Extreme-ultraviolet Imaging Spectrometer on the Hinodespacecraft in cycle 24.