Olivier Mousis¹, Thomas Ronnet^1,2, and Jonathan I. Lunine³
Astrophysical Journal 875, 9 Link to Article [DOI: 10.3847/1538-4357/ab0a72 ]
¹Aix Marseille Université, CNRS, CNES, LAM, Marseille, France
²Lund Observatory, Department of Astronomy and Theoretical Physics, Lund University, Box 43, SE-221 00 Lund, Sweden
³Department of Astronomy, Cornell University, Ithaca, NY 14853, USA

Argon, krypton, xenon, carbon, nitrogen, sulfur, and phosphorus have all been measured and found to be enriched by a quasi uniform factor in the 2–4 range, compared to their protosolar values, in the atmosphere of Jupiter. To elucidate the origin of these volatile enrichments, we investigate the possibility of an inward drift of particles made of amorphous ice and adsorbed volatiles, and their ability to enrich in heavy elements the gas phase of the protosolar nebula, once they cross the amorphous-to-crystalline ice transition zone, following the original idea formulated by Monga & Desch. To do so, we use a simple accretion disk model coupled to modules depicting the radial evolution of icy particles and vapors, assuming growth, fragmentation, and crystallization of amorphous grains. We show that it is possible to accrete supersolar gas from the nebula onto proto-Jupiter’s core to form its envelope, and allowing it to match the observed volatile enrichments. Our calculations suggest that nebular gas, with a metallicity similar to that measured in Jupiter, can be accreted by its envelope if the planet is formed in the ~0.5–2 Myr time range and in the 0.5–20 au distance range from the Sun, depending on the adopted viscosity parameter of the disk. These values match a wide range of Jupiter’s formation scenarios, including in situ formation and migration/formation models.

¹Chunlai Li et al. (>10)
Nature 569, 378-382 Link to Article [https://doi.org/10.1038/s41586-019-1189-0]
¹Key Laboratory of Lunar and Deep Space Exploration, National Astronomical Observatories, Chinese Academy of Sciences, Beijing, China

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

^1,2,3Anhuai Lu et al. (>10)
Proceedings of the National Academy of Sciences of the United States of America 116, 9741-9746 Link to Article [https://doi.org/10.1073/pnas.1902473116]
¹Beijing Key Laboratory of Mineral Environmental Function, School of Earth and Space Sciences, Peking University, 100871 Beijing, People’s Republic of China
²The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, 100871 Beijing, People’s Republic of China
³The Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring, School of Geosciences and Info-Physics, Central South University, 410083 Changsha, People’s Republic of China

Sunlight drives photosynthesis and associated biological processes, and also influences inorganic processes that shape Earth’s climate and geochemistry. Bacterial solar-to-chemical energy conversion on this planet evolved to use an intricate intracellular process of phototrophy. However, a natural nonbiological counterpart to phototrophy has yet to be recognized. In this work, we reveal the inherent “phototrophic-like” behavior of vast expanses of natural rock/soil surfaces from deserts, red soils, and karst environments, all of which can drive photon-to-electron conversions. Using scanning electron microscopy, transmission electron microscopy, micro-Raman spectroscopy, and X-ray absorption spectroscopy, Fe and Mn (oxyhydr)oxide-rich coatings were found in rock varnishes, as were Fe (oxyhydr)oxides on red soil surfaces and minute amounts of Mn oxides on karst rock surfaces. By directly fabricating a photoelectric detection device on the thin section of a rock varnish sample, we have recorded an in situ photocurrent micromapping of the coatings, which behave as highly sensitive and stable photoelectric systems. Additional measurements of red soil and powder separated from the outermost surface of karst rocks yielded photocurrents that are also sensitive to irradiation. The prominent solar-responsive capability of the phototrophic-like rocks/soils is ascribed to the semiconducting Fe- and Mn (oxyhydr)oxide-mineral coatings. The native semiconducting Fe/Mn-rich coatings may play a role similar, in part, to photosynthetic systems and thus provide a distinctive driving force for redox (bio)geochemistry on Earth’s surfaces.

^1,2Junyue Tang,¹ Shengyuan Jiang,¹Qiquan Quan,¹Jieneng Liang,¹Yi Shen,¹Ye Tian,³Fengpei Yuan
Planetary and Space Science (in Press) Link to Article [https://doi.org/10.1016/j.pss.2019.05.005]
¹State Key Laboratory of Robotics and System, Harbin Institute of Technology, No.92, Xidazhi St., Nangang Dist, Harbin, 150001, PR China
²Department of Civil and Environmental Engineering, Northwestern University, 2145 Sheridan Rd., Evanston, IL, 60208, USA
³Department of Mechanical, Aerospace and Biomedical Engineering, The University of Tennessee, Knoxville, 124 Perkins Hall, Knoxville, TN, 37996, USA

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

¹Didier Gourier et al. (>10)
Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2019.05.009]
¹Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie de Paris (IRCP), F-75005 Paris, France
Copyright Elsevier

Electron paramagnetic resonance (EPR) analysis of carbonaceous, volcanic, tidal sediments from the 3.33 Ga-old Josefsdal Chert (Kromberg Formation, Barberton Greenstone Belt), documents the presence of two types of insoluble organic matter (IOM): (1) IOM similar to that previously found in Archean cherts from numerous other sedimentary rocks in the world and of purported biogenic origin; (2) anomalous IOM localized in a 2 mm-thick sedimentary horizon. Detailed analysis by continuous-wave-EPR and pulse-EPR reveals that IOM in this layer is similar to the insoluble component of the hydrogenated organic matter in carbonaceous chondrites, suggesting that this narrow sedimentary horizon has preserved organic matter of extraterrestrial origin. This conclusion is supported by the presence in this thin layer of another anomalous EPR signal at g = 3 attributed to Ni-Cr-Al ferrite spinel nanoparticles, which are known to form during atmospheric entry of cosmic objects. From this EPR analysis, it was deduced that the anomalous sedimentary layer originates from deposition, in a nearshore environment, of a cloud of tiny dust particles originating from a flux of micrometeorites falling through the oxygen-poor Archean atmosphere.

^1,2,3Wang, Y.,^2,3Hsu, W.,⁴Guan, Y.
Scientific Reports 9, 5727 Link to Article [DOI: 10.1038/s41598-019-42224-8]
¹Key Laboratory of Planetary Sciences, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, 210034, China
²The State Key Laboratory of Lunar and Planetary Science/Space Science Institute, Macau University of Science and Technology, Taipa, China
³CAS Center for Excellence in Comparative Planetology, Purple Mountain Observatory, Nanjing, 210034, China
⁴Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

^1,2Jaramillo, E.A.,³Royle, S.H.,^4,5Claire, M.W.,^1,3Kounaves, S.P.,³Sephton, M.A.
Geophysical Research Letters 46, 3090-3098 Link to Article [DOI: 10.1029/2018GL081335]
¹Department of Chemistry, Tufts University, Medford, MA, United States
²Now at Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
³Department of Earth Science and Engineering, Imperial College London, London, United Kingdom
⁴School of Earth and Environmental Sciences and Centre for Exoplanet Science, University of St. Andrews, Saint Andrews, United Kingdom
⁵Blue Marble Space Institute of Science, Seattle, WA, United States

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

¹N. M. Curran,^1,2K. H. Joy,³J. F. Snape,¹J. F. Pernet‐Fisher,¹J. D. Gilmour,⁴A. A. Nemchin,³M. J. Whitehouse,¹R. Burgess
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13295]

¹School of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester, M13 9PL UK
²NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, Maryland, 20771 USA
³Department of Geosciences, Swedish Museum of Natural History, SE‐104 05 Stockholm, Sweden
⁴Department of Applied Geology, Curtin University, Perth, Western Australia, 6845 Australia
Published by arrangement with John Wiley & Sons

Miller Range (MIL) 13317 is a heterogeneous basalt‐bearing lunar regolith breccia that provides insights into the early magmatic history of the Moon. MIL 13317 is formed from a mixture of material with clasts having an affinity to Apollo ferroan anorthosites and basaltic volcanic rocks. Noble gas data indicate that MIL 13317 was consolidated into a breccia between 2610 ± 780 Ma and 1570 ± 470 Ma where it experienced a complex near‐surface irradiation history for ~835 ± 84 Myr, at an average depth of ~30 cm. The fusion crust has an intermediate composition (Al₂O₃ 15.9 wt%; FeO 12.3 wt%) with an added incompatible trace element (Th 5.4 ppm) chemical component. Taking the fusion crust to be indicative of the bulk sample composition, this implies that MIL 13317 originated from a regolith that is associated with a mare‐highland boundary that is KREEP‐rich (i.e., K, rare earth elements, and P). A comparison of bulk chemical data from MIL 13317 with remote sensing data from the Lunar Prospector orbiter suggests that MIL 13317 likely originated from the northwest region of Oceanus Procellarum, east of Mare Nubium, or at the eastern edge of Mare Frigoris. All these potential source areas are on the near side of the Moon, indicating a close association with the Procellarum KREEP Terrane. Basalt clasts in MIL 13317 are from a very low‐Ti to low‐Ti (between 0.14 and 0.32 wt%) source region. The similar mineral fractionation trends of the different basalt clasts in the sample suggest they are comagmatic in origin. Zircon‐bearing phases and Ca‐phosphate grains in basalt clasts and matrix grains yield ²⁰⁷Pb/²⁰⁶Pb ages between 4344 ± 4 and 4333 ± 5 Ma. These ancient ²⁰⁷Pb/²⁰⁶Pb ages indicate that the meteorite has sampled a range of Pre‐Nectarian volcanic rocks that are poorly represented in the Apollo, Luna, and lunar meteorite collections. As such, MIL 13317 adds to the growing evidence that basaltic volcanic activity on the Moon started as early as ~4340 Ma, before the main period of lunar mare basalt volcanism at ~3850 Ma.

¹Marcos Alberto Rodrigues Vasconcelos,¹Fernanda Farias Rocha,²Alvaro Penteado Crósta,^3,4Kai Wünnemann,³Nicole Güldemeister,²Emilson Pereira Leite,³Júlio César Ferreira,^3,5Wolf Uwe Reimold
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13298]
¹Department of Geophysics, Instituto de Geociências, Universidade Federal da Bahia, Salvador, Brazil
²Instituto de Geociências, Universidade Estadual de Campinas, R. Carlos Gomes 250, 13083‐855 Campinas, Sao Paulo, Brazil
³Museum für Naturkunde—Leibniz‐Institute for Evolution and Biodiversity Science, Invalidenstrasse 43, 10115 Berlin, Germany
⁴Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
⁵Laboratory of Geochronology, Instituto de Geociências, Universidade de Brasília, 10910‐900 Brasília, Federal District, Brazil
Published by arrangement with John Wiley & Sons

We present the outcomes of simulations of the formation of the Vista Alegre impact structure, Paraná Basin, Brazil. The target comprised a thick sequence of volcanic rocks of predominantly basaltic composition of the Serra Geral Formation that had been deposited on top of sedimentary rocks (sandstones) of the Pirambóia/Botucatu formations. The cratering process was modeled using the iSALE shock physics code. Our best‐fit model suggests that (1) the crater was originally ~10 km in size; (2) it was formed in ~115 s by a stony projectile of 1000 m in diameter, for an assumed impact velocity of 12 km s−1; (3) target rocks underwent a peak pressure of ~20 GPa, in agreement with previous petrographic investigations of shock deformation. Furthermore, the model points out that the sedimentary strata below the layer of volcanic rocks were raised by ~650 meters at the central part of the crater, which resulted in the current partial exposure of the sandstones at the surface. The outcomes of our modeling suggest that parameters like cohesion and strength of the target rocks, after shock compression, determined the final morphology of the crater, especially the absence of a topographically prominent central peak. Finally, the results of the numerical modeling are roughly in agreement with gravity data over the structure, in particular with respect to the presence of the uplifted sedimentary strata, which are responsible for a low gravity signature at the center of the structure.

^1,2,3Ji, J.,^1,2Hu, S.,^1,2Lin, Y.,⁴Zhou, Q.,⁴Xiao, Y.
Chinese Science Bulletin (Kexue Tongbao) 64, 579-587 Link to Article [DOI: 10.1360/N972018-00972]
¹Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China
²Key Laboratory of Earth and Planetary Physics, Chinese Academy of Sciences, Beijing, 100029, China
³University of Chinese Academy of Sciences, Beijing, 100049, China
⁴National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100101, China

We currently do not have a copyright agreement with this publisher and cannot display the abstract here