Melting experiments of a L6 ordinary chondrite: implications for the formation of alkali-rich achondrites

Research data of the paper: "Melting experiments of a L6 ordinary chondrite: implications for the formation of alkali-rich achondrites"Iannini Lelarge S.1, Masotta M. 1,2, Folco L. 1,2, Ubide T.3, Suttle M.4, Pittarello L.5,61 Dipartimento di Scienze della Terra, Università di Pisa, Via Santa Maria 53, 56126, Pisa, Italy2 CISUP, Centro per l’Integrazione della Strumentazione Università di Pisa, Lungarno Pacinotti 43 Pisa, 56126, Italy3 School of Earth and Environmental Sciences, The University of Queensland, Brisbane, 4102 QLD, Australia4 School of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK 5 Naturhistorisches Museum, Mineralogisch-Petrographische Abteilung, Burgring 7, 1010 Vienna, Austria6 Department of Lithospheric Research, University of Vienna, Josef-Holaubek-Platz 2,1090 Vienna, AustriaTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Asteroids accretion, differentiation, and break-up in the Vesta source region: evidence from cosmochemistry of mesosiderites

The cosmochemistry of meteorites provides unique clues on asteroids accretion, differentiation, collisional break-up and reassembly - processes of critical importance for understanding planet formation in the early solar system. Mesosiderites are a complex group of achondrites whose nearly 50:50 metal-silicate composition is interpreted in the literature as resulting from the mixing of core and crustal materials derived from differentiated asteroids. Because of their complex nature and contrasting geochemical, isotopic, and spectroscopic data, the formation mechanism of mesosiderites is still poorly understood and is open to a large variety of planetary differentiation scenarios and collisional histories. In this study, based on new petrographic and geochemical data of 16 mesosiderites, we investigate in detail the proposal that mesosiderites are related to the howardite-eucrite-diogenite (HED) meteorite group, whose parent body is widely considered to be asteroid 4 Vesta (∼500 km diameter), the target of the recent NASA’s Dawn mission. We present the first high precision oxygen isotope analyses on the matrix of a set of mesosiderite samples, coupled with new chemical and petrographic analyses of mesosiderites Um Hadid, Estherville, and Mount Padbury. Concordant Δ17O values between mesosiderites (–0.241 ± 0.015 (2σ)) and howardite-eucrite-diogenites (−0.241 ± 0.017‰ (2σ)) indicate that they derived from the same oxygen isotope reservoir, but petrological evidence, in particular the distinctly lower Fe/Mn ratios and the larger lithological diversity in mesosiderites, indicates that they formed within different parent bodies. This suggests that mesosiderites and howardite-eucrite-diogenites originated in distinct parent bodies that accreted in the 4 Vesta source region but experienced different geologic evolution in terms of crustal differentiation and impact history, which were more complex and catastrophic in the mesosiderite parent body

Laboratory measurements of anhydrous minerals mixed with hyperfine hydrated minerals to support interpretation of infrared reflectance observations of planetary surfaces

Identification of water in our Solar System is a key point to understanding the formation and evolution of planetary bodies as well as for astrobiological studies. Scientists identified hydrated minerals as a prime source of H2O in our Solar System. Minerals such as clays, serpentines and other phyllosilicates were discovered by orbiter and lander spacecraft and ground observations on a large variety of rocky surfaces from Mars to small asteroids using InfraRed (IR) spectroscopy as primary technique. It has already been observed that in the presence of large amounts of hydrated minerals in mixtures with anhydrous minerals, the IR spectra can be dominated by the features of hydrated minerals. However, it is still poorly studied how the IR spectra change in presence of different grain size of the two components.The goal of this study was to investigate the infrared spectroscopic features of anhydrous mineral spectra in presence of low amounts of small grain size hydrated hyperfine particles. We prepared several mixtures using 1 wt% and 5 wt% of very small grain size (< 10 mu m) hydrated minerals and 95 wt% and 99 wt% of larger grain size (200-500 mu m) anhydrous minerals. We measured the IR reflectance spectrum of these mixtures in the range 8000-400 cm-1 (1.25-25 mu m). Results presented here show how the presence of a very limited amount of hy-drated minerals with grain size one order of magnitude smaller than the anhydrous component is sufficient to change the IR spectrum, especially in the Near-InfraRed (NIR) region where some of the major hydrated features manifest. On the contrary, the Mid-InfraRed (MIR) part of the spectrum (also identified as thermal infrared) is definitely less affected and anhydrous mineral features continue to be dominant with slight modifications. This result is of pivotal importance for correctly interpreting the IR reflectance observations of planetary bodies such as Mars or asteroids where a mixing of anhydrous and hydrated minerals can be observed. The presence of strong spectroscopic features due to hydrated minerals can be misinterpreted as a large abundance of this material instead of a spectroscopic effect

Deciphering Remote Sensing Data from Micro- to Macro-Scale: New Laboratory Investigations on Grain Size and Mineral Mixing in Support of Solar System Exploration

International audienceWe present laboratory results on the mixing of different grain size and dark materials and their effect on the behavior of infrared spectra in the near- to mid-infrared range in support of remote sensing data interpretation from rocky surfaces

Deciphering Remote Sensing Data from Micro- to Macro-Scale: New Laboratory Investigations on Grain Size and Mineral Mixing in Support of Solar System Exploration

International audienceWe present laboratory results on the mixing of different grain size and dark materials and their effect on the behavior of infrared spectra in the near- to mid-infrared range in support of remote sensing data interpretation from rocky surfaces

Deciphering Remote Sensing Data from Micro- to Macro-Scale: New Laboratory Investigations on Grain Size and Mineral Mixing in Support of Solar System Exploration

International audienceWe present laboratory results on the mixing of different grain size and dark materials and their effect on the behavior of infrared spectra in the near- to mid-infrared range in support of remote sensing data interpretation from rocky surfaces