@article{d4283e0611d8440283b20e5e28d093ee,
title = "Water Abundance of Dunes in Gale Crater, Mars From Active Neutron Experiments and Implications for Amorphous Phases",
abstract = "We report the water abundance of Bagnold Dune sand in Gale crater, Mars by analyzing active neutron experiments using the Dynamic Albedo of Neutrons instrument. We report a bulk water-equivalent-hydrogen abundance of 0.68 ± 0.15 wt%, which is similar to measurements several kilometers away and from those taken of the dune surface. Thus, the dune is likely dehydrated throughout. Furthermore, we use geochemical constraints, including bulk water content, to develop compositional models of the amorphous fraction for which little information is known. We find the amorphous fraction contains ∼26- to 64-wt% basaltic glass and up to ∼24-wt% rhyolitic glass, suggesting at least one volcanic source for the dune material. We also find a range of hydrated phases may be present in appreciable abundances, either from the incorporation of eroded aqueously altered sediments or the direct alteration of the dune sand.",
keywords = "Curiosity rover, DAN, Mars, amorphous, neutron spectroscopy, water",
author = "Gabriel, {T. S.J.} and Craig Hardgrove and S. Czarnecki and Rampe, {E. B.} and W. Rapin and Achilles, {C. N.} and D. Sullivan and S. Nowicki and L. Thompson and M. Litvak and I. Mitrofanov and Downs, {R. T.}",
note = "Funding Information: We acknowledge the Dynamic Albedo of Neutrons instrument team and the broader Mars Science Laboratory team. This work was supported by the Mars Science Laboratory Participating Scientist Program, award number NNN12AA01C, and by the NASA Earth and Space Science Fellowship, award PLANET17F-0107. Computational support was provided in part by the Space Science and Applications group at Los Alamos National Laboratory and by the Research Computing center at Arizona State University. The authors thank Michael Line at Arizona State University for providing insight into statistical methods used herein and the authors thank Jack Lightholder at Jet Propulsion Laboratory for his early contributions to the project. All data from this work are publicly accessible on the Planetary Data System, www.pds.nasa.gov. Publisher Copyright: {\textcopyright}2018. The Authors.",
year = "2018",
month = dec,
day = "16",
doi = "10.1029/2018GL079045",
language = "English (US)",
volume = "45",
pages = "12,766--12,775",
journal = "Geophysical Research Letters",
issn = "0094-8276",
publisher = "American Geophysical Union",
number = "23",
}