¹Carine Sadaka,¹Jérôme Gattacceca,²Matthieu Gounelle,²Mathieu Roskosz,^1,3,4Anthony Lagain,⁵Romain Tartese,⁶Lydie Bonal,¹Clara Maurel,⁷Rodrigo Martinez,^8,9Millarca Valenzuela
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.14307]
¹Aix-Marseille Université, CNRS, IRD, INRAE, CEREGE, Aix-en-Provence, France
²Muséum National d’Histoire Naturelle, Institut de minéralogie, de physique des matériaux et de cosmochimie—UMR7590, Paris, France
³Aix-Marseille Université, Institut ORIGINES, Marseille, France
⁴Space Science and Technology Centre, School of Earth and Planetary Sciences, Curtin University, Perth, Western Australia, Australia
⁵Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
⁶Institut de Planétologie et d’Astrophysique, Université Grenoble Alpes, Grenoble, France
⁷Museo del Meteorito, San Pedro de Atacama, Chile
⁸Universidad Católica del Norte, Antofagasta, Chile
⁹Center of Astrophysics and Associated Technologies CATA, Santiago, Chile
Published by arrangement with John Wiley & Sons

We present the outcome of search campaigns conducted in the Catalina Dense Collection area (DCA) located in the central depression of the Atacama Desert, Chile. The “Catalina Systematic Collection” (CSC) was assembled through systematic on-foot searches, resulting in a total of 1599 meteorites, before pairing, collected over a surface of 6.80 km2. This yielded a recovery density of 235 meteorites per km2 (67 meteorites >20 g per km2), making it the densest among hot deserts, even higher than the neighboring El Médano DCA collection. This confirms that the central depression of the Atacama Desert holds the highest meteorite density among hot deserts. We classified 457 meteorites weighing more than 20 g. After correcting for various recovery biases, we estimated a true meteorite density on the ground of 131 meteorites per km2 for meteorites >20 g before pairing. Using a probabilistic approach, we calculated an average pairing likelihood, yielding 71 meteorites >20 g per km2 after pairing. This high density is likely linked to an old age of the CSC, which would also explain the absence of carbonaceous chondrites, as they are more prone to alteration by abrasion. This long meteorite accumulation period is related to the long-term hyper-aridity and surface stability of the Atacama Desert, which have persisted for several million years. Meteorites from the CSC show less chemical weathering on average than in other hot deserts, despite the long accumulation period. The H/L ratio in the CSC is higher than in meteorites from other hot deserts, Antarctica, and falls, but similar to the El Médano collection, potentially reflecting variations in the composition of the meteorite flux over the past Myr.

^1,2G.K. Indu et al. (>10)
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14308]
¹Department of Geology, University of Kerala, Thiruvananthapuram, Kerala, India
²University College, Thiruvananthapuram, Kerala, India
Published by arrangement with John Wiley & Sons

Luna is a potential impact crater located in the Banni Plains of the Kutch Basin in western India. The suspected impactites, collected from a 1-m deep trench near the vicinity of the Luna structure, possess a range of physical (porosity and magnetism) properties. Petrographic studies reveal that these impactites are dominated by wüstite, kirschsteinite, spinel, olivine, and quartz (in decreasing order of abundance), with a few silica grains exhibiting potential planar fractures (PF). These impactites can be grouped into three distinct melt classes based on their wüstite and kirschsteinite content (classified as Ca-rich, Ca-poor, and transitional type). Spectroscopic analysis indicates a higher concentration of wüstite in magnetic samples, whereas weakly magnetic to non-magnetic samples have an elevated presence of kirschsteinite. Major oxide geochemistry comparison between the impactites and the surrounding Banni Plain sediments show that some Luna impactites have a chemical affinity with a terrestrial or transitional setting, whereas the remaining samples portray a non-terrestrial trend suggesting notable mixing of target rock and projectile material. Optically stimulated luminescence dating of the sediment layer containing the impactites yielded an age of 4045 ± 182 years for the impact, consistent with the earlier proposed age of <6900 years based on radiocarbon dating. The revised age places the Luna impact event much closer to the time frame of the Harappan Civilization’s decline, suggesting that it may have had a greater impact on the Harappan Civilization than previously thought.