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.