Abstract DGP2026-66

Monturaqui Impact Crater: A showpiece for small crater formation processes and habitability changes

Alessandro Airo (1), Jenny Feige (1), Christopher Hamann (1), Lutz Hecht (1,2), Pouria Karami (1,2), Felix Kaufmann (1), Klemens Kirsch (1), Robert Luther (1), Benedikt Maurer (1), Tanja Michalik (1), Andrea Miedtank (1,2), Christof Sager (1), Cara Weihe (1,2), Kai Wünnemann (1,2).

(1) Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Germany, (2) Freie Universität Berlin, Planetologie und Fernerkundung, Germany.

Small impact craters are ubiquitous on all solid planetary surfaces in the solar system, yet most studies have focused on much larger, complex to basin-sized impact structures, resulting in a lack of knowledge on how small craters form and how their formation changes the surface and subsurface environmental conditions. Much of our current knowledge on crater formation is based on either simplistic laboratory-based small impact experiments, numerical models e.g., [1], or has been reconstructed from much larger and generally much older and therefore highly eroded terrestrial impact structures. Young and small impact craters bridge this gap such as the Monturaqui impact crater (MIC).

The MIC is in the Atacama Desert is the only known impact structure in Chile and is a rare example for simple craters that belong to this gap measuring 370 × 350 m in diameter and 34 m in depth [2]. Its relatively recent impact age of 663 ± 90 ka [3] in combination with the low precipitation, erosion, and sedimentation rates in the Atacama Desert yield a geomorphologically well-preserved and petrologically little-altered, simple impact structure [4]. This makes the MIC a unique study site and a natural laboratory for the investigation of processes and products associated with hypervelocity impacts of small iron projectiles on Earth and other planetary bodies.

Despite these advantages, the crater has only been scarcely investigated thus far [2-6]. Hence, we establish an interdisciplinary Chilean and German research network with the focus on studying the MIC. This initiative is supported by a DFG ‘Initiation of International Collaboration Programme’ grant (Number 572954263) supported a 10-day workshop in Chile including field work at the MIC in 2025. The goal of the network is to initiate pilot projects leading to long-term multidisciplinary studies in these research areas:

Impact physics of small crater formation processes
Petrography of MIC impactites and reconstruction of impactor–target interaction
Ablation and impact spherules through time and space
Impact-induced habitability changes and its implications

[1] Wünnemann, K., Zhu, M. H., & Stöffler, D. (2016). Impacts into quartz sand: Crater formation, shock metamorphism, and ejecta distribution in laboratory experiments and numerical models. Meteoritics & Planetary Science, 51(10), 1762-1794.

[2] Sanchez, J.; Cassidy, W. (1966). A previously undescribed meteorite crater in Chile. Journal of Geophysical Research (1896-1977). Vol. 71, no. 20, pp. 4891–4895. Available from doi: 10.1029/JZ071i020p04891.

[3] Valenzuela, M. et al. (2009). New Age Estimation of the Monturaqui Impact Crater. Public Access., p. 1.

[4] Ukstins, I. A. et al. (2022). An (U-Th)/He age for the small Monturaqui impact structure, Chile. Quaternary Geochronology. Vol. 67, p. 101217. issn 1871-1014. Available from doi: 10.1016/j.quageo.2021.101217.

[5] Cukierski, D. O. et al. (2025). Textural and compositional characteristics of metallic spherules in impact meltfrom Monturaqui crater, Chile. Meteoritics & Planetary Science. Vol. 60, no. 3, pp. 646–662. Doi: https://doi.org/10.1111/maps.14322.

[6] Rathbun, K. C. (2020). Monturaqui meteorite impact crater, Chile: a terrestrial analog for small craters on Mars. University of Iowa. Available from doi: 10.17077/etd.005565. PhD thesis. University of Iowa.