Climate Variability in a 3.8 Ma Old Sedimentary Record from the Hyperarid Atacama Desert

• DOI: 10.2139/ssrn.4634861
• Publication Date: 2023-11-16T12:17:58Z
• Authors: Felix Leo Arens; Jenny Feige; Alessandro Airo; Christof Sager; Lutz Hecht; Lucas Horstmann; Felix E. D. Kauf...; Johannes Lachner; Thomas Neumann; Norbert Nowaczyk; Ferry Schiperski; Peter Steier; Alexandra Stoll; Ulrich Struck; Bernardita Valenz...; Friedhelm von Bla...; Hella Wittmann; Lukas Wacker; Dirk Wagner; Pedro Zamorano; Dirk Schulze-Makuch
• Keywords: Desert (philosophy); Paleoclimatology; Desert climate

The hyperarid Atacama Desert is one of the driest and oldest deserts on Earth, rendering it a valuable climate archive. However, unraveling its past particularly challenging few studied paleoclimate records region reveal strong temporal spatial variabilities. To enhance our understanding these dynamics we investigated sedimentary record in Yungay valley located southern Desert. We employed paleomagnetic radiocarbon dating, for first time sediments, meteoric 10Be/9Be based method determining depositional age. respective 4.20 m deep profile comprises lower alluvial fan deposit with maximum age (3.8±0.8) Ma, an upper 1.84 thick clay pan that has accumulated over last 19 ka. Multiple proxies including grain size, salt concentration, elemental composition indicate aridity increase around 2.3 Ma ago repeated dry wet phases during late Pleistocene Holocene. latter climatic shifts can be assigned to variabilities South American Summer Monsoon El Niño Southern Oscillation moisture sources from Atlantic Pacific Ocean, respectively. This study provides deeper insights into heterogeneous underlines importance interdisciplinary investigations decipher systems their effect potential habitable regions such extreme environment.