Key driving mechanisms and chronology of geomorphic processes in hyperarid landscapes – Combining field-based geomorphological investigations and rock surface luminescence dating techniques

• Applicants: Dr. Lucas Ageby; Dr. Simon Matthias May
• Subject Area: Physical Geography
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 541815024

This proposal offers a unique possibility to better understand geomorphic processes under extreme hyperaridity, which are poorly understood and for which process rates are essentially unknown. It specifically aims at studying processes, drivers and time scales of hillslope sediment production and transport in hyperarid landscapes by investigating the so-called zebra stripes, arguably the most enigmatic and widespread hillslope landform in the central Atacama Desert. Knowledge on hillslope sediment dynamics is key to (i) successfully modelling long-term hyperarid landscape evolution, (ii) refining and quantifying local- to global scale elemental and material cycles, and (iii) assessing the impacts that climate change had – and continues to have – on our environment in drylands and adjacent regions. Beyond Earth, results from this project have direct relevance to the development of extra-terrestrial geomorphology, as the Atacama Desert is considered the closest terrestrial analogue to Mars. The proposed project will combine geomorphological investigations and the application of different monitoring approaches (Work Package 1 (WP1)) on the one hand, and rock surface luminescence dating techniques supplemented by terrestrial cosmogenic nuclide exposure dating (WP2) on the other hand. WP1 will carry out repeated field investigations at selected key sites in the hyperarid core of the Atacama in order to decipher landform characteristics and to conduct on-site monitoring of local environmental conditions and processes, which will be followed by detailed analyses of sediment samples and monitoring results in the lab. WP2 will gather both relative and absolute chronological information on zebra stripe formation time scales, which will be obtained by utilising the innovative rock surface luminescence dating technique, combined with terrestrial cosmogenic nuclide measurements. By employing the complementary expertise of 15 researchers and different research directions, as represented by WPs 1 and 2, we expect in-depth insights into the nature and origin of zebra stripes and their significance for understanding Earth surface processes under extreme hyperaridity. While the geomorphological work (WP1) will provide the essential background for the chronological investigations of WP2, the luminescence-based rock surface dating technique (WP2) will add information on process activity or inactivity, thereby in turn clarifying geomorphological problems addressed in, and complementing the investigations of WP1. Ultimately, this proposal builds on concerted national and international collaborative efforts facilitating the interchange of students and/or postdoctoral research fellows.

• DFG Programme: Research Grants