Zebra Stripe Formation

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

DFG project AG 432/1-1

PIs: Simon Matthias May & Lucas Ageby (Institute of Geography, Research Group for Geomorphology & Geochronology)

Duration: Dec 2024-Nov 2027

Understanding Zebra Stripe formation in the Atacama Desert, Chile

Our DFG-funded project investigates the origin and development of Zebra Stripes—distinctive geomorphic features found on hillslopes in the Atacama Desert, Chile. The research is conducted in collaboration with German, Chilean, and other international partners.

Zebra Stripes consist of alternating bands of coarse clasts and fine-grained, gypsum-rich sediments. These stripes are typically oriented obliquely to the contour lines of the hillslope. Notably, the coarse clast bands exhibit downslope sorting, with the largest clasts forming lobes at the lower ends of each stripe. While mechanisms such as overland flow and seismic shaking have been proposed, the precise processes driving their formation remain unresolved. Similarly, the timing of active stripe development is still poorly constrained.

Zebra stripe formation at a hillslope in the Atacama Desert
Monitoring meteorological station logging temperature, (lack of) precipitation, soil moisture, relative humidity etc. on a zebra striped hillslope
Chronology sampling rebra stripe casts for rock surface luminescence dating

Our objectives are to decipher the formation mechanism(s) using a combination of monitoring (remote sensing using UAV and fixed time-lapse cameras, meteorological, and seismic) and the tracking of past clast movements using rock surface luminescence profiles. We are also trying to improve the chronology of the stripes using rock surface luminescence dating and cosmogenic nuclide dating.

The significance of Zebra Stripes lies in their potential to reveal landscape evolution under hyper-arid conditions. In the Atacama, where water-driven processes are minimal, alternative mechanisms may dominate long-term geomorphic change. As such, Zebra Stripes serve as a valuable archive for understanding Earth surface processes in extreme environments—with possible analogues for extra-terrestrial landscapes.

Moreover, improved insight into their formation and preservation could offer clues about past and ongoing climatic shifts in the region.

We have done fieldwork in April and October 2025 and the next trip is preliminarily planned for March 2026.

By Lucas Ageby