Projects: A03, C04, C09, D02, D06

Between end of September and mid October 2022 a mixed group of scientists from the A03, C04, C09, D02 and D06 subprojects conducted a 21-day field excursion to the Atacama Desert guided by Dr. Benedikt Ritter and Dr. Damian Lopez. The group consisting of young researcher (two PhDs, five Post‑Docs) visited and conducted on-site experiments and sampling in all three focus areas of our CRC1211. With the collected samples and on-site data, we aimed to characterized the gradual change of aridity throughout the Atacama Desert. Major tasks focussed on extensive tephra sampling for our D06 Tephrochronology subproject, sampling of datable CaSO₄ samples and silicates for U/Pb dating of the D02 subproject, on-site analysis of dust emission using a mini ‘tornado’ machine (PI-SWERL) on various intact and destroyed soil and surfaces, as well as soil and sediment sampling for the characterization of biological fingerprints on and in CaSO₄ crusts and soil promoting surface stabilization. The campaign was rounded off with numerous samples for exposure dating and CaSO₄ wedges from old surfaces increasingly threatened by destruction (by nitrate/iodine mining) and a visit including sampling to the Salar Grande salt mine Bahia Blanca.

The intertwining interaction of all scientific branches of our group led to lively discussions in the field and close collaborations of all fields within an interdisciplinary approach.

Author: Benedikt Ritter

Fig.1: Due to the strong cooperation with our Chilean colleagues we are only able to conduct this CRC in the Atacama Desert. Again, many thanks to Prof. Eduardo Campos for all his help and patience with us. “Ver mas alla – See beyond” Photo: Benedikt Ritter

Fig.2: Our mini “tornado’ machine in action (PI-SWERL). Main question, at which windspeeds we can start the emission of dust and how does the soil and its composition and structure help to prevent aeolian erosion. Photo: Benedikt Ritter

Fig.3: Repeated measurements allow a statistical evaluation of windspeed and dust emissions. Experiments were conducted on various soil and surface types, as well as on intact and destroyed surfaces. Photo: Benedikt Ritter

Fig.4: Atacama soil and sediment sampling using empty trenches from presumably prospection work from nitrate/iodine mining companies. Photo: Benedikt Ritter

Fig.5: Halite outcrop at the Bahia Blanca Halite Mine in the northern part of the Salar Grande basin. Thanks to SPL for the visit and the scientific cooperation with us. Photo: Benedikt Ritter

Fig.6: Impact and creeping of the famous ‘camanchaca’ (fog) into the Salar Grande basin on its south-western rim. Photo: Benedikt Ritter