We present the results of comprehensive pre-site surveys and deep drillings in two clay pans in the central Atacama Desert of northern Chile, one of the driest deserts on Earth. The results of the site surveys as well as lithological and downhole-logging data of the deep-drilling operations highlight the potential of the sediment records from the PAG (Playa Adamito Grande) and Paranal clay pans to provide unprecedented information on the Neogene precipitation history of the hyperarid core of the Atacama Desert. 

In order to interpret the formation processes of subsurface salt wedges and polygonal patterned grounds from the northern Atacama Desert, we present a multi-methodological approach. Due to the high salt content of the wedges, we suggest that their formation is dominated by subsurface salt dynamics requiring moisture. We assume that the climatic conditions during the wedge growth were slightly wetter than today, offering the potential to use the wedges as palaeoclimate archives.

Chronological information on the evolution of the Namib Desert is scarce. We used U–Pb dating of silcretes formed by pressure solution during calcrete formation to track paleoclimate variability since the Late Miocene. Calcrete formation took place during the Pliocene with an abrupt cessation at 2.9 Ma. The end took place due to deep canyon incision which we dated using TCN exposure dating. With our data we correct and contribute to the Neogene history of the Namib Desert and its evolution.