The rotary diamond drilling in the Paranal claypan continued with an intense pace. We retrieved one core after another, giving us barely enough time to process them before getting a new one. After a huge effort and having surpassed several technical challenges, on Friday February 11^th we finally reached the basement of the basin at a depth of 171 meters. This finding confirms the geophysical estimates based on Transient Electromagnetics (TEM) performed in late 2019 by Barbara Blanco and other members of the CRC 1211, that were recently accepted for publication in the Journal of South American Earth Sciences. The contact to the basement rocks consists of a clear transition from coarse fluvial sediments to a highly weathered intrusive bedrock. By reaching the base of the sediment infill of the Paranal claypan while recovering most of the sampling material, we achieved the main scientific goal of this deep drilling operation!

After finalizing the hole 1B at 174 m, with the last two cores consisting entirely of bedrock, our drilling team moved to a new position. In order to facilitate the logistics for the drilling operation, we set the new hole 1C directly between the holes 1A and 1B. The purpose of this new hole is to duplicate the critical transition between fine-grained and coarse strata at approximately 52 meters depth and to recover the 50 meters of the fluvial sequence following directly underneath. The uppermost meters proved to be a new challenge for the rotary technique since we specifically asked not to use any additives or stabilizers as it is customary in this kind of drilling. It took almost two days to reach a depth of 45 meters and finally, on Monday February 14^th, we resumed the drilling activity with sample recovery. From there it took only two days to reach the target depth of 100 meters, which marked the official end of the drilling operation in the Paranal claypan. It was a great success and the numbers speak for themselves: altogether, we recovered 185 core segments with a total length of more than 260 meters and almost 100 % core recovery in average.

It took us a whole day to prepare our valuable freight for its long way to Germany. All the cores and bag samples were organized in a total of 19 pallets that were loaded in a big truck from the drilling company Superex and in our pickup trucks, finally finishing with the last rays of sun. On Thursday February 17^th we drove out of the claypan and brought all our precious samples to a shipping agency located in the north of Antofagasta, from where they will start their journey to Cologne. We are all looking forward to seeing them again soon back home!

After more than one year of intense preparations and extensive delays, we are finally taking off to the Roter Kamm. The 4-5 million year old impact crater and the Aurus clay pan close by are located in Southern Namibia inside the Sperrgebiet – one of the most remote places on earth.

We are a large team of 15 members from the Institute of Geology and Mineralogy, the institute of Geophysics and Meteorology in Cologne (A02/D07), our colleagues from the TUBAF in Freiberg plus our collaborators from the Geological Survey and the University of Namibia. For 22 days we will be living close to the Roter Kamm, cooking on fire and gas, sleeping in tents and working outside.

The extensive geophysical survey required us to ship roughly 1.6T and 6 cube-meter equipment from Cologne and the GFZ-Potsdam to Windhoek. We are using a bunch of different geophysical methods to optimally explore the Roter Kamm and the Aurus Clay Pan from shallow depth of ~5 m down to ~ 600 m. Two electromagnetic methods (TEM, AMT) and reflection/refraction Seismics shall provide sufficient depth and spatial resolution. All methods are capable of identifying sedimentary thickness and architecture, though each method has different strengths. Seismics is superior in resolving internal sedimentary structures, wheras TEM and AMT have a superior and large investigation depth. Besides, we are going to core the upper most few meters on both sites to investigate specific sediment composition and subrecnt sedimentation rates.

The geophysical and geological data shall reveal the potential of both sites for deep drilling operations in the 3^rd CRC phase to shed new light on long term Cenozoic climate development of the Namib desert.

After almost a week of rest in Antofagasta and reorganizing our logistics, we finally returned to the claypan last Sunday to continue our challenging drilling operation. As soon as we arrived back, the mystery of the footprints was revealed: a new member was added to our camp, a cute dog we named Dusty. Nobody knows where it came from, but now it stays with us in our small village to protect us during the night.

The limitations to reach further depths with the Sonic drilling and the switching to Diamond drilling brought lots of changes. A complete new set of trucks, tools and also a new crew of drillers were introduced to us. Larger modifications in the drilling equipment were necessary and the whole setup was completed on Tuesday morning.

The new drilling technique made it easily through the rocky transition zone at around 50 meters that was also visible in the seismic data. However instead of fine-grained material we found coarse sediments with large boulders, evidence of the early fluvial history of the basin. The Diamond drilling increased the speed of work drastically, allowing us to get deeper into the claypan with an average progress of 30-40 meters per day and with 100 % core recovery. After three full days of work we dug another 110 meters reaching 160 meters depth and are looking forward to find the boundary to the crystalline basement predicted by geophysics anytime soon.

In the meantime, the Sonic crew got their gear ready to move out of the claypan and into their new destination. But before leaving, our cook Ivan prepared a great “asado” as a goodbye for the old crew and a welcome of the new one. We took the chance to take a few group pictures with the sonic drillers and the scientists to remember our time together and the great job they did to recover this paleoclimatic treasure.