ITN opportunities: Summer-schools (Part 2)

 Inside Africa: Fossil source-to-sink systems, the diamond case and an eolian story, Namibia, 2023


In May 2023, from the 06th to the 20th, we travelled 3500 kms through Namibia to follow two different source-to-sink systems: the diamond system in the South and the aeolian system further north.

 

Figure 1 Bogenfels ghost town, Sperrgebiet - Farewell at the Pink House

The story of the diamonds is both old and young and starts with the diamonds being created within Jurassic Large Igneous Provinces - fields of volcanoes that were supplied with magma from the base of very thick and old continents and therefore can contain diamonds - all over Southern Africa. The craters were then eroded, sediments deposited in a sedimentary basin, which eventually was eroded too. The transport was interrupted by multiple tectonic tilts of the South African Plateau which impacted erosion and sediment transport, while extreme climate formed thick weathering profiles and crusts and thus enriched the sediment in diamonds across tens of millions of years. Today still, diamonds are transported by the Orange River to the Atlantic Ocean, and deposited along the Namibian coastline. We stayed a few days in the Sperrgebiet to visit multiple outcrops. The Sperrgebiet is a restricted area - you can imagine how excited we were to be allowed to enter, but also how logistically challenging this trip was!

There, we met representatives of the mining companies active in the area, namely Namdeb and Sperrgebiet Diamond Mining. They were with us for our whole stay in the Sperrgebiet, explained how they mine diamonds, interesting engineering practices and aspects of their work. We didn't visit the diamond mines at the coast, but heard many stories about how they are pushing back the ocean by building dams and then separating the diamonds from the remaining sediment through scanners and other machines. If you are interested, check out some satellite pictures (Diamond mines along the Namibian coast)!

Adventurous was our camp site in the Sperrgebiet! The building is the former school for children of the miners and is nowadays used for logistics. The loo was outside behind a small wall (Fig. 2 green arrow and bottom left picture). If it wasn’t foggy you could sit there and admire buildings of the ghost town further back or listen to the sounds of the Atlantic Ocean. With no lights around you can imagine the night sky! Although you couldn’t be afraid of wild dogs, who sometimes came close while we were resting. Don't worry! They were not interested in us humans but rather looking for water and food. One can only imagine how difficult it must be to find water in this arid place, as it sometimes doesn't rain for multiple years. Only the mist from the ocean brings some humidity at night! Check how little vegetation was growing there (Fig. 2)!

Figure 2: Campsite in the Sperrgebiet with a ghost town from diamond mining in the early 20th century.

 Afterwards, we went onto the second part of the training, north to the Namib Desert. The aeolian system also started a few millions years back, but is a lot younger than the first. We mostly concentrated on the formation of the Namib Desert, but also discussed questions like: How effective can different wind regimes transport sand? Can diamonds be wind transported? Or if you have an endless supply of sand, is the height of a dune limited? You can imagine how extensive discussions became when roughly 40 scientists of different expertise started to discuss! Check out these dunes and scroll out to watch how their shapes evolve coast-parallel and land-in-wards (dunes and how their shapes transition).

During our stay in Namibia, our local guides, who were also our drivers, chefs, and caretakers, from Matiti Safari were of great company and shared their knowledge about flora and fauna, but also about the culture and history of the country. It was a delight to learn so many societal aspects in-between our geology stops.

Throughout the field trip in Namibia, it was also visible how the group had grown together in roughly 2 years, which led to extensive scientific discussions on equal footing during the hour-long drives. Almost redundant to say how we PhD students had developed since Drangonstone, were more mature, skilled, independent, had more knowledge, and therefore were more confident. Thus stops at multiple outcrops did not want to end or had to be ended for the schedule’s/daylights sake and discussions were continued during and after dinner. One thing is certain, it is an excursion we will never forget.

 Summer-schools for the future

An interesting future for the summer schools is its future heritage: with the help of the network and participating experts, the ITN organisers succeeded in creating 3 major checkpoints throughout our projects. During all three years, we could see and follow our respective projects and show it during the summer schools. When looking from Dragonstone to Inside Africa!, it is impressive to see how everyone evolved, with discussions becoming more interesting each year. For our ITN, those summer-schools were a success.

However, it does not end here. In the future, Dragonstone and Inside Africa! will not only stay as a stepping stone for our careers, but it is planned, for future generations, to open those summer schools for other students. Our ITN members will try to make this possible in the future, to enable students from all over the world to experience top-science, combined with top-outcrops at an international level.

I hope that even if this post is a little different from the previous ones, that you enjoyed it. Stay tuned for more!

Comments

Post a Comment

Popular posts from this blog

What is a Source-to-Sink System?

Image
A  source-to-sink analysis is a method in sedimentary geology that integrates the studies of an entire sedimentary system from its upstream source in the continental area to the ultimate depositional sink , most commonly on deep basin s, in a process that can take from thousands to millions of years to be completed.   Source-to-sink system schematic (modified from Martinsen et al., 2010). There are three main elements in the source-to-sink system, source, transfer zone, and sink.       1) Source Source area in the source-to-sink system is in the continental realm where the main erosional processes occur. The erosion process in the source area is mainly driven by slow processes which can take millions of years: tectonics and climate. Tectonics generates high relief structures like mountains while climatic factors like precipitation bring water down the mountains. Hence, more sediment supply can be provided from the source area.  During the erosion processes, a rock will be broken down
Read more

What is a “Slow” Process in a Source-to-Sink System?

Image
The timescale of geological processes is very extensive. “Fast” processes like earthquakes, storms, or tides last from a couple of minutes to weeks. “Slow” processes, like orogenic uplifts or continent break-ups on the contrary can take up to millions of years (Fig. 1). In this post we will look into these slow processes in the context of the source-to-sink approach, introducing some concepts that provide a useful framework to understand the dynamics of these long processes in sedimentary systems. Figure 1. Temporal scale showing the differences in terms of duration of several geological processes as well as the common tools used to measure them. Bear in mind that the scale is logarithmic. Modified from Romans et al ., 2016. To understand slow geological processes in the context of source-to-sink analysis, we first have to understand the concept of steady-state topography. There are two major processes that drive topography inside a catchment (Fig. 2), one that creates positive rel
Read more

Methods to Investigate Source-to-Sink Systems

Image
ESRs in the field and in the lab. The sample processing starts by describing, counting, measuring, sampling, and investigating in the field. Samples are then taken to the laboratory for analytical work. Keep up with future posts to see the field and laboratory results! Much like building a complex puzzle, multiple components come together to foster an understanding of the evolution of S2S systems at various temporal and spatial scales. Some of these components are (1) understanding the major processes and fluvial dynamics acting on the system, (2) recognizing the changes or signals in the sedimentary record, (3) deciphering the environment necessary to produce a given signal within the record, and (4) contemplating other dynamics that would change the expression of an environmental event in the final rock/sediment record. Thus, studying S2S systems often requires an integration of research methods and the collaboration of specialists across different fields.     Pieces of the puzzle;
Read more