Holocene morpho-sedimentary evolution of the wadi Inaouene catchment (Northern Morocco)
Exchange scientist
-
Mohammed Lghamour, PhD student
Supervisor at Swiss institution
-
ETHZ: Vincenzo Picotti
Supervisor at MENA institution
-
Sidi Mohamed Ben Abdellah University, Fez, Morocco: Lhoucine Karrat
Presentation of the projet
As it is already noted in the research plan, my scientific visit to the ETHZ, which began in 21/01/2020, was part of my doctoral research work carried out at the University of Sidi Mohammed Ben Abdellah of Fez supervised by Professor KARRAT Lhoucine. Our research aims to study the fluvial deposits and sedimentary activity of the Inaouène wadi (a river in northern Morocco) in order to reconstruct past environmental conditions in this area in correlation with North African and Mediterranean region. A further goal was to determine the factors (climate, tectonics ...) that forced its evolution during the Late Pleistocene and Holocene. Two years of preparation for this mobility might have led to very good results, because of the collaborative efforts of various financial and academic partners. Unfortunately, the health restrictions that everybody experienced after the spread of Covid-19 all over the world, have limited the work process, and of course had influenced the work plan established before. As a result of this unexpected situation, our initial plans have been adapted, and some proposed activity was not carried out. On the other hand, the main priority of the stay is successfully achieved: age dating of some alluvial deposits using charcoal particles sampled in the sediments, which contain radioactive Carbon 14. This activity, measured after a long process of preparation, in the Biogeosciences and Physics laboratory of the ETH, under the direction of the head of the Climate Change Studies Team; allowed us to achieve 36 ages for the Inaouéne deposits that vary between 33,000 and 100 years before the present (BP). These results will enable us to reconstruct the river evolution over time and define the timing of some events that took place in this valley and have influenced its behaviour.
Another important laboratory task was carried out, the measurement of the grains micro-size of detrital particles (sands, silts...) with smaller size, lower than 63 μm (microgranulometry) using the Laser microgranulometry tool in the sedimentology laboratory. The treatment of the result will improve the understanding about the deposit environment, in terms of water current energy that guides the deposit settling, and more in general on the river hydraulic behaviour.
I took part in almost all the analysis activities from the preparatory phase to the use of the devices, under the assistance of the technicians and professors of the ETH, who kindly taught me a lot about the above-mentioned techniques, completely new to me.
At the level of idea development and research maturation, several meetings and discussions with my supervisor, Dr. Vincenzo Picotti, were conducted within the Institute of Geology of the ETH. These exchanges allowed us, through precise observations of maps and cross sections I prepared for the study area, to change the old thoughts that postulate that Inaouene incises in a context of uplift instead of subsidence. The study of digital terrain models and satellite images has pointed out a well-defined fault corridor that may have affected the style and behavior of the valley, which very likely caused the change in the overall area of the catchement. Mr. Vincenzo Picotti taught me several techniques of evaluation and graphic analysis of the regional topography in order to determine the major factors that affect the river.
In consideration of a lithic tool found, and some fireplaces traces noticed in the field that indicate a well-developed ancient human activity on the two banks of the river, my supervisors and I agreed that it is very important to carry out an extended archaeological work, in order to seek other tools in the perspective of a future project, with the aim of understanding these unknown populations and there activit on the regional sedimentary and climatic dynamics. It should be noticed that the ages obtained by the 14C dating and that provided by paleoanthropological assessment of the collected tool overlap, which, on one hand testifies the accuracy of the radiocarbon dating, on the other hand suggest that the human material culture of the study area was in good connection with other North African settlements.
Presentation at the 2021 General Assembly of the European Geosciences Union