Exploring the potential of the North African speleothem archive
Swiss partners
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Universität Bern: Franziska Lechleitner (main applicant)
Partners in the MENA region
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Université Mohammed VI Polytechnique, Maroc: Yassine Ait Brahim (main applicant)
Presentation of the project
Our project had the goal to act as a pilot study and assess the potential of existing speleothem samples from Morocco as archives of climate and environmental conditions in North Africa during the mid- to late Pleistocene. Specifically, we were interested in whether the North African speleothem archive can resolve past periods of "green Sahara", their duration and regional extent, and the influence of different large-scale atmospheric circulation patterns on climate variability in Morocco during the late Pleistocene. This included examining its implications for early human (Aterian Iberomaurusian occuations) dispersals and evolution. Understanding these factors is crucial for better understanding the future impact of ongoing anthropogenic climate change in the region, as well as to provide a hydroclimatic context for the migration of early human populations in south Morocco.
For the project, we worked with a collection of existing carbonate precipitate samples from caves and tufa deposits in Morocco and focused on three aspects. 1) We conducted a review and synthesis of the available speleothem and other palaeoclimatological archives in Morocco and the wider North African region. Our approach involved a meticulous examination of the spatial and temporal distribution of these records, with the aim of assessing their coverage across different climatic periods and identifyig critical gaps in our understanding of the region's palaeoclimate. 2) We performed a high-resolution'sampling and geochemical analysis on one stalagmite covering a large portion of the last glacial period (14-76 thousand years before present (kyr BP)) that will give us insight into palaeoclimate and palaeoenvironmental conditions in this region during the Late Pleistocene. 3) We carried out a sedimentological investigation on tufa deposits spanning the past 600 kyr BP. Our approach involved sampling and analysing a series of laminated microbialites (microbial deposits) through stable isotope analysis. This allowed us to gain insights into past seasonality amplitudes of some key humid periods and their implications for human dispersals and evolution in the region over the last 600 kyr BP. Overall, the project has given us the tools and opportunity to critically assess the value of the collected speleothems (and tufa) and to begin more in-depth analytical work to provide more precisely dated and high resolution palaeoclimate datasets for the North African region.
