SERENA

The project aims to understand the spatial and temporal evolution of sedimentary facies in an active rift setting. The establishment of a well-constrained stratigraphic framework supported by radiometric datings will form the base for detailed sedimentological, palaeoecological and biogeochemical studies, and thus add to the thorough understanding of the flooding history, the timing of final closure of the connection to the Red Sea, and the development of microbial carbonates in open and closed systems. The further study of microbialites in these rapidly changing environments will give insights into their nature and significance and the processes related to microbial-mediated precipitation in diverse marine and continental settings.

The Danakil Depression, situated in the northern part of the Afar triangle (up to 120 m below sea level), is a tectonic depression associated to the rifting of the Afro-Arabian plateau, which is active since the Oligocene. Although, nowadays this depression only contains few small lakes, there is evidence that it has been flooded by the Red Sea during the Middle and Late Pleistocene. Multiple episodes of marine flooding and desiccation led to the deposition of diverse carbonate units surrounding the margins of the Danakil Depression and overlying directly the volcanic substrates. The deposits are ranging from open marine fringing coralgal reefs to hypersaline microbial reefs deposited in lacustrine environments. The basin center is characterized by the deposition of a more than 1000 m thick evaporitic succession. The excellent exposure and preservation conditions (due to an arid climate) of both marine to hypersaline syn-rift sediments at the margin of the Danakil depression and evaporitic sediments in the center of the basin form a unique window to study sediment deposition in a transitional rift basin paced by environmental fluctuations and their interplay with tectonic and magmatic events. Selected key-outcrops, situated at the western margin and the central part of the depression, are to be studied in detail in order to reconstruct the young flooding history of the Danakil depression.