Workshop report: Afar Dallol drilling - ONset of sedimentary processes in an active rift basin (ADD-ON)

Rifts and rifted margins form when continents break apart and shape the continent-to-ocean transition on much of our planet. The sedimentary basins that result from continental rifting host unique sedimentary archives of palaeo-environmental and palaeo-climatic change required to understand complex natural processes. Rifts and rifted margins are key sites for natural resources (e.g. geothermal and hydrogen potential, critical metal resources, and CO 2 storage) and have an important societal relevance in the mitigation of geohazards such as earthquakes and volcanic activity. However, knowledge on the tectonic structure, sedimentary architecture, rapid palaeo-environmental change, fluid flow and hydrothermal circulation, deep subsurface biosphere, and their impacts on biogeochemical fluxes in rift basins remains poorly understood. Considering their large scientific potential and societal relevance, understanding the formation and architecture of rifts and rifted margins is now critical. The Afar rift is a world-class natural field lab where continental breakup can be directly observed. The northern part of Afar, the Danakil Depression, especially represents a unique snapshot in space and time when the continent ruptures and new seafloor and adjacent rifted margins form. However, deep subsurface records are missing in the basin. The ADD-ON project aims at deep drilling in the Danakil Depression to provide a unique sedimentary record in an active rift basin paced by global environmental fluctuations and their interplay with volcanic and tectonic events. To explore drilling targets and address scientific drilling objectives, an International Continental Scientific Drilling Program (ICDP) workshop was organized in Addis Ababa, Ethiopia, in August 2023. In total, 64 participants from 10 countries and all career stages respecting diversity and inclusion joined the workshop. They represented a wide range of scientific disciplines including government agencies, industry, local universities, and communities to discuss the ...