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A major challenge in subaqueous palaeoseismology is to understand the relationship between an earthquake/tsunami and a sedimentary event deposit recorded in drillcores. Expedition 381 of the International Ocean Discovery Program was dedicated to understanding the development of the Corinth Rift, Greece. Its drilled cores provide a potentially important resource to better understand depositional mechanisms of sedimentary event deposits within changing open marine to (semi‐)isolated environments. To achieve this, U‐channels and spatula samples were analysed from the topmost part (0–65 m below seafloor maximum depth) of holes M0078B and M0079A (ca 0–25 ka), using high‐resolution X‐ray microtomography in combination with grain‐size, magnetic and X‐ray fluorescence measurements. Structures and grain fabric are resolved down to 10 μm in voxel size, characterizing the geometry of the basal surface of 'turbidite+homogenite' sedimentary event deposits, and the internal base‐upward evolution at high‐resolution scale. This analysis suggests that these types of deposits are more complex than previously proposed, especially at the transition between the basal coarse turbidite sub‐unit and the fine‐grained homogenite upper sub‐unit, as well as within the homogenite. Combined with the other observations and parameters, X‐ray microtomography results are consistent with the interpretation of the Corinth 'turbidite+homogenite' deposits as having predominantly originated from seismic and/or aseismic slope failures followed by tsunami/seiche effects, despite subtle differences according to depositional environment. [ABSTRACT FROM AUTHOR]