Here we report the findings from excavations at the open-air Middle Palaeolithic site of Alapars-1 in central Armenia. Three stratified Palaeolithic artefact assemblages were found within a 6-m-thick alluvial-aeolian sequence, located on the flanks of an obsidian-bearing lava dome. Combined sedimentological and chronological analyses reveal three phases of sedimentation and soil development. During Marine Oxygen Isotope Stages 5–3, the manner of deposition changes from alluvial to aeolian, with a development of soil horizons. Techno-typological analysis and geochemical sourcing of the obsidian artefacts reveal differential discard patterns, source exploitation, and artefact densities within strata, suggesting variability in technological organization during the Middle Palaeolithic. Taken together, these results indicate changes in hominin occupation patterns from ephemeral to more persistent in relation to landscape dynamics during the last interglacial and glacial periods in central Armenia.