Cleavers as Conservative Anchors across Technological Change in the Berach Basin (SE Rajasthan), India

Swati Verma

The Acheulean to Middle Palaeolithic transition marks a major technological reorganisation, yet its chronology and technological expression remain regionally variable and debated in South Asia. Where stratified and chronometrically dated sequences are scarce, micro-regional comparisons of lithic assemblages provide a robust way to track technological change. We apply this approach to the Berach Basin, where Palaeolithic occurrences have been reported since the 1950s, but were interpreted largely through typology and descriptive notes. Recent surveys documented 62 new Palaeolithic sites. These sites are grouped in three spatial clusters linked to distinct geological formations, revealing systematic contrasts in core reduction and blank production: the Eastern Cluster reflects a planned large-flake economy; the Western Cluster presents flake-based assemblages with prepared/discoidal approaches; and the Southern Cluster maintains large-flake production while broadening prepared-core strategies. Large cutting tools are dominated by cleavers (12.8%; n=125), which far outnumber handaxes (2.2%; n=22), with several localities yielding cleavers where handaxes are absent. Morphometric analysis of cleavers shows strong stability in cleaver shape across the basin. Kruskal–Wallis tests detect no inter-cluster differences in elongation or refinement, and PCA indicates a single continuous morphospace. This pairing of conservative cleaver end-product norms with restructured core systems supports gradual, locally mediated reorganisation across the Acheulean to Middle Palaeolithic transition.