From excavation to analysis: Experimental insights on the impact of wet sieving processes on lithic use-wear traces

• Wet sieving leaves lithic use-wear traces intact, showing this post-excavation step poses minimal contamination risk. • Wet sieving causes only minor, microscopically distinct changes on flint tools, separable from functional traces. • Ruling out modern contamination at Pirro Nord 13 supports the integrity of prior functional analysis results. Lithic microscopic use-wear analysis plays a crucial role in reconstructing past human behaviour, offering insights into tool use, site function, and subsistence strategies. However, its reliability depends greatly on the identification of genuine use traces and is therefore continuously challenged by contamination, either in post-depositional conditions or in handling post-recovery. This study aims to investigate the impact of a common procedure in archaeological excavation – wet sieving – on the preservation of use-wear on flint tools, through experimentation and controlled field simulations conducted at the site of Pirro Nord 13. Results of the microscopic analysis indicate that wet sieving, despite concerning mechanics similar to specific abrasive weathering processes, does not significantly alter use-wear patterns. These findings reaffirm the resilience of functional traces and highlight the reliability of use-wear analysis in archaeological research when accompanied by rigorous protocols both in the field and in the laboratory.