Karst record of Holocene climate and human-induced changes in surface processes in the northern Apennines of Italy

Underground karst is a sensitive component of the Earth's Critical Zone (ECZ), capable of preserving changes in its dynamics driven by both natural and anthropogenic forces. In this study, we examine the Holocene sedimentary archive preserved in Tana della Mussina Cave (TdMC) in the northern Apennines of Italy. This archive includes clastic and chemical (speleothem) sediments, as well as archaeological deposits linked to human occupation of the site since the Copper Age. Our reconstruction indicates that sedimentation in the cave responded to changes in the hydrology of the karst system, alternating between phases of clastic deposition and periods of sedimentary hiatus, along with a documented phase of speleothem precipitation. Clastic sedimentation occurred particularly after the Greenlandian/Northgrippian boundary and again at the onset of the Meghalayan phase of the Holocene, likely in response to increased water availability, which led to the accumulation of fluvial sediments transported through the TdMC catchment. In contrast, speleothem deposition took place later, between 3800 and 2200 years BP. From around 5500 years BP, clastic sedimentation is marked by a significant accumulation of charcoal and lumps of heated sediment/soil. We interpret this evidence because of human activity, specifically extensive deforestation, which has been archaeologically documented in the region since the Copper Age. The slash-and-burn technique, used to clear land for pasture or agriculture, increased soil erosion rates, leading to a greater influx of sediments into the karst system, including charcoal and remnants of heated soils. This case study provides an example of early human land use change impacting surface processes and influencing the dynamics of the ECZ. • We investigate the clastic and anthropogenic deposits and speleothems in the Tana della Mussina Cave. • Clastic sediments developed following increased soil erosion in the karst catchment. • Soil erosion was intermittently triggered by human impact since the Early Holocene. • The slash and burn practice caused surface instability and increased sediment flux into the karst system. • This study confirms an early human impact on Earth's Critical Zone processes.