Stable isotope composition of Late Glacial land snail shells from Grotta del Romito (Southern Italy): Palaeoclimatic implications

Stable isotope composition of living and fossil land snail shells was determined at Grotta del Romito (Southern Italy) with the aim to reconstruct environmental and climatic variation in the area during Late Upper Palaeolithic. The investigated succession comprised 15 different excavated layers spanning between ca 13,000 and 14,500 yr cal BP. The oxygen isotope composition of snail shells indicates a marked decrease at the layer D8 suggesting a climatic deterioration consistent with the GI 1d climatic event (Older Dryas). This climate deterioration may have been related to a substantial decrease of mean annual temperature with associated changes in the regional atmospheric circulation. However, the environmental conditions at the time of shell's growth in the other intervals sampled suggest condition comparable to the present day. The carbon isotope composition of fossil snail shells is in agreement with other records, which indicate a general increase of the δ13C values of organic matter during Pleniglacial to Late Glacial caused by substantially lower atmospheric CO2 concentration at that time.