Composición isotópica de gasterópodos en secuencias aluviales holocenas de Bardenas Reales (Navarra): implicaciones paleoambientales

Abstract

Stable isotope composition of five species of gastropods from the Late Holocene alluvial record was studied in Bardenas Reales Natural Park (Navarre province) in order to deduce palaeoenvironmental information. Snails shells of five species from three morphosedimentary units (UM2: 4.245±55 to 3.005±55 BP, UM3: 2.745±55 to 925±65 BP and UM4: 210±45 to 85±45 BP) have been analyzed. Mean values of δ18O (V-PDB) and δ13C (V-PDB) are -2.19‰ and -6.0 for UM2, -1.17‰ and -6.7 for UM3 and -1.83‰ and -6.4 for UM4. Variability in isotopic signal among different gastropods species has also been observed. Changes in δ18O composition are controlled by isotopic composition of meteoric waters and, as a consequence, the warmer and drier environmental conditions during MU3 stage can be inferred