Paleoclimate instabilities during late Oligocene - Early Miocene in SW Europe from new geochemical climofunctions based on soils with pedogenic carbonate

In this study, two new climofunctions based on major elements are proposed from the study of 28 modern alluvial soils with pedogenic carbonate NE Spain. The first climofunction relates a base ratio (CaO, K2O) to mean annual temperature (MAT), and second one clayeness (Al2O3/SiO2) precipitation (MAP). both climofunctions, use parent material as normalizer gave best results, taking into account natural variability deposits. Application these 86 paleosols Oligo-Miocene successions in southern France central Spain was performed, combined morphological functions previously proposed, aim build detailed paleoclimatic data for key period climate history. This work provides high frequency record (range 10s 100 s kyr) paleoclimate fluctuations, estimated MAP methods very comparable (mean ~ 550 mm/yr). Estimated MAT MARP range precipitations) mainly exhibit same trends: 1) values followed by rapid decrease during early Aquitanian (from 18.8 13.5 °C; 80 20 mm), 2) warming trend towards middle (up 16.6 °C, 90 3) cooling (down 13.4 40 mm) late – Burdigalian. Comparisons paleontological remains indicate similar times lower paleosols. However, consistency between previous paleopedological investigations suggests regional pattern (southern Spain) precursor Mediterranean conditions that developed Neogene whereas humid prevailed western coastal basins Europe. Periods large amplitude fluctuations interpreted reflecting interrelation Miocene instability (Mi1, Mi1a events) continental climate.