Estudio geoquímico de los sedimentos glaciolacustres de La Massana y Ordino (Andorra, Pirineos Orientales): influjo sedimentario entre lagos de obturación yuxtaglaciar interpretación paleoambiental

Geochemistry of glaciolacustrine deposits in the Pyrenean range is poorly studied. In that sense we have investigated the fine grained deposits of La Massana-Ordino paleolakes in order to increase the knowledge of such deposits. Chemical comparisons between basement rocks and glaciolacustrine deposits indicate an enrichment of chemical elements like Fe & Al. Because most of the catchment was occupied by glaciers, chemical basament denudation should be linked to glacial erosion in the Upper Pleistocene (UP). Since climatic weathering cannot be involved, geochemical variations are related to chemical precipitation in the paleolakes waters. In essence UP climate changes drive to changes in the chemical equilibrium that were recorded on glaciolacustrine sediments.