Estudio de marcadores ambientales sedimentarios y geoquímicos en los sedimentos del estuario de los ríos Tinto y Odiel

Résumé

The study of the geochemical features of the Tinto and Odiel estuarine sediments has allowed establishing a set of environmental proxies related to processes and sources of pollution, as well as the evolution of the environmental conditions during Holocene. Processes of saline mixing and acid neutralization that take place in the estuary have a strong influence on heavy metal and other trace elements behaviour, whose variation along the geological record is linked to the location of the estuarine mixing areas. The light REE show anomalous behaviour regarding to other systems not affected by acid drainage and their variation has allowed identifying three fractionation patterns depending on the pH conditions. The heavy metal pollution in the sediments has been evaluated by the combination of the enrichment factors and the exchange ability according to the degree of association with labile phases.