Interaction between sedimentary processes, historical pollution and microfauna in the Tinto Estuary (SW Spain)

摘要

The analysis of a short core collected in the Tinto Estuary (SW Spain) permits to delimitate the influence of historical mining activities on sediments and microfauna (Foraminifera and Ostracoda). In very shallow palaeochannels of the middle estuary, a first mining period (～3,600 cal years BP) caused high sediment pollution by Cu, with a significant diminution of the palaeontological record due to continuous acid mining drainage processes. In this core, the polluted levels derived from both Roman extractions (2,000-1,900 years BP) and the extensive mining activities between 1870 and 1935 have been eroded. The 1,800-200 years BP period is characterized by a limited mining activity and an important improvement of this ecosystem. In addition, the effects of recent industrial wastes have been limited in this area.