Clay mineral and heavy metal distributions in the lower estuary of Huelva and adjacent Atlantic shelf, SW Spain
- 30 May 1997
- journal article
- Published by Elsevier BV in Science of The Total Environment
- Vol. 198 (2), 181-200
- https://doi.org/10.1016/s0048-9697(97)05450-8
Abstract
The Huelva estuary, on the south-western Spanish Atlantic coast, is an environment strongly polluted by acid mine drainage and industrial effluents. Clay mineralogy, heavy metal and particle-size distribution in estuarine and adjacent shelf sediments have been analyzed in order to identify the sources and transport pathways of the contaminated sediments. The estuarine sediments consist of detrital terrigenous minerals (illite, kaolinite, quartz, feldspars, dolomite and heavy minerals) derived from river catchments and coastal erosion, with biogenic components (calcite and aragonite) and minor authigenic minerals (pyrite and possibly gypsum). Mineral distribution pattern in the estuary-shelf system is controlled by grain-size sediment, physico-chemical conditions of waters and hydrodynamic factors. Important proportions of fine-grained sediments highly enriched in sulphide-associated heavy metals are supplied by the Tinto-Odiel river system. Most of these sediments are trapped when river waters reach the estuary because of flocculation processes during estuarine mixing, thus the estuary acts as a storage basin for metallic pollutants. In terms of public health, this estuary is well above recommended safety guidelines for most metals. Although the shelf sediments show metal concentration levels close to background values, eventually, a metallic plume emerges from the estuary to ocean, and consequently elevated metal concentrations can be locally detected on the inner shelf.Keywords
This publication has 11 references indexed in Scilit:
- Trace metals in the bivalve mollusc Chamelea gallina from the Atlantic coast of southern SpainMarine Pollution Bulletin, 1996
- Environmental impact of metals derived from mining activities: Processes, predictions, preventionJournal of Geochemical Exploration, 1995
- Crystallinity of Lower Cretaceous kaolinites of Teruel (Spain)Applied Clay Science, 1994
- Heavy Metal Anomalies in the Tinto and Odiel River and Estuary System, SpainEstuaries, 1993
- Clay mineral and heavy metal distributions in the northeastern North SeaMarine Geology, 1993
- Trace metals in sediments from the “Ria de Huelva”Toxicological & Environmental Chemistry, 1991
- Trace metal enrichments in waters of the Gulf of Cadiz, SpainGeochimica et Cosmochimica Acta, 1991
- The regulation of trace element concentrations in river and estuarine waters contaminated with acid mine drainage: The adsorption of Cu and Zn on amorphous Fe oxyhydroxidesGeochimica et Cosmochimica Acta, 1986
- Authigenic pyrite and gypsum in South West African continental slope sedimentsSedimentology, 1976
- Clay Distributions in Recent Estuarine SedimentsClays and Clay Minerals, 1975