Geochemical characterization of sediment cores from the continental shelf off the western rias area (NW Iberian Peninsula)

• Type: Article in International Scientific Journal
• Date: 2005

Authors

corredeira, c (Author) Other; araujo, mf (Author) Other; gouveia, a (Author) Other; jouanneau, jm (Author) Other

Journal

Title: Ciencias Marinas

Vol. 31

Pages: 319-325

ISSN: 0185-3880

Publisher: Universidad Autonoma de Baja California

Indexing

ISI Web of Knowledge - 5 Citations

Scientific classification

FOS: Natural sciences > Earth and related Environmental sciences

Other information

Authenticus ID: P-000-3GC

Abstract (EN): The present work aims to understand the origin of sediments deposited in the Galician coastal zone and continental shelf. Selected sediment cores were studied using different geochemical approaches: grain-size measurements, carbonate determinations and elemental analyses. Chemical analyses were carried out by multielemental techniques: energy dispersive X-ray fluorescence spectrometry (EDXRF) and instrumental neutron activation analysis (INAA). The grain-size distribution demonstrated that samples collected off the rias (Vigo and Pontevedra) contain higher percentages of silt and clay. The carbonate enrichment measured in some sediment samples with different locations and granulometries seems to indicate that the sediments might have distinct origins: biological fluvial productivity in sediments off the rias and marine biogenic activities for the deeper continental shelf sediments. Chemical analyses made it possible to distinguish different elemental sources: lithogenic, anthropogenic and biogenic. The downcore profiles of the elemental composition showed signs of a recent continental contamination for Zn and to a lesser extent for As, although there are no signs of exportation to the adjacent continental shelf. Other elements that can indicate anthropogenic activities were present in low concentrations compared with reference values. The Zr distribution determined in sediments collected along a Straight line off Vigo Ria increases westwards, indicating an absence of recent exportation of this element from the continent.

Language: Spanish

Type (Professor's evaluation): Scientific

No. of pages: 7