Title
Recent sedimentation and mass accumulation rates based on <sup>210</sup>Pb along the Peru-Chile continental margin
Date Issued
01 October 2004
Access level
metadata only access
Resource Type
journal article
Author(s)
Muñoz P.
Lange C.B.
Hebbeln D.
Salamanca M.A.
Dezileau L.
Reyss J.L.
Benninger L.K.
Abstract
The concentrations of the natural radionuclide 210Pb were measured in sediment samples collected with a multicorer, boxcorer, and gravity corers along the Chilean continental margin (20-45°S) in order to estimate sedimentation rate (SR) and mass accumulation rate. This database was compared with previously obtained results from central Peru (Callao). 210Pb activities decreased exponentially with core depth and profiles showed a deepening of the 210Pb in excess (unsupported) in the sediments from north to south (∼6-18 cm sediment depth off Peru and northern Chile vs. 8-35 cm off central and southern Chile. An onshore-offshore decrease of surface activities was observed off central Peru whereas the reverse was true for surface activities along the Chilean margin. SRs increased from north (0.04-0.17 cm yr -1) to south (0.09-0.29 cm yr -1). Across the shelf, higher rates were observed at deeper sites, especially at those close to submarine canyons, except off central Peru, where SRs showed similar values through the slope area. Off northern Chile and central Peru, SRs seem to reflect the export of particles over the shelf and redistribution processes such as slumps and lateral transport. In contrast, SRs in central and southern Chile seem to be controlled by several additional factors that modulate the settling particles, such as onshore precipitation and river runoff. In addition, the more complex topography of the southern Chile margin allows for settling or winnowing areas. © 2004 Elsevier Ltd. All rights reserved.
Start page
2523
End page
2541
Volume
51
Issue
20-21
Language
English
OCDE Knowledge area
Otros temas de medicina clínica
Scopus EID
2-s2.0-9644290943
Source
Deep-Sea Research Part II: Topical Studies in Oceanography
ISSN of the container
09670645
Sources of information:
Directorio de Producción Científica
Scopus