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Table of Contents


Vol. 9 - 2010

Vol. 8 - 2009

Vol. 7 - 2008
SP 1 - 2008

Vol. 6 - 2007
Vol. 5 - 2006
Vol. 4 - 2005
Vol. 3 - 2004
Vol. 2 - 2003
Vol. 1 - 2001-2002

Notes for Authors
(PDF - 80 kb)



GeoActa Special Publication 1 2008


Acquisto online

GeoActa
an international Journal of Earth Sciences



Liliana Beatriz Teruggi
Dipartimento di Ingegneria Civile, Università degli Studi di Firenze, via Santa Marta 3, 50139, Firenze, Italy. e-mail: lteruggi@dicea.unifi.it.
Gustavo Adolfo Martinez, Julio Luis Del Rio
Centro de Geología de Costas y del Cuaternario, Universidad Nacional de Mar del Plata, Argentina

Geomorphology and textural composition of the coastal dunes south-east of Buenos Aires province, Argentina


Volume 3, 2004, pages 159-164

PDF (144 KB)
Abstract

The aim of this paper is to show some preliminary results of the research carried out on geomorphological and textural aspects of one of the areas of coastal dunes stretching almost continuously along the Atlantic coast in the province of Buenos Aires, in Argentina. The study area has a 12 km-development along the coast and is 2 km wide on average. The dune height locally is more than 30 meters.
Three stratigraphic units, separated by erosional surfaces, were defined. On the basis of geomorphological and textural variations, three zones have been recognized. In zone A there are two dominant accumulation features: parabolic dunes and paraboloid dunes. Several generations of blow outs marked by different degrees of vegetal covering can be observed. Zone B is characterised by well-developed transverse dunes with secondary crests on the windward slope. Zone C has the greatest sand availability and mobility, and shows the highest transverse dunes.
Wind velocity is the parameter that mainly controls dunes development. The most frequent winds are N-S directed, and are responsible for the reworking of the crests of the transverse dunes having a W -E orientation. These winds also give rise to the dominant erosion features, the blow outs.
Moving to the east, an increase in sand availability and in the average height of dunes, and a decrease in vegetation are observed.
The parabolic and paraboloid dunes owe their form to the vegetal cover present in the area. The erosion of parabolic dunes provides material that contributes to the formation of the paraboloid and transverse dunes located further east.

Keywords: Coastal dunes, Quaternary stratigraphy, Dunes evolution.