INVESTIGADORES
ISLA Federico Ignacio
artículos
Título:
Aeolian sand dispersals and modern erosion processes...
Autor/es:
ISLA F; TOMAZELLI
Revista:
Thalassas
Editorial:
Universidade de Vigo
Referencias:
Año: 1999 vol. 15 p. 45 - 52
ISSN:
0212-5919
Resumen:
The Holocen sea-level fluctuation left coastal
lagoons and barrier environments along the shore-
lines of northem Argentina and southern Brazil.
Recent dunes are very young (usually less the
1000 years BP). These barriers are less than 4 km
width. They have grown from north to south in
Argentina, but it is not as clear wether a longshore
drift was dominant during the Holocene along the
Rio Grande do Sul coast.
In Argentina, Upper Pleistocene aeolian depo-
sits on the mainland denote the action of wester-
lies, but modern barrier dunes have an alongshore
component. In Mar Chiquita Barier (MCB, Buenos
Aires), these coastal dunes are transverse to the
winds coming from the SSW.
On the other hand, Patos Barrier (PB, Rio
Grande do Sul) was constructed by multiple
barriers of Pleistocene and Holocen age. Dominant
winds are today from the NE. The succession of
transverse dunes in that direction indicates a pro-
gressive sand scarcity landwards.
In MCB, dune succession is parabolic - trans-
verse - barchanoid - compound (startype) towards
the north. In PB, the succession is transverse - bar-
chanoid- barchans towards the south. In both
cases, sand availabitlity is higher towards the head-
lands of the barriers, north and shorewards.