Dunes and Holocene deposits of the coastal zone north of Mondego Cape, Portugal
Granja, H.M.; de Carvalho, G.S. (1992). Dunes and Holocene deposits of the coastal zone north of Mondego Cape, Portugal, in: Carter, R.W.G. et al. Coastal dunes: geomorphology, ecology and management for conservation: Proceedings of the 3rd European Dune Congress Galway, Ireland, 17-21 June 1992. pp. 43-50
In: Carter, R.W.G.; Curtis, T.G.F.; Sheehy-Skeffington, M.J. (Ed.) (1992). Coastal dunes: Geomorphology, ecology and management for conservation: Proceedings of the 3rd European Dune Congress Galway, Ireland, 17-21 June 1992. A.A. Balkema [etc.]: Rotterdam. ISBN 90-5410-058-3. 533 pp., meer
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| Auteurs | | Top |
- Granja, H.M.
- de Carvalho, G.S.
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| Abstract |
Several systems of dunes with ridges of different orientation have been recognized south of Aveiro lagoon, northern Portugal, while further north they are not so easily observed. Associated with these dunes are both recent and older podzols. Some of the dunes are of a post-Mediaeval age as they cover cemeteries dating from the Eleventh to Fourteenth centuries. In this region, wind worn pebbles, perhaps related with the end of the Würmian glaciation, are present but it is not possible to link them to any system of dunes that would have pre-dated this period. The Ao podzolic horizon from Cortegaca Beach provided carbon fragments 14C dated to 165O±160BP. The sands that underlie these podzols are probably wave-lain rather than aeolian. To the north of the Aveiro lagoon, the dunes are associated with lagoonal silt deposits, rich in shells and diatoms and overlain by soils with plant remains and tree trunks. The shells of the silty deposits have an age comprised betw 2200±80 and 2310±90 BP (in the north ,in Esposende, the oldest dating available till now is of 325O±100 yr BP) and the overlying soils have an age between 101O±80 and 2540±90 yr BP. The spread of 14C dating, from 325O±l00 till 1010±80 BP, may span the period of formation of the barrier lagoon system. The related systems of dunes, paleosoils and lagoonal deposits provide information on the evolutionary history of the present barrier lagoon system of Aveiro. This system has an extensive economic and social role and is subjected to a strong anthropogenic impact threatening its future. |
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