|
|||||
|
|
Sea-level changes during the Pleistocene-Holocene in the NW coastal zone of Portugal |
|
| Authors: | Helena Maria Granja G Soares de Carvalho |
| Institution: | Universidade do Minho, Departamento de Ciěncias da Terra, Campus de Gualtar, 4700 Braga, Portugal;;Rua Elisio de Moura, 62, R/C 4700 Braga, Portugal |
| Abstract: | Research was undertaken to establish the present coastal dynamics of the area south of Espinho, Portugal, with special emphasis on the migration inland of beaches and the retreat of cliffs during at least the last century. Besides the Holocene units (the Silvalde-Paramos tijuca Formation, 2310 ± 80 yr BP to 500 ± 80 yr BP, and the Cortegaca Beach Formation, 6850 ± 60 yr BP to 950 ± 80 yr BP), a Pleistocene unit (the Maceda Beach Formation, 29, 600 ± 690 yr BP to 14300 ± 160 yr BP) with trunks of Pinus sylvestris was recognized. The Cortegaca Beach Formation comprises a truncated podzol profile, the Al horizon dating from 3490 ± 60 yr BP to 950 ± 80 yr BP. The study and the dating of the Pleistocene and the Holocene formations suggest a model of evolution related to sea-level fluctuations and neotectonics, during the interval between 29,000 ± 690 yr BP and the post-XVth century (Little Ice Age). The final purpose of the research is to apply the results to the prediction of the coastal zone evolution, and particularly to influence policy with respect to coastal zone management. This policy must take into account the inland migration of the beaches and the cliff retreat as a consequence of the natural dynamics of the earth that cannot be arrested or controlled by man. |
| Keywords: | |