quarta-feira, 18 de julho de 2012
A conduta dolosa da Ciência?
sábado, 7 de julho de 2012
Cadernos do GEEvH: Primeiro Volume
sexta-feira, 8 de junho de 2012
Territórios de Fronteira: Ciclo de 11 de Junho
domingo, 6 de maio de 2012
Territórios de Fronteira: Ciclo de Maio
quinta-feira, 5 de abril de 2012
Territórios de Fronteira: Ciclo de Abril
terça-feira, 20 de março de 2012
Guerra do Ultramar e repatriação dos restos mortais.
Vai ter lugar no dia 21 de Abril a conferência "Preservação de Memórias: exumação e identificação de soldados portugueses na Guiné Bissau. A oradora será a coordenadora da equipa que executou a operação: a Professora Doutora Eugénia Cunha. A sessão está marcada para a delegação sul do Instituto Nacional de Medicina Legal.
Apesar de à partida, esta conferência não aparentar ter uma temática arqueológica, este é um bom exemplo da aplicação das metodologias de campo da arqueologia a contextos forenses.
Não percam!
quarta-feira, 14 de março de 2012
Holocene interplay between a dune field and coastal lakes in the Quiaios– Tocha region, central littoral Portugal
Holocene interplay between a dune field and coastal lakes in the Quiaios– Tocha region, central littoral Portugal
- Randi Danielsen, IGESPAR, IP, Laboratory of Archaeosciences, Rua da Bica do Marquês 2, 1300-087 Lisbon, Portugal. Email: randidanielsen@gmail.com
Abstract
Coastal dune fields and dune-body associated lakes were studied through sedimentological, malacological and palynological analyses. Lake deposits and palaeosoil horizons gave new information about phases of aeolian activity and dune building, coastline and sea level, vegetation history and cultural impact. After a period of intense aeolian activity (Late Pleistocene) that limited soil-forming processes, a wet aeolian field, recorded by podzolized sands and interdune wetland deposits, was present in the region. Around 5000 to 4000 yr BP sea level reached the current level and the coastline was situated c. 1 km further inland compared with the present situation. Subsequently lagoon-barrier island systems developed c. 4000 yr BP. Vegetation in the region during this time was a pine/oak forest. Between 4000 and 1600 yr BP the forest was replaced by a semi-natural heathland. Later the heathland was degraded, allowing dune migration and finally formation of a desert-like landscape. This process was probably a consequence of a combination of deteriorating climate during the ‘Little Ice Age’ (LIA) and overgrazing. To counteract sand invasion, reforestation efforts were initiated in the region c. 300 years ago and locally along the coastal margin between 1924 and 1940. Formation of the row of freshwater lakes bordering the dune field at present was contemporaneous with the initial reforestation phase. A close relation between lake formation and accumulation of sand dunes was found. Various types of dunes were identified, truncated dunes, parabolic dunes and transverse/oblique dunes. Dune migration caused an eastward displacement of lakes.