5 documents found, page 1 of 1
Palaeobiogeography of NE Atlantic archipelagos during the last Interglacial (MI...
Melo, Carlos S.; Marques da Silva, Carlos; Scarponi, Daniele; Martín-González, Esther; Rólán, Emilio; Rojas, Alejandra; Martinez, Sergio; Silva, LuísIn order to understand the complex evolutionary processes and patterns that explain current island biodiversity, large datasets and long-term analysis are required. The Last Interglacial (LIG) was one of the warmest interglacials during the last million years. How species mobility changed during this period in the Macaronesia geographical region has long intrigued scientists. It is well established that the nor...
Pleistocene coralline algal buildups on a mid-ocean rocky shore : Insights into...
Rebelo, Ana C.; Rasser, Michael; Ramalho, Ricardo S.; Johnson, Markes E.; Melo, Carlos S.; Uchman, Alfred; Quartau, Rui; Berning, Björn; Neto, Ana I.Located on the northern coast of Santa Maria Island (Azores Archipelago, central North Atlantic), the Lagoinhas section preserves a carbonate buildup correlated with Marine Isotope Substage (MIS) 5e, the warmest interval of the Last Interglacial. The buildup is formed mainly by crustose coralline algae (CCA) identified as Spongites sp., and some subordinate crusts of Lithophyllum sp. and Neogoniolithon sp., as ...
A geological record of multiple Pleistocene tsunami inundations in an oceanic i...
Madeira, José; Ramalho, Ricardo S.; Hoffmann, Dirk L.; Mata, João; Moreira, MárioIn the Central Atlantic archipelagos - the Canaries, Cape Verde, Madeira and the Azores - tsunami hazard is often regarded as low, when compared with other extreme wave events such as hurricanes and storms. The geological record of many of these islands, however, suggests that tsunami hazard may be underestimated, notwithstanding being lower than in areas adjacent to subduction zones, such as the margins of the...
Fajã dos Milagres : o desvendar da formação de fajãs detríticas com sistemas la...
Melo, Carlos S.; Ramalho, Ricardo S.; Borges, Paulo A. V.Fajãs detríticas costeiras com sistemas lagunares constituem locais de elevada riqueza geológica, biológica e paisagística. E do conhecimento geral que a formação de fajãs detríticas costeiras esta intrinsecamente ligada a evolução de vertentes litorais alcantiladas, típicas em ilhas vulcânicas, e aos processos de desmonte associados a esta evolução (e.g. ‘quebradas’). Não obstante este conhecimento, pouco se c...
The emergence of volcanic oceanic islands on a slow-moving plate: the example o...
Ramalho, Ricardo S.; Silveira, António Brum da; Fonseca, Paulo E.; Madeira, José; Cosca, Michael; Cachão, Mário; Fonseca, Maria M.; Prada, Susana N.<jats:title>Abstract</jats:title><jats:p>The transition from seamount to oceanic island typically involves surtseyan volcanism. However, the geological record at many islands in the NE Atlantic—all located within the slow‐moving Nubian plate—does not exhibit evidence for an emergent surtseyan phase but rather an erosive unconformity between the submarine basement and the overlying subaerial shield sequences. Th...