Local disappearance of bivalves in the Azores during the last glaciation |
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| Authors: | Sérgio P Ávila Patrícia Madeira C Marques da Silva Mário Cachão Bernard Landau Rui Quartau A M de Frias Martins |
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| Institution: | 1. Departamento de Biologia, Universidade dos A?ores, Ponta Delgada, Azores, Portugal;2. Centro do IMAR da Universidade dos A?ores, Horta, Azores, Portugal;3. MPB – Marine Palaeobiogeography Working Group of the University of the Azores, Rua da M?e de Deus, Ponta Delgada, Azores, Portugal;4. Departamento e Centro de Geologia, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal;5. Departamento de Geologia Marinha, INETI, Estrada da Portela, Zambujal, Alfragide, Portugal;6. CIBIO Centro de Investiga??o em Recursos Genéticos – Pólo A?ores, Departamento de Biologia, Universidade dos A?ores, Ponta Delgada, Azores, Portugal |
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| Abstract: | The Pleistocene (Eemian) outcrops of Lagoinhas and Prainha, located at Santa Maria Island (Azores), were investigated and their fossil mollusc content reported. These studies revealed that the last glaciation affected two groups of molluscs: the ‘warm‐guest’ gastropods with West African or Caribbean affinities (e.g. Conus spp., Cantharus variegatus, Bulla amygdala, Trachypollia nodulosa) and shallow bivalve species mainly associated with sandy habitats (Ensis minor, Lucinella divaricata, and probably Laevicardium crassum). In this paper we focus on this group of bivalves, which has since locally disappeared from the Azores. We relate the local disappearance of these bivalves in the Azores with the lack of sand in the shelf. The specific characteristics of the Santa Maria shelf combined with the sea‐level drop during the Weichselian prevented deposition of the lowstand deposits and permitted erosion of the previous ones, leaving the shelf without a sediment cover. Copyright © 2008 John Wiley & Sons, Ltd. |
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| Keywords: | Azores Pleistocene (Eemian) bivalves sea level local disappearance |
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