Middle Devonian reef‑derived calciturbidites of western Ossa‑Morena Zone (Portugal): conodont biostratigraphy of the Eifelian Pedreira da Engenharia Limestone
The first biostratigraphical study on the complete Pedreira da Engenharia quarry section (Middle Devonian, SW Portugal) is presented. A total of 32 samples were collected from the three subsections (PE-A, quarry floor; PE-B and PE-C). This led to the identification of 15 species belonging to the gen...
| Autores: | , , , , , |
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| Tipo de documento: | artigo |
| Data de publicação: | 2024 |
| País: | España |
| Recursos: | Universidad Complutense de Madrid (UCM) |
| Repositório: | Docta Complutense |
| Idioma: | inglês |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/105882 |
| Acesso em linha: | https://hdl.handle.net/20.500.14352/105882 |
| Access Level: | Acceso aberto |
| Palavra-chave: | 56:551.734(469) Eifelian Conodonts Calciturbidites Pedreira da Engenharia limestone Cabrela Basin Ossa-Morena Zone Paleontología 2416.02 Paleontología de Los Invertebrados |
| Resumo: | The first biostratigraphical study on the complete Pedreira da Engenharia quarry section (Middle Devonian, SW Portugal) is presented. A total of 32 samples were collected from the three subsections (PE-A, quarry floor; PE-B and PE-C). This led to the identification of 15 species belonging to the genera Icriodus, Polygnathus and Tortodus. Four index species were identified: P. costatus; T. australis; T. kockelianus; and P. ensensis. The age for the Pedreira da Engenharia section was updated from the costatus zone (Boogaard, 1972) to the costatus-ensensis zones (lower to uppermost Eifelian). There is a thin part of the succession representing the kockelianus and, possibly, eiflius zones, together being represented by 1,5 m. A CAI value of 5-5.5 for the conodont elements indicates a maximum temperature of over 300 ºC. The Pedreira da Engenharia Limestone, together with the Odivelas Limestone, are evidence of the development of calciturbidite sedimentation associated with atoll-like structures (only preserved in Odivelas) along the SW boundary of Ossa-Morena Zone, being probably associated with the beginning of the subduction of the Rheic Ocean during Early to Middle Devonian times. |
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