Variaciones de espesor y de contenido en CaCO3 en los pares marga-caliza del Maastrichtiense inferior en Sopelana (Arco Vasco)
The Sopelana sea-cliff section exposes, in very good conditions, a continuous marl-limestone alternation from the Lower Maastrichtian in the deep Basque Arc domain. The 55 rhythms studied represent ~1100 ka and correspond to ~60cm/20ka. The marls are thicker than limestone layers and the Fischer dia...
| Autores: | , , , , , , |
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| Tipo de documento: | artigo |
| Data de publicação: | 2005 |
| País: | España |
| Recursos: | Universidad de Huelva (UHU) |
| Repositório: | Arias Montano. Repositorio Institucional de la Universidad de Huelva |
| Idioma: | espanhol |
| OAI Identifier: | oai:ariasmontano.uhu.es:10272/8684 |
| Acesso em linha: | http://hdl.handle.net/10272/8684 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Cyclostratigraphy Marl/limestone couplets Automatic calcimeter Early Maastrichtian |
| Resumo: | The Sopelana sea-cliff section exposes, in very good conditions, a continuous marl-limestone alternation from the Lower Maastrichtian in the deep Basque Arc domain. The 55 rhythms studied represent ~1100 ka and correspond to ~60cm/20ka. The marls are thicker than limestone layers and the Fischer diagram detects several shifts of high sedimentation and a well-marked minimum. The spectral analysis of the (%) CaCO3 content of the 30 selected rhythms (179 analysis, 18.74 m), confirms the rhythm with two frequency peaks, which correspond to the precession and eccentricity periods. The high-resolution analysis of four rhythms (<2cm/sample; 117 analysis, 2.04 m) shows a lack of symmetry and a different behaviour among them. The weathering surfaces point out an (%, CaCO3 ) enrichment tendency |
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