Emersión de una plataforma carbonatada aislada. Un ejemplo en el Prebético de Jaén (Hauteriviense-Barremiense, Zonas Externas Béticas)

  1. J.M. Molina 1
  2. C. Jiménez de Cisneros 2
  3. L.M. Nieto 1
  4. P.A. Ruiz Ortiz 1
  5. J.M. Castro 1
  6. G.A. de Gea 1
  7. M. Company 3
  1. 1 Universidad de Jaén
    info

    Universidad de Jaén

    Jaén, España

    ROR https://ror.org/0122p5f64

  2. 2 Instituto Andaluz de Ciencias de la Tierra. CSIC-Universidad de Granada
  3. 3 Universidad de Granada
    info

    Universidad de Granada

    Granada, España

    ROR https://ror.org/04njjy449

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Revista:
Geotemas (Madrid)

ISSN: 1576-5172

Ano de publicación: 2021

Título do exemplar: X Congreso Geológico de España

Número: 18

Páxinas: 170

Tipo: Artigo

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Outras publicacións en: Geotemas (Madrid)

Resumo

During the Early Cretaceous, isolated carbonate platforms developed on tilted blocks bounded by listric faults in the Sou- thern Iberian Palaeomargin. One of them corresponds to the present Sierra de Bedmar-Jódar (Prebetic of Jaén). The Valan- ginian of this unit is represented by a marly limestone-marl rhythmite (Los Villares Fm). The top of this formation is an irregular surface covered by a laterally discontinuous lutitic red bed (25 cm maximum thickness). Above this red level, there are sandstones assigned to the base of Llopis Fm, which, by correlation, could be dated as late Barremian or early Aptian The uppermost part of the Los Villares Fm and the red level have been sampled to obtain geochemical and mineralogical data to investigate environmental changes. In the red level, there are kaolinite and illite, an enrichment in Fe, Al and Mn, and a reduction in the content of CaCO3 and in the Sr with respect to Los Villares Fm. The values of ẟ13C show variation from -2 ‰ in Los Villares Fm to close to -5 ‰ in the red level. The values of ẟ 18O shows range from -4 to -6 ‰. TOC values range between 0.2 to 0.5 %. Geochemical and field data seem to indicate that there was an emersion and erosion of the materials of the Los Villares Fm with development of incipient laterites. These processes were a consequence of a relative sea level fall linked to a tectonic extensional event.

Fonte de datos: Dialnet