Evaluación patrimonial de los afloramientos de "Ofitas" con estructuras en m in i-pillow de Cerro Pelado (Granada): nuevo indicio de vulcanismo triásico y metamorfismo alpino de las Zonas Externas Béticas

• E. Puga ^[1] ; M.A. Díaz Puga ^[2] ; M. Ruiz Montes ^[2] ; A. Díaz de Federico ^[1] ; D. Morata ^[3]
  1. [1] Instituto Andaluz de Ciencias de la Tierra

     Instituto Andaluz de Ciencias de la Tierra

     Granada, España

     
  2. [2] Instituto Geológico y Minero de España

     Instituto Geológico y Minero de España

     Madrid, España

     
  3. [3] Universidad de Chile

     Universidad de Chile

     Santiago, Chile

     

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• Localización: Geotemas (Madrid), ISSN 1576-5172, Nº. 6, 4, 2004 (Ejemplar dedicado a: VI CONGRESO GEOLÓGICO DE ESPAÑA (Zaragoza, 12-15 julio, 2004)), págs. 135-138
• Idioma: español
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• Resumen

  • A new ophite outcrop located at the boundary between the external and internal zones of the Betic Cordillera is described', with special reference to petrological and geochemical features. The outcrop belongs to the Triassic of Antequera and is currently being exploited for ballast material, despite some special geological values and peculiarities, which should demand its preservation: a) Mini-pillow structures which are not found elsewhere in any other ophite outcrop of the Betic external zones. The unequivocal volcanic nature of these structures has allowed dating the beginning of magmatism in the Betic external zones as Triassic in age instead of Jurassic, as had been generally accepted so far on the basis of the supposed intrusive character of all the ophite bodies;

    b) The higher metamorphism grade identified in this outcrop, compared to those located further from the boundary between the external and internal Betic zones: As remarked here, the Alpine metamorphism reaches greenschist facies conditions in the Cerro Pelado ophites, whilst only pumpellyite-actinolite facies conditions have been recognized at the metamorphic climax in other ophite outcrops studied to date in this region. This corroborates the idea that the Triassic of Antequera was probably subdued beneath the internal zones during one of the compressive stages of the Alpine orogeny