The Triassic alkaline dolerites of the Valacloche-Camarena Area (SE-Iberian Chain, Terual): Geodynamic implications

• Autores: Enrique Arranz Yagüe, Marceliano Lago San José, Ramon Vaquer Navarro, Andrés Gil Imaz, Andrés Pocoví Juan, Carlos Galé Bornao
• Localización: Estudios geológicos, ISSN 0367-0449, Vol. 56, Nº 5-6, 2000, págs. 211-228
• Idioma: inglés
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• Resumen

  • The dolerite sills outcropping in the Valacloche-Camarena area (SE Iberian Chain), are the expression of an alkaline magmatism, emplaced in Keuper facies sedimentary rocks. Their pre-Hettangian age is deduced from the development of fluidality structures at the top of the sills together with the very low grade contact metamorphism of the host rocks. A differentiation trend, representad by two rock-types, with variable Ti-augite content, is confirmed by geochemical data (REE). The alkaline composition of this magmatism is close to that of the OIB type. Crust-derived enclaves (metapelites and granitoids) are common in these sills, suggesting that magma ascent took place through a fracture system, related to a distensive tectonic regime, that affected different levels of the crust. This magmatism was one of the expressions of the triassic rifting events that are well representad in the SE border of the Iberian Chain