Evolución tectonotermal asociada con extensión a escala corticalel ejemplo hercínico del domo gneísico del Tormes (NO Salamanca, Macizo Ibérico)

  1. Escuder Viruete, J.
  2. Arenas, R.
  3. Martínez Catalán, J. R.
Revista:
Cadernos do Laboratorio Xeolóxico de Laxe: Revista de xeoloxía galega e do hercínico peninsular

ISSN: 0213-4497

Any de publicació: 1994

Número: 19

Pàgines: 273-304

Tipus: Article

Altres publicacions en: Cadernos do Laboratorio Xeolóxico de Laxe: Revista de xeoloxía galega e do hercínico peninsular

Resum

The tectonothermal Variscan evolution of the Tormes Gneiss Dome is controlled by a subhorizontal ductile shear zone of crustal scale and extensional characteristics, that induced a quick exhumation of the deep parts of the metamorphic complex during crustal thinning. The shearing affected a broad band of metamorphic rocks but, as the temperature decreased, became progressively concentrated in a low-grade ductile detachment that separates two distinct units, characterized by their lithology and different tectonothermal evolution. Kinematic indicators in non-coaxial fabrics show a displacement of the hangingwall to the SE, i. e., parallel to the trend of the foldbelt. The subhorizontal shearing is related to the extensional collapse of the variscan crust, previously thickened during the collision tectonics.