Subduction and syn-collisional exhumation of a Paleozoic continental margin: an integrated study based on structures and P-T paths of the Basal Units in the Ordenes Complex (Galicia, Spain).

  1. Martínez Catalán, J.R. 1
  2. Arenas, R. 2
  3. Díaz García, F. 3
  4. Rubio Pascual, F.J. 4
  5. Abati, J. 2
  6. Marquínez, J. 3
  1. 1 Universidad de Salamanca
    info

    Universidad de Salamanca

    Salamanca, España

    ROR https://ror.org/02f40zc51

  2. 2 Universidad Complutense de Madrid
    info

    Universidad Complutense de Madrid

    Madrid, España

    ROR 02p0gd045

  3. 3 Universidad de Oviedo
    info

    Universidad de Oviedo

    Oviedo, España

    ROR https://ror.org/006gksa02

  4. 4 Instituto Geológico y Minero de España (IGME)
Zeitschrift:
Geogaceta

ISSN: 0213-683X

Datum der Publikation: 1996

Titel der Ausgabe: Comunicaciones presentadas en el IV Congreso Nacional de Geología, Alcalá de Henares, 1996

Nummer: 20

Seiten: 867-870

Art: Artikel

Andere Publikationen in: Geogaceta

Zusammenfassung

According to their metamorphic evolution, the Basal Units of the Galician Allochthonous Complexes are thought to represent a part of the margin of the Paleozoic Gondwana, subducted at the onset of the Variscan Orogeny. Variations in the P-T conditions of the first HP metamorphic event along the units suggest an important westward component for the direction of sucduction. Subsequent underthrusting of more continental material blocked the subduction and triggered the ascent and exhumation of the Basal Units whereas the convergence continued. Compressional and extensional structures were synchronous or alternated in time and, together, induced the thinning and tapering of the orogenic wedge. The unroofing took place locally under an inverted temperature gradient, caused by a detachment which carried a part of the hot mantle wedge, above the subduction zone, over the subducted units.