RT Journal Article
T1 Variscan exhumation of a subducted Paleozoic continentalmargin: The basal units of the Ordenes Complex,Galicia, NW Spain
A1 Martínez Catalán, José Ramón
A1 Arenas Martín, Ricardo
A1 Díaz García, Florentino
A1 Rubio Pascual, Francisco J.
A1 Abati Gómez, Jacobo
A1 Marquínez, Jorge
AB A structural and metamorphic study was carried out in the basal units of the Ordenes Complex in Spain, thought to represent a subducted part of the Paleozoic margin of Gondwana. According to their metamorphic evolution, this part of the margin was subducted at the onset of the Variscan Orogeny, becoming part of an accretionary complex developed below a colliding element built previously. Variations in the PT conditions of the first high-pressure metamorphic event along the units indicate a polarity of the subduction to the west. Subsequent underthrusting of more continental material blocked the subduction and triggered the ascent and exhumation of the basal units, whereas the convergence continued. Recumbent folds and thrusts de ve loped along with successive normal detachments. Compressional and extensional structures were synchronous or alternated in time and together induced the thinning and tapering of the orogenic wedge and its lateral spreading. 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.
PB American Geophysical Union
SN ISSN: 0278-7407 ; ESSN: 1944-9194
YR 1996
FD 1996
LK https://hdl.handle.net/20.500.14352/58114
UL https://hdl.handle.net/20.500.14352/58114
LA eng
NO DGICYT (Spain).
DS Docta Complutense
RD 23 jul 2024