RT Book, Section
T1 Thrust and detachment systems in the Ordenes Complex(northwestern Spain): Implications for theVariscan-Appalachian geodynamics.
A1 Martínez Catalán, José Ramón
A1 Díaz García, Florentino
A1 Arenas Martín, Ricardo
A1 Abati Gómez, Jacobo
A1 Castiñeiras García, Pedro
A1 González Cuadra, Pablo
A1 Gómez Barreiro, Juan
A1 Rubio Pascual, Francisco J.
A2 Martínez Catalán, José Ramón
A2 Hatcher, Robert D.
A2 Arenas Martín, Ricardo
A2 Díaz García, Florentino
AB The allochthonous complexes of northwestern Iberia consist of a pile of units of Gondwanan and peri-Gondwanan provenance, and include oceanic lithosphere. The units are classiµed into upper, intermediate (ophiolitic), and basal. We present a dettailed geological map and sections across the Ordenes Complex, together with a brief description of its units and a discussion of its structures. In the upper units, two complete cycles of burial and exhumation have been identiµed. The first cycle, of Early Ordovician age, records a convergent plate margin, possibly in a peri-Gondwanan domain. The second is Variscan, and the structural evollution of the three groups of allochthonous units re×ects progressive accretion to an acctive orogenic wedge. Continuous understacking of continental and oceanic fragments  toward the west began with the upper units and ended with the basal units. The latter represent the outermost margin of Gondwana, and their subduction marked the closure of the intervening ocean, and the change from subduction to a collisional regime. Terrane accretion took place in the Devonian and, during the Late Devonian and the Carboniferous, the deformation progressed inboard of the Gondwana margin. Variscan emplacement of the allochthonous units occurred in two successive thrusting episodes. The µrst placed the basal units over the sedimentary cover of the Gondwana margin in what seems to follow a normal sequence of thrusting. The second carried the upper and ophiolitic units on top of the previous nappe pile and has an out-of-sequence character. A possible correlation of the Early Ordovician convergence, early Variscan accretion, subsequent oceanic closure, continent-continent collision, and renewed thrust activity during the late Carboniferous in northwestern Iberia is established with the Taconian, Acadian, and Alleghanian orogenies in the Appalachians.
PB Geological Society of America
SN 9780813723648
SN 0072-1077
YR 2002
FD 2002
LK https://hdl.handle.net/20.500.14352/61077
UL https://hdl.handle.net/20.500.14352/61077
LA eng
NO Dirección General de Investigación Científica y Técnica
NO Dirección General de Enseñanza Superior e Investigación Científica
DS Docta Complutense
RD 8 abr 2025