RT Book, Section
T1 Paleozoic ophiolites in the Variscan suture of Galicia(northwest Spain): Distribution, characteristics, and meaning
A1 Arenas Martín, Ricardo
A1 Martínez Catalán, José Ramón
A1 Sánchez Martínez, Sonia
A1 Díaz García, Florentino
A1 Abati Gómez, Jacobo
A1 Fernández Suárez, Javier
A1 Andonaegui Moreno, María Del Pilar
A1 Gómez Barreiro, Juan
A2 Hatcher, Robert D.
A2 Carlson, Marvin P.
A2 McBride, John H.
A2 Martínez Catalán, José Ramón
AB Allochthonous ophiolitic units in the northwestern Iberian Massif are remnants of peri-Gondwanan Paleozoic oceans sandwiched among other exotic terranes of continental and volcanic-arc derivation. All these terranes defi ne an intricate suture zone that marks the convergence and collision between Laurussia and Gondwana. The suture is defi ned by three different ophiolitic ensembles: upper ophiolitic units, lower ophiolitic units, and the Somozas mélange. The lower ophiolitic units were derived from an alternation of basalts and sediments intruded by gabbros and scarce granitoids, and they formed during the opening of a marginal basin, the Galician ocean, during Late Cambrian to Early Ordovician time. This ocean was created as a back arc by the severance of a volcanic arc that had developed at the northern margin of Gondwana and formed part of the Rheic oceanic realm. The upper ophiolitic units formed during the Early Devonian from intraoceanic subduction in the early Paleozoic lithosphere of the Rheic Ocean. These suprasubduction ophiolites were formed just before the ocean closed, preceding the collision between Gondwana and Laurussia. The Somozas mélange appears in an anomalous position at the base of the Cabo Ortegal Complex. The ophiolites involved in this tectonic mélange represent an imbricate of highly dismembered oceanic lithosphere, slivers of subducted outer edge of the Gondwanan continental margin, and Paleozoic metasediments of the northern Gondwanan platform. The ophiolites might either record the development of a different peri-Gondwanan oceanic domain, or they might be equivalent to any of the other ophiolitic ensembles, and their anomalous structural position is simply a consequence of complex thrusting.
PB Geological Society of America
SN 9780813712000
YR 2007
FD 2007
LK https://hdl.handle.net/20.500.14352/53785
UL https://hdl.handle.net/20.500.14352/53785
LA eng
NO Ministerio de Ciencia y Tecnología
NO Ministerio de Educación y Ciencia
DS Docta Complutense
RD 26 ago 2024