RT Journal Article
T1 Late Cambrian magmatic arc activity in peri-Gondwana:geochemical evidence from metagranitoid rocks of the BasalAllochthonous Units of NW Iberia
A1 Andonaegui Moreno, María Del Pilar
A1 Abati Gómez, Jacobo
A1 Díez Fernández, Rubén
AB The North African section of the Gondwana margin was the site of voluminous, arc-related magmatism during the Late Neoproterozoic (Avalonian–Cadomian orogen). The lower (and older) metasedimentary sequence that constitutes the Basal Units of the Allochthonous Complexes of NW Iberia was deposited in that setting. In these units, sedimentation was followed by the intrusion of tonalites and granodiorites in the late Cambrian (ca. 493–489Ma). In the Late Paleozoic, the collision of Gondwana and Laurussia (Variscan orogeny) deformed and metamorphosed the whole ensemble. New whole rock geochemical analysis performed in seven samples of metatonalites and fourteen samples of metagranodiorites are characterized by: i) slight enrichment in incompatible elements (Rb, Ba, Th, U), ii) negative anomalies in Nb, Ta, P, and Ti, and iii) negative anomalies in Eu. These chemical features are in agreement with a subduction-related setting for the genesis of both types of magma, which is also supported by chemical discrimination using tectonic setting diagrams. Positive anomalies of Pb suggest a crustal component. The new geochemical data reveal that the convergent orogen that ruled the paleogeography of the Gondwana periphery during the Neoproterozoic (Cadomian orogen) remained active beyond the Neoproterozoic-Cambrian transition, up to at least late Cambrian times.
PB http://revistes.ub.edu/index.php
SN 1695-6133
YR 2017
FD 2017-10
LK https://hdl.handle.net/20.500.14352/18553
UL https://hdl.handle.net/20.500.14352/18553
LA eng
NO Ministerio de Economía y Competitividad (MINECO)
DS Docta Complutense
RD 10 abr 2025