@misc{10481/78971,
year = {2022},
month = {11},
url = {https://hdl.handle.net/10481/78971},
abstract = {This study presents a new geochemical, petrological, and geochronological U-Pb dataset from Ediacaran metabasites
and associated rocks of the Canigó and Cap de Creus massifs, Eastern Pyrenees. Metabasites are composed of calcic
amphibole + plagioclase + chlorite + epidote ± quartz plus titanite + apatite + ilmenite ± biotite ± rutile as accessory
phases and show relict igneous textures. Peak pressure-temperature determinations share common conditions, ranging
452-482ºC and 5.2-7.7kbar, which suggest Barrovian-type metamorphism, most likely related to a collisional setting. The
metabasites correspond to evolved basaltic rocks (Mg#<0.55) with moderate TiO2 content (up to 2.08wt.%) and relatively
low Cr (43-416ppm). The rocks are moderately enriched in Light Rare Earth Elements (LREE) relative to Heavy Rare
Earth Elements (HREE) (average (La/Lu)n of 2.7) and the N-MORB normalized multi-element patterns show negative
slopes, with prominent negative Nb anomalies ((Nb/La)NMORB=0.33–0.78). These variations are akin to island arc tholeiites
generated in back-arc basins and to other metabasites described in the Eastern Pyrenees with a putative Ediacaran age,
and they differ from the Ordovician tholeiitic metabasites from the Canigó massif, which derived from a contaminated
E-MORB source. The positive ƐNd(T) values (0.82-3.05) of the studied metabasites preclude a notable contribution from
an older continental crust. Detrital zircon U-Pb dating Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry
(LA-ICP-MS) of one chlorite-rich schist sample in contact with the metabasites from the Canigó massif yielded a main
peak at ca. 632Ma and apparent maximum age of deposition at ca. 550Ma. We argue that the Cadomian metabasites
from the Pyrenees formed during back-arc extension in the continental margin of Gondwana and were later affected by
(probably early Variscan) medium-P metamorphism before the Low-Pressure High-Temperature (LP-HT) metamorphism
classically described in the Pyrenees.},
organization = {Spanish Government	CGL2017-87631-P	
PGC2018-093903-B-C22},
organization = {Ministerio de Ciencia, Innovacion y Universidades/Agencia Estatal de Investigacion/Fondo Europeo de Desarrollo Regional, Union Europea},
organization = {Margarita Salas grant},
organization = {Universitat de Barcelona},
organization = {Ministerio de Universidades/NextGenerationEU/PRTR/Plan de recuperacion, transformacion y resiliencia},
publisher = {Universitat de Barcelona},
keywords = {Pan-African},
keywords = {Cadomian},
keywords = {Inherited zircon},
keywords = {Peri-Gondwanan},
keywords = {Iberian Massif},
title = {Cadomian metabasites of the Eastern Pyrenees revisited},
doi = {10.1344/GeologicaActa2022.20.13},
author = {Pujol Solà, Núria and Román Alpiste, Manuel J.},
}