Chapitre D'ouvrage Année : 2026

Cadomian Cycle in the Pyrenees

Résumé

The Ediacaran‒Terreneuvian stratigraphic framework and magmatic activity recorded in the Eastern Pyrenees is updated and summarized in this chapter. The age of the unfossiliferous Canaveilles Group is constrained by radiometric data of their interbedded tuffs (ca. 577 to 532 Ma). The group is subdivided into the Nyer (monotonous green and grey metapelites bearing marble interbeds), Olette (monotonous green metapelites) and Pic de la Clape (volcanosedimentary) formations. The latter comprises three members: (i) the Fabert metavolcanics, (ii) the Finestrelles volcaniclastic breccias and tuffaceous litharenites, and (iii) the bedded to massive carbonates of the Puig Sec Member. Based on the northward wedging of the Pic de la Clape volcanosedimentary complex, a S‒N trending, proximal to distal (deepening) gradient can be interpreted, with subaerial conditions recorded in the peritidal carbonates at Coll d’Ares (southern slope of the Canigó massif) and monotonous (nearly undifferentiable) metapelites across the entire Canaveilles Group on the Conflent area (northern slope of the Canigó massif). Three Ediacaran magmatic pulses are differentiated: (i) metabasites (metagabbros and metabasalts to metabasaltic andesites; ca. 630? ‒550 Ma) interbedded in the Nyer and lower part of the Olette formations; (ii) granitic orthogneisses (ca. 560‒533 Ma); and (iii) metavolcanic intermediate rocks (ca. 577‒542 Ma) mainly located in the upper part of the Nyer Formation and representing the main thickness of the Fabert and Finestrelles members. The Cadomian activity, lasting at least 40 m.y. (577 to 532 Ma), is characterized by calc-alkaline features reflecting arc settings with distinct crustal contamination at its source, although the onset of the Cadomian arc magmatism could be probably extended to the earliest Ediacaran (630 Ma).

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Dates et versions

hal-05625432 , version 1 (18-05-2026)

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Citer

J. Álvaro, Josep Maria Casas, S. Clausen, Maxime Padel, N. Pujol-Solà, et al.. Cadomian Cycle in the Pyrenees. The Geology of Iberia: A Geodynamic Approach, Springer Nature Switzerland, pp.287-310, 2026, Regional Geology Reviews, 978-3-030-10398-9. ⟨10.1007/978-3-030-10398-9_13⟩. ⟨hal-05625432⟩
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