Shifts in the Ediacaran to Lower Ordovician sedimentary zircon provenances of Northwest Gondwana: the Pyrenean files (original) (raw)

Authors

DOI:

https://doi.org/10.1344/GeologicaActa2022.20.14

Keywords:

Orogeny, Rift, Paleogeography, Pyrenees, Detrital zircon, Godwana

Abstract

Detrital zircon grains from Cambrian–Lower Ordovician sandstones and quartzites sampled in the Pyrenees were dated by LA-ICPMS in order to assess their provenance sources. Resulting age distributions are compared to other available datasets from neighbouring margins, such as Morocco, the Iberian Peninsula, southern France and Sardinia. Kolmogorov-Smirnov (K-S) test and Crystallization Age-Depositional Age (CA-DA) diagrams were used to compare zircon populations estimating their possible correlation with the arc/rift/drift geodynamic evolution of the northwestern Gondwana margin. During Terreneuvian times, zircon populations allowed the distinction of i) a southwesternmost edge (Anti-Atlas-Ossa-Morena Rift) mostly influenced by Panafrican and Anti-Atlasian sources (ca. 0.63–0.54), ii) a northeasternmost edge (Sardinia) recording the influence of the Saharan Metacraton and the Arabian Nubian Shield, with an distinct Stenian–Tonian shift (ca. 1.25–0.85Ga) and iii) an intermediate palaeogeographic transect, where lies the Central-Iberian, West Asturian-Leonese and Cantabrian Zones, the Montagne Noire and the Pyrenees sharing similar populations and a chronologically progressive influence from Anti-Atlasian/Panafrican to Saharan Metacraton/Arabian Nubian Shield sources. This gradual modification in zircon percentage populations supports similar trends based on climatically sensitive indicators, biogeographic patterns of Cambrian Epoch 2 archaeocyathan and microfossil assemblages, and laterally correlatable episodes of carbonate production, all of them pointing to a Cambrian setting for the Pyrenean Basin between the Montagne Noire (Occitan Domain) and the Sardinian margins of NW Gondwana. The Terreneuvian zircon patterns recorded in the Pyrenees gradually evolved from Cambrian Epoch 2 to Early Ordovician times, reflecting the geodynamic
evolution from Panafrican and Cadomian arc-related to rift-dominant conditions. During Furongian and Ordovician times, the relative percentage of zircon populations led to a more spread age curve, characteristic of extensional settings and pointing to rift (passive margin) conditions.

References

Allen, P.A., Allen, J.R., 2005. Basin Analysis. Principles and Applications. Cambridge, Blackwell Scientific Publications, 562pp.

Altumi, M.M., Elicki, O., Linnemann, U., Hofmann, M., Sagawe, A., Gärtner, A., 2013. U-Pb LA-ICP-MS detrital zircon ages from the Cambrian of Al Qarqaf Arch, central-western Libya: provenance of the West Gondwanan sand sea at the dawn of the early Palaeozoic. Journal of African Earth Sciences, 79, 74–97.

Álvaro, J.J., Bauluz, B., Clausen, S., Devaere, L., Imaz, A.G., Monceret, E., Vizcaïno, D., 2014a. Stratigraphy of the Cambrian–Lower Ordovician volcanosedimentary complexes in the northern Montagne Noire, France. Stratigraphy, 11, 83–96.

Álvaro, J.J., Benziane, F., Thomas, R., Walsh, G.J., Yazidi, A., 2014b. Neoproterozoic–Cambrian stratigraphic framework of the Anti-Atlas and the Ouzellagh promontory (High Atlas), Morocco. Journal of African Earth Sciences, 98, 1–15.

Álvaro, J.J., Colmenar, J., Monceret, E., Pouclet, A., Vizcaïno, D., 2016. Late Ordovician (post–Sardic) rifting branches in the North Gondwanan Montagne Noire and Mouthoumet massifs of southern France. Tectonophysics, 681, 111–123.

Álvaro, J.J., Sánchez-García, T., Puddu, C., Casas, J.M., DíezMontes, A., Liesa, M., Oggiano, G., 2020. Comparative geochemical study on Furongian–earliest Ordovician (Toledanian) and Ordovician (Sardic) felsic magmatic events in south-estern Europe: underplating of hot mafic magmas linked to the opening of the Rheic Ocean. Solid Earth, 11, 2377–2409.

Álvaro, J.J., Casas, J.M., Quesada, C., 2021. Reconstructing the pre–Variscan puzzle of Cambro–Ordovician basement rocks in the southwestern European margin of Gondwana. In: Murphy, J.B., Strachan, R.A., Quesada, C. (eds.). Pannotia to Pangaea: Neoproterozoic and Paleozoic Orogenic Cycles in the Circum-Atlantic Region. Geological Society, London, Special Publications 503, 531–562

Avigad, D., Kolodner, K., McWillians, M., Persing, H., Weissbroad, T., 2003. Origin of northern Gondwana Cambrian sandstone revealed by detrital zircon SHRIMP. Geology, 31, 227-230.

Avigad, D., Gerde, A., Morag, N., Bechstädt, T., 2012. Coupled U-Pb-Hf of detrital zircons of Cambrian sandstones from Morocco and Sardinia: implications for provenance and Precambrian crustal evolution of North Africa. Gondwana Research, 21, 690–703.

Avigad, D., Rossi, Ph., Gerdes, A., Abdo, A., 2018. Cadomian metasediments and Ordovician sandstone from Corsica: detrital zircon U-Pb-Hf constrains on their provenance and paleogeography. International Journal of Earth Sciences, 107, 2803–2818.

Ballèvre, M., Le Goff, E., Hébert, R., 2001. The tectonothermal evolution of the Cadomian belt of northern Britany, France: a Neoproterozoic volcanic arc. Tectonophysics, 331, 19–43.

Ballèvre, M., Bosse, V., Ducassou, C., Pitra, P., 2009. Palaeozoic history of the Armorican Massif: models for the tectonic evolution of the suture zones. Comptes Rendus Geoscience, 341, 174–201.

Ballouard, C., Poujol, M., Zeh, A., 2018. Multiple crust reworking in the French Armorican Variscan belt: implication for the genesis of uranium-fertile leucogranites. International Journal of Earth Sciences,107, 2317–2336.

Barnolas, A., Chiron, J.C., 1996. Synthèse géologique et géophysique des Pyrénées. Tome 1: Cycle hercynien. OrléansMadrid, Bureau de Recherche Géologique et Minière – Instituto Tecnológico y Geominero de España, 729pp.

Be’eri-Shlevin, Y., Eyal, M., Eyal, Y., Whitehouse, M.J., Livinovsky, B., 2012. The Sa’al volcano-sedimentary complex (Sinai, Egypt): a latest Mesoproterozoic volcanic arc in the northern Arabian Nubian Shield. Geology, 40, 403–406.

Bernard, J., Couëffé, R., Blein, O., Vic, G., Buscail, F., Tchokona Seuwui, D., Wongolo Djombol, M.H., Tucker, R., Cagnard, F., Duron, J., Martelet, G., Bailly, L., Chevillard, M., Colin, S., Chabot, L., Gutierrez, T., Lahaye, Y., Anaba Fotze, Q.M., Eno-Tabi Lobe Makia, G., Ndapeh Ndellejong, B., Essomba, Y.H., 2021, Carte géologique du Cameroun à 1/200 000 – Feuilles Batouri (NB-33-III), Betare-Oya (NB33-IX), Meiganga (NB-33-XV), Belel (NB-33-XXI), ReyBouba (NC-33-III). Ministère des Mines, de l’Industrie et du Développement technologique du Cameroun, Yaoundé, Notice explicative, 224pp.

Blein, O., Baudin, T., Soulaimani, A., Cocherie, A., Chèvremont, P., Admou, H., Ouanaimi, H., Hafid, A., Razin, P., Bouadbelli, M., Roger, J., 2014a. New geochemical, geochronological and structural constraints on the Ediacaran evolution of the south Sirwa, Agadir-Melloul and Iguerda inliers, Anti-Atlas, Morocco. Journal of African Earth Sciences, 98, 47–71.

Blein, O., Baudin, T., Chèvremont, Ph., Soulaimani, A., Admou, H., Gasquet, D., Cocherie, A., Egal, E., Youbi, N., Razin, Ph., Bouabdelli, M., Gombert, Ph., 2014b. Geochronological constraints on the polycyclic magmatism in the Bou Azzer-El Graara inlier (Anti-Atlas, Morocco). Journal of African Earth Sciences, 99, 287–306.

Caby, R., 2003. Terrane assembly and geodynamic evolution of central-western Hoggar: a synthesis. Journal of African Earth Sciences, 37, 133–159.

Casas, J.M., Murphy, J.B., 2018. Unfolding the arc: the use of preorogenic constraints to assess the evolution of the Variscan belt in Western Europe. Tectonophysics, 736, 47–61.

Cass, J.M., Palacios, T., 2012. First biostratigraphical constraints on the pre–Upper Ordovicians sequences of the Pyrenees based on organic-walled microfossils. Comptes Rendus Geoscience, 344, 50–56.

Casas, J.M., Castiñeiras, P., Navidad, M., Liesa, M., Carreras, J., 2010. New insights into the Late Ordovician magmatism in the Eastern Pyrenees: U-Pb SHRIMP zircon data from the Canigó massif. Gondwana Research, 17, 317–324.

Casas, J.M., Navidad, M., Castiñeiras, P., Liesa, M., Aguilar, C., Carreras, J., Hofman, M., Gärtner, A., Linnemann, U., 2015. The Late Neoproterozoic magmatism in the Ediacaran series of the Eastern Pyrenees: new ages and isotope geochemistry. International Journal of Earth Sciences, 104, 909–925.

Castiñeiras, P., Navidad, M., Liesa, M., Carreras, J., Casas, J.M., 2008. U-Pb zircon ages (SHRIMP) for Cadomian and Lower Ordovician magmatism in the Eastern Pyrenees: new insights in the pre–Variscan evolution of the northern Gondwana margin. Tectonophysics, 46, 228–239.

Cawood, P.A., Hawkesworth, C.J., Dhuime, B., 2012. Detrital zircon record and tectonic setting. Geology, 40, 875–878.

Cochelin, B., Lemirre, B., Denèle, Y., De Saint Blanquat, M., Lahfid, A., Duchêne, S., 2018. Structural inheritance in the Central Pyrenees: the Variscan to Alpine tectonometamorphic evolution of the Axial Zone. Journal of the Geological Society, 175, 336–351.

Cocherie, A., Baudin, T., Autran, A., Guerrot, C., Fanning, M., Laumonier, B., 2005. U-Pb zircon (ID-TIMS and SHRIMP) evidence for the early Ordovician intrusion of metagranites in the late Proterozoic Canaveilles Group of the Pyrenees and the Montagne Noire (France). Bulletin de la Société géologique de France, 176, 269–282.

Couzinié, S., Laurent, O., Chelle-michou, C., Bouilhol, P., Paquette, J.L., Gannoun, A.M., Moyen, J.F., 2019. Detrital zircon U-PbHf systematics of Ediacaran metasediments from the French Massif Central: consequences for the crustal evolution of the north Gondwana margin. Precambrian Research, 324, 269–284.

Deloule, E., Alexandrov, P., Cheilletz, A., Laumonier, B., Barbey, P., 2002. In situ U-Pb zircon ages for Early Ordovician magmatism in the eastern Pyrenees, France: the Canigou orthogneisses. International Journal of Earth Sciences, 91, 398–405.

Denèle Denèle, Y., Barbey, P., Deloule, E., Pelleter, E., Olivier, Ph., Gleizes, G., 2009. Middle Ordovician U-Pb age of the Aston and Hospitalet orthogneissic laccoliths: their role in the Variscan evolution of the Pyrenees. Bulletin de la Société géologique de France, 180(3), 209–216.

Dias, R., Ribeiro, A., Romão, J., Coke, C., Moreira, N., 2016. A review of the arcuate structures in the Iberian Variscides; constraints and genetic models. Tectonophysics, 681, 170–194.

Dickinson, W.R., Gehrels, G.E., 2009. Use of U–Pb ages of detrital zircons to infer maximum depositional ages of strata: a test against a Colorado Plateau Mesozoic database. Earth and Planetary Science Letters, 288, 115–125.

Drost, K., Gerdes, A., Jeffries, T., Linnemann, U., Storey, C., 2011. Provenance of Neoproterozoic and early Paleozoic silicicastic rocks of the Tepla-Barrandian unit (Bohemian Massif): evidence from U-Pb detrital zircon ages. Gondwana Research, 19, 213–231.

Faure, G., Mensing, T.M., 2005. Isotopes: principles and applications. Wiley, Hoboken, 928pp.

Fernández-Suárez, J., Gutiérrez-Alonso, G., Jenner, G.A., Tubrett, M.N., 2000. New ideas on the Proterozoic–Early Palaeozoic evolution of NW Iberia: insights from U-Pb detrital zircon ages. Precambrian Research, 102, 185–206.

Fernández-Suárez, J., Gutiérrez-Alonso, G., Pastor-Galán, D., Hofmann, M., Murphy, J.B., Linnemann, U., 2014. The Ediacaran–Early Cambrian detrital zircon record of NW Iberia: possible sources and paleogeographic constraints. International Journal of Earth Sciences, 103, 1335–1357.

Gehrels, G., 2014. Detrital zircon U-Pb geochronology applied to tectonics. Annual Review of Earth and Planetary Sciences, 42, 127–149.

Gutiérrez-Alonso, G., Fernández-Suarez, J., Jeffries, T.E., Jenner, G.A., Tubrett, M.N., Cox, R., Jackson, S.E., 2003. Terrane accretion and dispersal in the northern Gondwana margin. An Early Paleozoic analogue of a long-lived active margin. Tectonophysics, 365, 221–232.

Gutiérrez-Alonso, G., Fernández-Suarez, J., Pastor-Galán, D., Johnston, S.T., Linnemann, U., Hofmann, M., Shaw, J., Colmenero, J.R., Hernández, P., 2015. Significance of detrital zircons in Siluro–Devonian rocks from Iberia. Journal of the Geological Society, 172, 309–322.

Guynn, J., Gehrels, G., 2010. Comparison of detrital zircon age distributions using the K-S test. Last accessed: April 2010 Website: https://sites.google.com/a/laserchron.org/laserchron/

Henderson, B.J., Collins, W.J., Murphy, J.B., Gutiérrez-Alonso, G., Hand, M., 2016, Gondwanan basement terranes of the Variscan–Appalachian orogeny: Baltican, Saharan and West African hafnium isotopes fingerprints in Avalonia, Iberia and the Armorican Terranes. Tectonophysics, 681, 278–304.

Jackson, S.E., Pearson, N.J., Griffin, W.L., Belousova, E.A., 2004. The application of laser-ablation-inductively coupled plasmamass spectrometry to in situ U-Pb zircon geochronology. Chemical Geology, 211, 47–69.

Kroner, A., Stern, R.J., 2005. Pan-African orogeny. Encyclopedia of Geology, 1, 1–12.

Kydonakis, K., Kostopoulos, D., Poujol, M., Brun, J.P., Papanikolaou, D., Paquette, J.L., 2014. The dispersal of the Gondwana super-fan system in the eastern Mediterranean: new insights from detrital zircon geochronology. Gondwana Research, 25, 1230–1241.

Laumonier, B., Abad, A., Alonso, J.L., Baudelot, S., Bessière, G., Besson, M., Bouquet, C., Bourrouilh, R., Brula, P., Carreras, J.,

Centène, A., Courjault-Radé, R., Courtessole, R., Fauconnier, D., García-Sansegundo, J., Guitard, G., Moreno-Eiris, E., Perejón, A., Vizcaïno, D., 1996. Cambro–Ordovicien. In: Barnolas, A., Chiron, J.C. (eds.). Synthèse géologique et géophysique des Pyrénées. Tome 1: Cycle hercynien. OrléansMadrid, Bureau de Recherche Géologique et Minière – Instituto Tecnológico y Geominero de España, 729pp.

Laumonier, B., Autran, A., Barbey, P., Cheilletz, A., Baudin, T., Cocherie, A., Guerrot, C., 2004. Conséquences de l’absence de socle cadomien sur l’âge et la signification des séries pré–varisques (anté–Ordovicien supérieur) du sud de la France (Pyrénées, Montagne Noire). Bulletin de la Société géologique de France, 175, 105–117.

Laumonier, B., Calvet, M., Wiazemsky, M., Barbey, P., Marignac, C., Lambert, J., Lenoble, J.L., 2015. Notice explicative de la Carte géologique de la France (1/50.000), feuille Céret (1096). Bureau de Rercherche Géologique et Minière, Orléans.

Lemirre, B., Cochelin, B., Duchene, S., de Saint Blanquat, M., Poujol, M., 2019. Origin and duration of late orogenic magmatism in the foreland of the Variscan belt (Lesponne - Chiroulet - Neouvielle area, French Pyrenees). Lithos, 336, 183–201.

Liégeois, J.P., Latouche, L., Boughara, M., Navez, J., Guiraud, M., 2003. The LATEA metacraton (Central Hoggar, Tuareg Shield, Algeria): behaviour of an old passive margin during the Pan-African orogeny. Journal of African Earth Sciences, 37, 161–190.

Liesa, M., Carreras, J., Castiñeiras, P., Casas, J.M., Navidad, M., Vila, M., 2011. U-Pb zircon of Ordovician magmatism in the Albera Massif (Eastern Pyrenees). Geologica Acta, 9(1), 93–101.

Linnemann, U., Gerdes, A., Drost, K., Buschmann, B., 2007. The continuum between Cadomian Orogenesis and opening of the Rheic Ocean: constraints from LA-ICP-MS U-Pb zircon dating and analysis of plate-tectonic setting (Saxo-Thuringian Zone, NE Bohemian massif, Germany). In: Linnemann, U., Nance, D., Kraft, P., Zulauf, G. (eds.). The Evolution of the Rheic Ocean: from Avalonian–Cadomian Active Margin to Alleghenian–Variscan Collision. Geological Society of America, 423 (Special Papers), 423, 61–96.

Linnemann, U., Pereira, F., Jeffries, T.E., Drost, K., Gerdes, A., 2008. The Cadomian Orogeny and the opening of the Rheic Ocean: the diacrony of geotectonic processes constrained by LA-ICP-MS U-Pb zircon dating (Ossa-Morena and Saxo -Thuringian Zones, Iberian and Bohemian Massifs). Tectonophysics, 461, 21–43.

Linnemann, U., Ouzegane, K., Drareni, A., Hofmann, M., Becker, S., Gärtner, A., Sagawe, A., 2011. Sands of West Gondwana: an archive of secular magmatism and plate interactions – a case study from the Cambro–Ordovician section of the Tassili Ouan Ahaggar (Algerian Sahara) using U–Pb LA-ICP-MS detrital zircon ages. Lithos, 123, 188–203.

Linnemann, U., Gerdes, A., Hofmann, M., Marko, L., 2014. The Cadomian Orogen: Neoproterozoic to Early Cambrian crustal

growth and orogenic zoning along the periphery of the West African Craton – Constraints from U-Pb zircon ages and Hf isotopes (Schwarzburg Antiform, Germany). Precambrian Research, 244, 236–278.

Manzotti, P., Poujol, M., Ballèvre, M., 2015. Detrital zircon in blueschist-facies metaconglomerates: implications for the Early Permian palaeo-topography of the Western Alps. International Journal of Earth Sciences, 104, 703–731.

Margalef, A., Castiñeiras, P., Casas, J.M., Navidad, M., Montserrat, L., Linnemann, U., Hofmann, M., Gärtner, A., 2016. Detrital

zircons from the Ordovician rocks of the Pyrenees: geochronological constraints and provenance. Tectonophysics, 681, 124–134.

Martínez, F.J., Iriondo, A., Dietsch, C., Aleinikoff, J.N., Peucat, J.J., Cirès, J., Reche, J., Capdevila, R., 2011. U-Pb SHRIMPRG zircon ages and Nd signature of lower Paleozoic riftingrelated magmatism in the Variscan basement of the Eastern Pyrenees. Lithos, 127, 10–23.

Martínez Catalán, J.R., Arenas, R., Díaz García, F., González Cuadra, P., Gómez-Barreiro, J., Abati, J., Castiñeiras, P., Fernández-Suárez, J., Sánchez Martínez, S., Andonaegui, P., González Clavijo, E., Díez Montes, A., Rubio Pascual, F.J., Valle Aguado, B., 2007. Space and time in the tectonic evolution of the northwestern Iberian Massif: implications for the Variscan belt. In: Hatcher, R.D.Jr., Carlson, M.P., McBride, J.H., Martínez Catalán, J.R. (eds.). 4-D Framework of Continental Crust. Geological Society of America, 200 (Memoirs), 403–423.

Meert, J.G., 2003. A synopsis of events related to the assembly of eastern Gondwana. Tectonophysics, 362, 1–40.

Meinhold, G., Morton, A.C., Fanning, C.M., Frei, D., Howard, J.P., Phillips, R.J., Strogen, D., Whitham, A.G., 2011. Evidence from detrital zircons for recycling of Mesoproterozoic and Neoproterozoic crust recorded in Paleozoic and Mesozoic sandstones of southern Libya. Earth and Planetary Science Letters, 312, 164–175.

Meinhold, G., Morton, A.C., Avigad, D., 2013. New insights into peri-Gondwana paleogeography and the Gondwana super-fan system from detrital zircon U-Pb ages. Gondwana Research, 23, 661–665.

Mezger, J., Gerdes, A., 2016. Early Variscan (Visean) granites in the core of central Pyrenean gneiss domes: implications from. laser ablation U-Pb and Th-Pb studies. Gondwana Research, 29, 181–198.

Murphy, J.B., Keppie, J.D., Dostal, J., Nance, R.D., 1999. Neoproterozoic–early Paleozoic evolution of Avalonia. Geological Society of America, 336 (Special Papers), 253–266.

Murphy, J.B., Pisarvesky, S.A., Nance, R.D., Keppie, J.D., 2004. Neoproterozoic–Early Paleozoic evolution of peri-Gondwana terranes: implications for Laurentia-Gondwana connections. International Journal of Earth Sciences, 93, 659–682.

Murphy, J.B., Pisarvesky, S.A., Nance, R.D., 2013. Potential geodynamic relationships between the development of peripheral orogens along the northern margin of Gondwana and the amalgamation of West Gondwana. Mineralogy and Petrology, 107, 635–650.

Nance, D.R., Murphy, J.B., Keppie, J.D., 2002. A Cordilleran model for the evolution of Avalonia. Tectonophysics, 352, 11–31.

Nance, R.D., Murphy, J.B., Strachan, R.B., Keppie, J.D., GutiérrezAlonso, G., Fernández-Suárez, J., Quesada, C., Linnemann, U., D’lemos, R., Pisarevsky, S.A., 2008. Neoproterozoic–early Palaeozoic tectonostratigraphy and palaeogeography of the peri-Gondwanan terranes: Amazonian v. West African connections. In: Ennih, N., Liégeois, J.P. (eds.). The Boundaries of the West African Craton. London, The Geological Society, 297 (Special Publication), 345–383.

Padel, M., Clausen, S., Álvaro, J.J., Casas, J.M., 2017a. Review of the Ediacaran–Lower Ordovician (pre–Sardic) stratigraphic framework of the Eastern Pyrenees, southwestern Europe. Geologica Acta, 16(4), 339–355.

Padel, M., Álvaro, J.J., Clausen, S., Guillot, F., Poujol, M., Chichorro, M., Monceret, E., Pereira, M.F., Vizcaïno, D., 2017b. U-Pb

laser ablation ICP-MS zircon dating across the Ediacaran–Cambrian transition of the Montagne Noire, southern France.

Comptes Rendus Geoscience, 349, 380–390.

Padel, M., Álvaro, J.J., Casas, J.M., Clausen, S., Poujol, M., Sánchez-García, T., 2018. Cadomian volcanosedimentary complexes across the Ediacaran–Cambrian transition of the Eastern Pyrenees, southwestern Europe. International Journal of Earth Sciences, 107, 1579–1601.

Pastor-Galán, D., Gutiérrez-Alonso, G., Fernández-Suárez, J., Murphy, J.B., Nieto, F., 2013. Tectonic evolution of NW Iberia during the Paleozoic inferred from the geochemical record of detrital rocks in the Cantabrian Zone. Lithos, 182–183, 211–228.

Pereira, M.F., Solá, A.R., Chichorro, M., Lope, L., Gerdes, A., Silva, J.B., 2012. North-Gondwana assembly, break-up and paleogeography: U-Pb isotope evidence from detrital and igneous zircons of Ediacaran and Cambrian rocks of SW Iberia. Gondwana Research, 22, 866–881.

Perejón, A., Moreno-Eiris, E., Abad, A., 1994. Montículos de arqueociatos y calcimicrobios del Cámbrico inferior de Terrades, Gerona (Pirineo oriental, España). Boletín de la Real Sociedad Española de Historia Natural (Sección Geológica), 89, 55–95.

Pouclet, A., Álvaro, J.J., Bardintzeff, J.-M., Gil Imaz, A., Monceret, E., Vizcaïno, D., 2017. Cambrian–Early Ordovician volcanism

across the South Armorican and Occitan Domains of the Variscan Belt in France: Continental break-up and rifting of the northern Gondwana margin. Geosciences. Frontiers, 8, 25–64.

Shaw, J., Gutiérrez-Alonso, G., Johnston, S.T., Galán, D.P., 2014. Provenance variability along the Early Ordovician north Gondwana margin: paleogeographic and tectonic implications of U-Pb detrital zircon ages from the Armorican Quartzite of the Iberian Variscan belt. Geological Society of America Bulletin, 26, 702–719.

Sláma, J., Košler, J., Condon, D.J., Crowley, J.L., Gerdes, A., Hanchar, J.M., Horstwood, M.S.A., Morris, G.A., Nasdala, L., Norberg, N., Schaltegger, U., Schoene, B., Tubrett, M.N., Whitehouse, M.J., 2008. Plešovice zircon – a new natural reference material for U-Pb and Hf isotopic microanalysis. Chemical Geology, 249, 1–35.

Stampfi, G.M., von Raumer, J., 2008. The birth of the Rheic ocean – Early Paleozoic subsidence patterns and subsequent tectonic plate scenarios. Tectonophysics, 461, 9–20.

Stampfi, G.M., Hochard, C., Vérard, C., Wilhem, C., von Raumer, J., 2013. The formation of Pangea. Tectonophysics, 593, 1-19.

Stern, R.J., 1994. Arc assembly and continental collision in the Neoproterozoic east African orogen: implication for the consolidation of Gondwana. Annual Review of Earth and Planetary Sciences, 22, 319–351.

Talavera, C., Montero, P., Martínez Poyatos, D., Williams, I.S., 2012. Ediacaran to Lower Ordovician age for rocks ascribed to the Schist-Graywacke Complex (Iberian Massif, Spain): evidence from detrital zircon SHRIMP U-Pb geochronology. Gondwana Research, 22, 928–942.

Van Achterbergh, E., Ryan, C.G., Jackson, S.E., Griffin, W.L., 2001. Data reduction software for LA-ICP-MS: appendix. In: Sylvester, P.J. (ed.). Laser Ablation-ICP-mass spectrometry in the Earth Sciences: principles and applications. Mineralogical

Association of Canada, Short Courses Series, 29, 239–243.

Vermeesch, P., 2018. IsoplotR: A free and open toolbox for geochronology. Geoscience Frontiers, 9, 1479–1493.

Wallet, E., Padel, M., Devaere, L., Clausen, S., Álvaro, J.J., Laumonier, B., 2022. Cambrian Age 3 small shelly fossils from the Terrades inlier, southern Pyrenees, Spain: biostratigraphic and paleobiogeographic implications. Journal of Paleontology, 96, 552–582.