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The Sardic Phase: field evidence of Ordovician tectonics in SE Sardinia, Italy

Published online by Cambridge University Press:  14 September 2017

FABRIZIO COCCO  and
ANTONIO FUNEDDA
FABRIZIO COCCO
Affiliation:
Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, via Trentino 51, 09127, Cagliari, Italy
ANTONIO FUNEDDA*
Affiliation:
Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, via Trentino 51, 09127, Cagliari, Italy
*
*Author for correspondence: afunedda@unica.it
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Abstract

Detailed geological mapping, field observations and structural analyses demonstrate that Early Ordovician (‘Sardic’) deformation occurred in the early Palaeozoic successions that are now incorporated in the Variscan Nappe zone of SE Sardinia. This deformation is represented by folds that formed at a shallow depth, lack a significant syn-folding axial planar foliation, and do not affect the overlying Late Ordovician – Devonian sedimentary sequence. These deformation features can be related to the development of the Sardic Unconformity and to calc-alkaline volcanism in several now-scattered terranes of Ordovician northern Gondwana. This reflects a convergent geodynamic setting that in the study sector appears to have failed to reach a continental collisional end-stage. Associating the structural data from this study with those of several published research studies, a preliminary evaluation about which tectonic setting could better fit is proposed. These conditions affected the eastern side of the northern Gondwana margin more or less contemporaneously with the opening of the Rhéic Ocean and the closure of the Qaidam Ocean, before the amalgamation of the Hunia terranes.

Keywords

Gondwana tectonicsstructural analysisQaidam OceanRhéic OceanEarly Ordovician
Type
Original Articles
Information
Geological Magazine , Volume 156 , Issue 1 , January 2019 , pp. 25 - 38
Copyright
Copyright © Cambridge University Press 2017 

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References

Alexandre, P. 2007. U-Pb zircon SIMS ages from the French Massif Central and implication for the pre-Variscan tectonic evolution in Western Europe. Comptes Rendus Geosciences 339, 613–21.Google Scholar
Alvaro, J., Colmenar, J., Monceret, E., Pouclet, A. & Vizcaino, D. 2016. Late Ordovician (post-Sardic) rifting branches in the North Gondwanan Montagne Noire and Mouthoumet massifs of southern France. Tectonophysics 681, 111–23.Google Scholar
Arthaud, F. 1963. Un exemple de tectoniques superposées dans le Paleozoique de l'Iglesiente (Sardaigne). Comptes Rendus de la Société Géologique de France 9, 303–4.Google Scholar
Barca, S. 1991. Phénomènes de resédimentation et flysch hercynien à faciès Culm dans le “synclinal du Sarabus” (SE de la Sardaigne, Italie). Comptes Rendus de l'Académie des Sciences de Paris 313 (2), 1051–7.Google Scholar
Barca, S., Del Rio, M. & Pittau Demelia, P. 1988. New geological and stratigraphical data and discovery of Lower Ordovician acritarchs in the San Vito Sandstone of the Genn'Argiolas Unit (Sarrabus, Southeastern Sardinia). Rivista Italiana di Paleontologia e Stratigrafia 94 (3), 339–60.Google Scholar
Barca, S. & Jäger, H. 1989. New geological and biostratigraphical data on the Silurian in SE Sardinia. Close affinity with Thuringia. Bollettino della Società Geologica Italiana 108 (4), 565–80.Google Scholar
Calvino, F. 1959. Lineamenti strutturali del Sarrabus-Gerrei (Sardegna sud-orientale). Bollettino del Servizio Geologico d'Italia 81 (4–5), 489–556.Google Scholar
Carmignani, L., Carosi, R., Di Pisa, A., Gattiglio, M., Musumeci, G., Oggiano, G. & Pertusati, P. C. 1994. The Hercynian chain in Sardinia (Italy). Geodinamica Acta 7, 31–47.Google Scholar
Carmignani, L., Conti, P., Barca, S., Cerbai, N., Eltrudis, A., Funedda, A., Oggiano, G., Patta, E. D., Ulzega, A., Orrù, P. & Pintus, C. 2001 a. Foglio 549-Muravera. Note illustrative. Roma: Servizio Geologico d'Italia.Google Scholar
Carmignani, L., Oggiano, G., Barca, S., Conti, P., Salvadori, I., Eltrudis, A., Funedda, A. & Pasci, S. 2001 b. Geologia della Sardegna. Note illustrative della Carta Geologica in scala 1:200.000. Roma: Servizio Geologico d'Italia.Google Scholar
Casas, J. M. 2010. Ordovician deformations in the Pyrenees: new insights into the significance of pre-Variscan (‘sardic’) tectonics. Geological Magazine 147 (5), 674–89.Google Scholar
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 (2–3), 317–24.Google Scholar
Casas, J. M. & Palacios, T. 2012. First biostratigraphical constraints on the pre-Upper Ordovician sequences of the Pyrenees based on organic-walled microfossils. Comptes Rendus Geoscience 344, 50–6.Google Scholar
Casas, J. M., Queralt, P., Mncos, J. & Gratacòs, O. 2012. Distribution of linear mesostructures in oblique folded surfaces: Unravelling superposed Ordovician and Variscan folds in the Pyrenees. Journal of Structural Geology 44, 141–50.Google Scholar
Castiñeiras, P., Navidad, M., Liesa, M., Carreras, J. & Casas, J. M. 2008. U-Pb zircon ages (SHRIMP) for Cadomian and Early Ordovician magmatism in the Eastern Pyrenees: new insights into the pre-Variscan evolution of the northern Gondwana margin. Tectonophysics 8, doi:10.1016/j.tecto.2008.04.005.Google Scholar
Cavet, P. 1957. Le Paléozoïque de la zone axiale des Pyrénées orientales françaises entre le Roussillon et l'Andorre. Bulletin du Service de la Carte Géologique de la France 55, 303–518.Google Scholar
Cocco, F. & Funedda, A. 2011. New data on the pre-Middle Ordovician deformation in SE Sardinia: a preliminary note. Rendiconti online della Società Geologica Italiana 15, 34–36.Google Scholar
Cocco, F. & Funedda, A. 2012. The Variscan basement of the Riu Ollastu area (Sarrabus, SE Sardinia, Italy). Geology of France and Surrounding Areas 1, 89–91.Google Scholar
Cocozza, T. 1967. Il Permo-Carbonifero del Bacino di San Giorgio (Iglesiente, Sardegna Sud Occidentale). Memorie della Società Geologica Italiana 6, 607–42.Google Scholar
Cocozza, T. 1979. The Cambrian of Sardinia. Memorie della Società Geologica Italiana 20, 163–87.Google Scholar
Collins, W. J. 2002. Hot orogens, tectonic switching, and creation of continental crust. Geology 30, 535–8.Google Scholar
Conti, P., Carmignani, L. & Funedda, A. 2001. Change of nappe transport direction during the Variscan collisional evolution of central-southern Sardinia (Italy). Tectonophysics 332 (1–2), 255–73.Google Scholar
Conti, P., Carmignani, L., Oggiano, G., Funedda, A. & Eltrudis, A. 1999. From thickening to extension in the Variscan belt: kinematic evidence from Sardinia (Italy). Terra Nova 11 (2–3), 93–9.Google Scholar
Conti, P. & Patta, E. D. 1998. Large scale W-directed tectonics in southeastern Sardinia. Geodinamica Acta 11 (5), 217–31.Google Scholar
Corradini, C., Barca, S. & Spalletta, C. 2003. Late Devonian-Early Carboniferous conodonts from the “Clymeniae Limestones” of SE Sardinia (Italy). Courier Forschungsinstitut Senckenberg 245, 227–53.Google Scholar
Corradini, C. & Ferretti, A. 2009. The Silurian of the external Nappes (southeastern Sardinia). Rendiconti della Società Paleontologica Italiana 48 (1), 43–9.Google Scholar
Crook, K. A. W. 1980. Fore-arc evolution and continental growth: a general model. Journal of Structural Geology 2 (3), 289–303.Google Scholar
De Franco, R., Govers, R. & Wortel, R. 2007. Numerical comparison of different convergent plate contacts: subduction channel and subduction fault. Geophysical Journal International 171 (1), 435–50.Google Scholar
Del Greco, K., Johnston, S. T. & Shaw, J. 2016. Tectonic setting of the North Gondwana margin during the Early Ordovician: a comparison of the Ollo de Sapo and Famatina magmatic events. Tectonophysics 681, 73–84.Google Scholar
Den Brok, S. W. J. 1989. Evidence for pre-Variscan deformation in the Lys Caillaouas area, Central Pyrenees, France. Geologie en Mijnbouw 68, 377–80.Google Scholar
Diaz Garcia, F. 2006. Geometry and regional significance of Neoproterozoic (Cadomian) structures of the Narcea antiform, NW Spain. Journal of Geological Society (London) 163, 499–508.Google Scholar
Domeier, M. 2016. A plate tectonic scenario for the Iapetus and Rheic oceans. Gondwana Research 36, 275–95.Google Scholar
Foster, D. A. & Grey, D. R. 2000. Evolution and structure of the Lachlan fold-belt (Orogen) of Eastern Australia. Annual Review of Earth and Planetary Sciences 28, 47–80.Google Scholar
Gaggero, L., Oggiano, G., Funedda, A. & Buzzi, L. 2012. Rifting and arc-related early Paleozoic volcanism along the North Gondwana margin: geochemical and geological evidence from Sardinia (Italy). Journal of Geology 120 (3), 273–92.Google Scholar
Galassi, R. & Gandin, A. 1992. New structural data and their bearing on the Cambrian stratigraphy of the Iglesiente region (SW Sardinia, Italy). Comptes Rendus de l'Académie des Sciences de Paris 314, 93–100.Google Scholar
Glen, R. A. 2005. The Tasmanides of eastern Australia. In Terrane Processes at the Margins of Gondwana (eds Vaughan, A. P. M., Leat, P. T. & Pankhurst, R. J.), pp. 93–100. Geological Society of London, Special Publication no. 246.Google Scholar
Gnoli, M. & Pillola, G. L. 2002. The oldest nautiloid cephalopod of Sardinia: Cameroceras cf. vertebrale (Eichwald, 1860) from the Arenig (Early Ordovician) of Tacconis (South East Sardinia) and remarks on associated biota. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 2002 (1), 19–26.Google Scholar
Hamman, W. & Leone, F. 1997. Trilobites of the Post-Sardic (Upper Ordovician) Sequence of Southern Sardinia. Part 1. Wurzburg: Institute fur Geologie und Palaontologie.Google Scholar
Hartevelt, J. J. A. 1970. Geology of the Upper Segre and Valira valleys, central Pyrenees, Andorra/Spain. Leidse Geologische Mededelingen 45, 167–236.Google Scholar
Lancelot, J., Moussavou, M. & Delor, C. 1998. Geochronologie U/Pb des temoins de l'evolution ante-varisque du massif des Maures. In BRGM-SGF Special Meeting: Géologie du Massif des Maures, Le Plan de Tour, 20 May, p. 22.Google Scholar
Laske, R., Bechstadt, T. & Boni, M. 1994. The post-Sardic Ordovician series. In Sedimentological, Stratigraphical and Ore Deposits Field Guide of the Autochtonous Cambro-Ordovician of Southwestern Sardinia (eds Bechstadt, T. & Boni, M.), pp. 115–46. Servizio Geologico d'Italia, Roma, Memorie Descrittive della Carta Geologica d'Italia.Google Scholar
Laumonier, B. 2008. Les Pyrénées pré-hercyniennes et hercyniennes. In Pyrénées D'hier et D'aujourd'hui (eds Canérot, J., Colin, J.-P., Platel, J.-P. & Bilotte, M.). Colloque de Pau, France, 20–21 September 2008, Atlantica, pp. 23–35.Google Scholar
Leone, F., Hamman, W., Laske, R., Serpagli, E. & Villas, E. 1991. Lithostratigraphic units and biostratigraphy of the post-sardic Ordovician sequence in south-west Sardinia. Bollettino della Società Paleontologica Italiana 30 (2), 201–35.Google Scholar
Li, Z., Pei, X., Li, R., Pei, L., Liu, C., Chen, Y., Zhang, Y., Wang, M. & Xu, T. 2016. Early Ordovician island-arc-type Manite granodiorite pluton from the Buqingshan Tectonic Mélange Belt in the southern margin of the East Kunlun Orogen: constraints on subduction of the Proto-Tethyan Ocean. Geological Journal 52, 510–28.Google Scholar
Loi, A., Barca, S., Chauvel, J. J., Dabard, M. P. & Leone, F. 1992. Analyse de la sédimentation post-phase sarde: les dépôts initiaux à placers du SE de la Sardaigne. Comptes Rendus de la Société Géologique de France, serie II 315 (2), 1357–64.Google Scholar
Loi, A. & Dabard, M. P. 1997. Zircon typology and geochemistry in the palaeogeographic reconstruction of the Late Ordovician of Sardinia (Italy). Sedimentary Geology 112, 263–79.Google Scholar
Malatesta, C., Gerya, T., Crispini, L., Federico, L. & Capponi, G. C. T. C. 2016. Interplate deformation at early-stage oblique subduction: 3-D thermomechanical numerical modeling. Tectonics 35 (7), 1610–25.Google Scholar
Martini, I. P., Tongiorgi, M., Oggiano, G. & Cocozza, T. 1991. Ordovician alluvial fan to marine shelf transition in SW Sardinia, Western Mediterranean Sea: tectonically (“Sardic phase”) influenced clastic sedimentation. Sedimentary Geology 72, 97–115.Google Scholar
Nance, R. D., Gutierrez-Alonso, G., Keppie, J. D., Linnemann, U., Murphy, J. B., Quesada, C., Strachan, R. A. & Woodcock, N. H. 2010. Evolution of the Rheic Ocean. Gondwana Research 17, 194–222.Google Scholar
Oggiano, G., Gaggero, L., Funedda, A., Buzzi, L. & Tiepolo, M. 2010. Multiple early Paleozoic volcanic events at the northern Gondwana margin: U-Pb age evidence from the Southern Variscan branch (Sardinia, Italy). Gondwana Research 17 (1), 44–58.Google Scholar
Okay, A., Satir, M. & Shang, C. K. 2008. Ordovician metagranitoid from the Anatolide-Tauride Block, northwest Turkey: geodynamic implications. Terra Nova 20 (4), 280–8.Google Scholar
Pasci, S., Pertusati, P. C., Salvadori, I. & Murtas, M. 2008. I rilevamenti CARG del foglio geologico 555 “Iglesias” e le nuove implicazioni strutturali sulla tettonica della “Fase Sarda”. Rendiconti online della Società Geologica Italiana 3, 614–5.Google Scholar
Pavanetto, P., Funedda, A., Northrup, C. J., Schmitz, M., Crowley, J. & Loi, A. 2012. Structure and U–Pb zircon geochronology in the Variscan foreland of SW Sardinia, Italy. Geological Journal 47 (4), 426–45.Google Scholar
Pillola, G. L., Leone, F. & Loi, A. 1998. The Cambrian and Early Ordovician of SW Sardinia. Giornale di Geologia 60, 25–38.Google Scholar
Pillola, G. L., Piras, S. & Serpagli, E. 2008. Upper-Tremadoc-Lower Arenig? Anisograptid-Dichograptid fauna from the Cabitza Formation (Lower Ordovician, SW Sardinia, Italy). Revue de Micropaléontologie 51, 167–81.Google Scholar
Pistis, M., Loi, A. & Dabard, M. P. 2016. Influence of relative sea-level variations on the genesis of paleoplacers, the examples of Sarrabus (Sardinia, Italy) and the Armorican Massif (Western France). Comptes Rendus Geosciences 348 (2), 150–7.Google Scholar
Pittau, P., Del Rio, M. & Funedda, A. 2008. Relationships between plant communities characterization and basin formation in the Carboniferous-Permian of Sardinia. Bollettino della Società Geologica Italiana 127 (3), 637–53.Google Scholar
Romão, J. M. C., Coke, C., Dias, R. & Ribeiro, A. 2005. Transient inversion during the opening stage of the Wilson cycle “Sardic Phase” in the Iberian Variscides: stratigraphic and tectonic record. Geodinamica Acta 18 (2), 115–29.Google Scholar
Rossi, P., Oggiano, G. & Cocherie, A. 2009. A restored section of the “southern Variscan realm” across the Corsica-Sardinia microcontinent. Comptes Rendus Geosciences 341 (2–3), 224–38.Google Scholar
Shackleton, R. M. 1957. Downward-facing structures of the Highland Border. Quarterly Journal of the Geological Society of London 113, 361–92.Google Scholar
Solà, A. R., Pereira, M. F., Williams, I. S., Ribeiro, M. L., Neiva, A. M. R., Montero, P., Bea, F. & Zinger, T. 2008. New insights from U-Pb zircon dating of Early Ordovician magmatism on the northern Gondwana margin: The Urra Formation (SW Iberian Massif, Portugal). Tectonophysics 461, 114–29.Google Scholar
Stampfli, G., Hochard, C., Vérard, C., Wilhem, C. & von Raumer, J. 2013. The formation of Pangea. Tectonophysics 593, 1–19.Google Scholar
Stille, H. 1939. Bemerkungen betreffend die “sardische Faltung” und den Ausdruck “ophiolitisch”. Zeitschrift der Deutschen Geologischen Gesellschaft 91, 771–3.Google Scholar
Taira, A. 2001. Tectonic evolution of the Japanese Island Arc System. Annual Review of Earth and Planetary Sciences 29, 109–34.Google Scholar
Teichmüller, R. 1931. Zur Geologie des Thyrrhenisgebietes. Teil 1: Alte und junge Krustenbewegungen im südlichen Sardinien. Abhandlungen von der Gesellschaft der Wissenschaften zu Göttingen, Mathematisch-Physikalische Klasse 3 (3), 857–950.Google Scholar
Trombetta, A., Cirrincione, R., Corfu, F., Mazzoleni, P. & Pezzino, A. 2004. Mid-Ordovician U-Pb ages of porphyroids in the Peloritan Mountains (NE Sicily): paleogeographical implications for the evolution of the Alboran microplate. Journal of Geological Society (London) 161, 256–76.Google Scholar
Twiss, R. J. 1988. Description and classification of folds in single surfaces. Journal of Structural Geology 10 (6), 607–23.Google Scholar
von Raumer, J., Bussy, F., Schaltegger, U., Schulz, B. & Stampfli, G. 2013. Pre-Mesozoic Alpine basements: their place in the European Paleozoic framework. Geological Society of America Bulletin 125 (1–2), 89–108.Google Scholar
von Raumer, J. & Stampfli, G. 2008. The birth of the Rheic Ocean: Early Palaezoic subsidence patterns and subsequent tectonic plate scenarios. Tectonophysics 461, 9–20.Google Scholar
von Raumer, J. F., Stampfli, G. M., Arenas, R. & Sànchez Martìnez, S. 2015. Ediacaran to Cambrian oceanic rocks of the Gondwana margin and their tectonic interpretation. International Journal of Earth Sciences 104 (5), 1107–21.Google Scholar
Zurbriggen, R. 2015. Ordovician orogeny in the Alps: a reappraisal. International Journal of Earth Science 104 (2), 335–50.Google Scholar
Zurbriggen, R. 2017. The Cenerian orogeny (early Paleozoic) from the perspective of the Alpine region. International Journal of Earth Sciences 106 (2), 517–29.Google Scholar