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STRATI 2013 pp 741-745 | Cite as

The Significance of Changes of Source Areas During Carboniferous Turbiditic Deposition (Southwestern Iberia)

  • M. F. PereiraEmail author
  • M. Chichorro
  • G. Gutierrez-Alonso
  • F. Vilallonga
  • K. Drost
  • C. Ribeiro
  • J. B. Silva
  • L. Albardeiro
  • M. Hofmann
  • U. Linnemann
Conference paper
Part of the Springer Geology book series (SPRINGERGEOL)

Abstract

U–Pb dating of detrital zircons from the Carboniferous turbidites of southwestern Iberia (the Cabrela, Mértola, Mira, and Brejeira formations) shows that synorogenic sedimentation during the Carboniferous was marked by significant variations in the source areas, involving the denudation of different crustal blocks and a break in synorogenic volcanism. The Visean is characterized by the accumulation of immature turbidites (the Cabrela and Mértola formations and the base of the Mira Formation). These turbidites were probably formed in relation to sources (magmatic arcs) of Mid–Late Devonian age poorly influenced by sedimentary recycling, as indicated by the near-absence of pre-Devonian zircons, ages that are typical of the Gondwana basement. The presence of Carboniferous grains in Visean turbidites indicates that volcanism was active at this time. Later, Serpukhovian to Moscovian turbiditic sedimentation (the Mira and Brejeira formations) included sedimentary detritus derived from mature felsic source rocks situated far from active magmatism. The abundance of Proterozoic and Palaeozoic zircons reveals strong recycling of the pre-Carboniferous basement. A peri-Gondwanan provenance is indicated by zircon populations with Neoproterozoic (the Cadomian–Avalonian and Pan-African zircon-forming events), Palaeoproterozoic, and Archean (the West African Craton zircon-forming events) ages. The presence of Late Ordovician and Silurian detrital zircons in the Brejeira turbidites, which do not correspond to the Gondwana basement of southwestern Iberia, indicates an external source (Laurussia?).

Keywords

U–Pb zircon geochronology South Portuguese Zone Ossa–Morena Zone Variscan orogeny Pangaea 

Notes

Acknowledgments

This paper is a contribution to research projects GONDWANA-PTDC/CTE-GIX/110426/2009 and GOLD- PTDC/GEO–GEO/2446/2012 (Portugal) and to IGCP projects 574 “Bending and bent orogens, and continental ribbons” and 597 “Amalgamation and breakup of Pangaea: the type example of the supercontinent cycle” (UNESCO-IUGS). It is a contribution to project PEst-OE/CTE/UI4073/2014.

References

  1. Braid, J. A., Murphy, J. B., Quesada, C., & Mortensen, J. (2011). Tectonic escape of a crustal fragment during the closure of the Rheic Ocean: U-Pb detrital zircon data from the late Palaeozoic Pulo de Lobo and South Portuguese Zones, Southern Iberia. Journal of the Geological Society of London,168, 383–392.CrossRefGoogle Scholar
  2. Díez Fernández, R., Martínez Catalán, J. R., Gerdes, A., Abati, J., Arenas, R., & Fernández-Suárez, J. (2010). U-Pb ages of detrital zircons from the Basal allochthonous units of NW Iberia: Provenance and paleoposition on the northern margin of Gondwana during the Neoproterozoic and Paleozoic. Gondwana Research,18(2–3), 385–399.CrossRefGoogle Scholar
  3. Gutierrez-Alonso, G., Fernandez-Suarez, J., Jeffries, T., Jenner, G. A., 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.CrossRefGoogle Scholar
  4. Keppie, J. D., & Krogh, T. E. (2000). 440 Ma igneous activity in the Meguma terrane, Nova Scotia, Canada: Part of the Appalachian overstep sequence? American Journal of Science,300, 528–538.CrossRefGoogle Scholar
  5. Linnemann, U., Pereira, M.F., Jeffries, T., Drost, K., & Gerdes, A. (2008). Cadomian Orogeny and the opening of the Rheic Ocean: new insights in 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.CrossRefGoogle Scholar
  6. Meinhold, G., Morton, A. C., & Avigad, D. (2012). New insights into peri-Gondwana paleogeography and the Gondwana super-fan system from detrital zircon U-Pb ages. Gondwana Research,23(2), 661–665.CrossRefGoogle Scholar
  7. Murphy, J. B., van Staal, C. R., & Collins, W. J. (2011). A comparison of the evolution of arc complexes in Paleozoic interior and peripheral orogens: Speculations on geodynamic correlations. Gondwana Research,19(3), 812–827.CrossRefGoogle Scholar
  8. Nance, R.D., Murphy, J.B., Strachan, R.A., Keppie, J.D., Gutierrez-Alonso, G., Fernandez-Suarez, J., Quesada, C., Linnemann, U., D’Lemos, R., & Pisarevsky, S.A. (2008). Neoproterozoic-early Paleozoic tectonostratigraphy and palaeogeography of the peri-Gondwanan terranes: Amazonian v. West African connections. In: Ennih, N., Liegeois, J.P. (Eds). The boundaries of the West African Craton. Geological Society of London (Spec Pub) 297, 345–383.Google Scholar
  9. Oliveira, J. T. (1990). Stratigraphy and syn-sedimentary tectonism in the South Portuguese Zone. In R. D. Dallmeyer & E. Martinez Garcia (Eds.), Pre-Mesozoic geology of Iberia (pp. 334–347).Google Scholar
  10. Pastor-Galán, D., Gutierrez-Alonso, G., Murphy, J. B., Fernandez-Suarez, J., Hofmann, M., & Linnemann, U. (2012). Provenance analysis of the Paleozoic sequences of the northern Gondwana margin in NW Iberia: Passive margin to Variscan collision and orocline development. Gondwana Research,23(3), 1089–1103.CrossRefGoogle Scholar
  11. Pereira, M. F., Ribeiro, C., Vilallonga, F., Chichorro, M., Drost, K., Silva, J. B., et al. (2013) Variability over time in the sources of South-Portuguese Zone turbidites: Evidence of denudation of different crustal blocks during the assembly of Pangaea. International Journal of Earth Science, published online http://link.springer.com/article/10.1007%2Fs00531-013-0902-8#page-1.
  12. Pereira, M. F., Chichorro, M., Johnston, S. T., Gutierrez-Alonso, G., Silva, J. B., Linnemann, U., et al. (2012a). The missing Rheic Ocean magmatic arcs: Provenance analysis of Late Paleozoic sedimentary clastic rocks of SW Iberia. Gondwana Research,22(3–4), 882–891.CrossRefGoogle Scholar
  13. Pereira, M. F., Linnemann, U., Hofmann, M., Chichorro, M., Solá, A. R., Medina, J., et al. (2012b). The provenance of Late Ediacaran and Early Ordovician siliciclastic rocks in the Southwest Central Iberian Zone: Constraints from detrital zircon data on northern Gondwana margin evolution during the late Neoproterozoic. Precambrian Research,192–195, 166–189.CrossRefGoogle Scholar
  14. Quesada, C., Robardet, M., & Gabaldon, V. (1990). Ossa–Morena Zone- Stratigraphy: Synorogenic phase (Upper Devonian–Carboniferous–Lower Permian). In R. D. Dallmeyer & E. Martinez Garcia (Eds.), Pre-Mesozoic geology of Iberia (pp. 273–279). Berlin: Springer.Google Scholar
  15. Robardet, M., & Gutierrez-Marco, J. C. (2004). The Ordovician, Silurian and Devonian sedimentary rocks of the Ossa-Morena Zone (SW Iberian Peninsula, Spain). Journal of Iberian Geology,30, 73–92.Google Scholar
  16. Sánchez-García, T., Bellido, F., Pereira, M. F., Chichorro, M., Quesada, C., Pin, C., et al. (2010). Rift related volcanism predating the birth of the Rheic Ocean (Ossa–Morena Zone, SW Iberia). Gondwana Research,17(2–4), 392–407.CrossRefGoogle Scholar
  17. van Staal, C. R., Whalen, J. B., Valverde-Vaquero, P., Zagorevski, A., & Rogers, N. (2009). Pre-Carboniferous, episodic accretion-related, orogenesis along the Laurentian margin of the northern Appalachians. Geological Society London, Special Publications, 327, 271–316.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • M. F. Pereira
    • 1
    Email author
  • M. Chichorro
    • 2
  • G. Gutierrez-Alonso
    • 3
  • F. Vilallonga
    • 1
  • K. Drost
    • 4
  • C. Ribeiro
    • 5
  • J. B. Silva
    • 6
  • L. Albardeiro
    • 1
  • M. Hofmann
    • 7
  • U. Linnemann
    • 7
  1. 1.IDL, Departamento de GeociênciasECT, Universidade de ÉvoraÉvoraPortugal
  2. 2.CICEGe, Departamento de Ciências da Terra, Faculdade de Ciências e TecnologiaUniversidade Nova de LisboaCaparicaPortugal
  3. 3.Departamiento de GeodinámicaUniversidad de SalamancaSalamancaSpain
  4. 4.Department of GeosciencesUniversity of TubingenTübingenGermany
  5. 5.CGE, Departamento de Geociências, Escola de Ciencias e TecnologiaUniversidade de ÉvoraÉvoraPortugal
  6. 6.IDL, Departamento de GeologiaFaculdade de Ciências da Universidade de LisboaLisbonPortugal
  7. 7.Senckenberg Naturhistorische Sammlungen DresdenDresdenGermany

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