International Journal of Earth Sciences

, Volume 108, Issue 6, pp 2037–2046 | Cite as

Short-duration regional metamorphic event recorded in a Variscan subduction channel (Malpica–Tui eclogites, NW Iberia)

  • A. Beranoaguirre
  • P. Puelles
  • B. ÁbalosEmail author
  • J. I. Gil Ibarguchi
  • S. García de Madinabeitia
Original Paper


An isotopic resetting event is disclosed at ca. 350 Ma, based on Rb–Sr isotopic analyses (whole rock, garnet, clinopyroxene and phengite fractions) of eclogites with coronitic garnet and planolinear eclogites from the Malpica–Tui Allochthonous Complex (NW Iberia). The eclogites were buried, deformed/recrystallized and subsequently exhumed in a Late Devonian subduction channel. Lu–Hf and Sm–Nd isotopes date a ca. 375-Ma metamorphic peak of the subduction–exhumation cycle that occurred under ~ 2.6 GPa and 610–640 °C and was overprinted by the 350-Ma event, which occurred still under high-pressure conditions. The latter resetting is interpreted as a very short-duration regional metamorphic phenomenon recorded by high-pressure rocks in the west European Variscan belt at time scales shorter than those characteristic of orogenic lithosphere in subduction/collision cycles.


Eclogite Petrochronology Variscan Malpica–Tui NW Iberia 



We thank the effort towards our manuscript of reviewers Ingo Braun and, in particular, A. López-Carmona, whose comments helped to improve its quality. Financial support was provided by the Spanish Ministerio de Economía y Competitividad (MINECO) and the Fondo Europeo de Desarrollo Regional (project CGL2015-63530-P), and by the Universidad del País Vasco UPV/EHU (Grupo Consolidado project GIU15/05).


  1. Ábalos B, Puelles P, Gil Ibarguchi JI (2003) Structural assemblage of high-pressure mantle and crustal rocks in a subduction channel (Cabo Ortegal, NW Spain). Tectonics 22(1006):1.1–1.21. Google Scholar
  2. Abati J, Dunning GR (2002) Edad U-Pb en monacitas y rutilos de los paragneises de la Unidad de Agualada (Complejo de Órdenes, NW del Macizo Ibérico). Geogaceta 32:95–98Google Scholar
  3. Abati J, Gerdes A, Fernández-Suárez J, Arenas R, Whitehouse MJ, Díez Fernández R (2010) Magmatism and early-Variscan continental subduction in the northern Gondwana margin recorded in zircons from the basal units of Galicia, NW Spain. Geol Soc Am Bull 122:219–235. CrossRefGoogle Scholar
  4. Arenas R, Gil Ibarguchi I, González Lodeiro F, Klein E, Martínez Catalán JR, Ortega Gironés E, de Pablo Maciá JG, Peinado M (1986) Tectonostratigraphic units in the complexes with mafic and related rocks of the NW of the Iberian Massif. Hercynica 2:87–110Google Scholar
  5. Austrheim H (2013) Fluid and deformation induced metamorphic processes around Moho beneath continent collision zones: examples from the exposed root zone of the Caledonian mountain belt, W-Norway. Tectonophysics 609:620–635. CrossRefGoogle Scholar
  6. Ballèvre M, Martínez-Catalán JR, López-Carmona A, Pitra P, Abati J, Díez-Fernández R, Ducassou C, Arenas R, Bosse V, Castiñeiras P, Fernández-Suárez J, Gómez-Barreiro J, Paquette J-L, Peucat JJ, Poujol M, Ruffet G, Sánchez-Martínez S (2014) Correlation of the nappe stack in the Ibero-Armorican arc across the Bay of Biscay: a joint French-Spanish project. In: Schulmann K, Martínez-Catalán JR, Lardeaux JM, Janousek V, Oggiano G (eds) Variscan orogeny: extent, timescale and the formation of the European Crust, vol 405. Geological Society Special Publication, London, pp 77–113. Google Scholar
  7. Beaumont C, Ellis S, Pfiffner A (1999) Dynamics of sediment subduction-accretion at convergent margins: short-term modes, long-term deformation, and tectonic implications. J Geophys Res 104:17573–17601. CrossRefGoogle Scholar
  8. Beranoaguirre A, Pin C, Sanchez-Lorda ME, Garcia de Madinabeitia S, Gil Ibarguchi JI (2019) An evaluation of Rb-Sr isotope dilution analyses with a 86Sr-enriched tracer and Multiple Collection-ICP-MS. Int J Mass Spectrom 435:234–240. CrossRefGoogle Scholar
  9. Cloos M, Shreve RL (1988a) Subduction channel mode of prism accretion, melange formation, sediment subduction, and subduction erosion at convergent plate margins, 1, Background and description. Pure Appl Geophys 128:455–500. CrossRefGoogle Scholar
  10. Cloos M, Shreve RL (1988b) Subduction channel mode of prism accretion, melange formation, sediment subduction, and subduction erosion at convergent plate margins, 2, Implications and discussion. Pure Appl Geophys 128:501–545. CrossRefGoogle Scholar
  11. Davies GR, Tommasini S (2000) Isotopic disequilibrium during rapid crustal anatexis: implications for petrogenetic studies of magmatic processes. Chem Geol 162:169–191. CrossRefGoogle Scholar
  12. Díez Fernández R, Martínez Catalán JR (2009) 3D analysis of an Ordovician igneous ensemble: a complex magmatic structure hidden in a polydeformed allochthonous Variscan unit. J Struct Geol 31:222–236. CrossRefGoogle Scholar
  13. Díez Fernández R, Martínez Catalán JR (2012) Stretching lineations in high-pressure belts: the fingerprint of subduction and subsequent events (Malpica–Tuy complex, NW Iberia). J Geol Soc Lond 169:531–543. CrossRefGoogle Scholar
  14. Díez Fernández R, Martínez Catalán JR, 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 Res 18:385–399. CrossRefGoogle Scholar
  15. Díez Fernández R, Martínez Catalán JR, Arenas R, Abati J (2011) Tectonic evolution of a continental subduction-exhumation channel: variscan structure of the basal allochthonous units of NW Spain. Tectonics 30(TC3009):1–22. Google Scholar
  16. Dodson MH (1973) Closure temperature in cooling geochronological and petrological systems. Contrib Miner Petrol 40:259–274CrossRefGoogle Scholar
  17. Eberlei T, Habler G, Wegner W, Schuster R, Körner W, Thöni M, Abart R (2015) Rb/Sr isotopic and compositional retentivity of muscovite during deformation. Lithos 227:161–178CrossRefGoogle Scholar
  18. Engi M, Berger A, Roselle GT (2001) Role of the tectonic accretion channel in collisional orogeny. Geology 29:1143–1146.;2 CrossRefGoogle Scholar
  19. Freeman SR, Inger S, Butler RWH, Cliff RA (1997) Dating deformation using Rb–Sr in white mica: greenschist facies deformation ages from the Entrelor shear zone, Italian Alps. Tectonics 16:57–76CrossRefGoogle Scholar
  20. Fuenlabrada JM, Arenas R, Díez-Fernández R, Sánchez Martínez S, Abati J, López-Carmona A (2012) Sm-Nd isotope geochemistry and tectonic setting of the metasedimentary rocks from the basal allochthonous units of NW Iberia (Variscan suture, Galicia). Lithos 148:196–208. CrossRefGoogle Scholar
  21. García Garzón J, de Pablo Maciá JG, Llamas Borrajo JF (1981) Edades absolutas obtenidas mediante el método Rb-Sr de dos cuerpos de ortogneises en Galicia occidental. Boletín Geológico y Minero 92:463–466Google Scholar
  22. Gebauer D (1990) Isotopic systems: Geochronology of eclogites. In: Carswell DA (ed) Eclogite facies rocks. Blackie, Glasgow, pp 141–159CrossRefGoogle Scholar
  23. Gerya TV, Stöckhert B (2002) Exhumation rates of high-pressure metamorphic rocks in subduction channels: the effect of rheology. Geophys Res Lett 29:102. CrossRefGoogle Scholar
  24. Gerya TV, Stöckhert B, Perchuk AL (2002) Exhumation of high-pressure metamorphic rocks in a subduction channel: a numerical simulation. Tectonics 21:1056. CrossRefGoogle Scholar
  25. Gerya TV, Perchuk LL, Burg J-P (2008) Transient hot channels: Perpetrating and regurgitating ultrahigh-pressure, high-temperature crust–mantle associations in collision belts. In: Gerya TV, Connolly JAD, Perchuk LL (eds) Rocks generated under extreme pressure and temperature conditions: mechanisms, concepts, models. Lithos 103: 236–256.
  26. Gil Ibarguchi JI (1995) Petrology of jadeite metagranite and associated orthogneisses from the Malpica–Tuy Allochthon (NW Spain). Eur J Mineral 7:403–415. CrossRefGoogle Scholar
  27. Gil Ibarguchi JL, Dallmeyer RD (1991) Hercynian blueschist metamorphism in North Portugal: tectonothermal implications. J Metamorph Geol 9:539–549. CrossRefGoogle Scholar
  28. Gil Ibarguchi JL, Ortega Gironés E (1985) Petrology, structure and geotectonic implications of glaucophane-bearing eclogites and related rocks from Malpica–Tuy Unit, Galicia, NW Spain. Chem Geol 50:145–162. CrossRefGoogle Scholar
  29. Giletti BJ (1991) Rb and Sr diffusion in alkali feldspar, with implications for cooling histories of rocks. Geochim Cosmochim Acta 55:1331–1343. CrossRefGoogle Scholar
  30. Glodny J, Grauert B, Fiala J, Vejnar Z, Krohe A (1998) Metapegmatites in the western Bohemian massif: ages of crystallization and metamorphic overprint, as constrained by U-Pb zircon, monazite, garnet, columbite and Rb–Sr muscovite data. Geol Rundsch 87:124–134CrossRefGoogle Scholar
  31. Glodny J, Bingen B, Austrheim H, Molina JF, Rusin A (2002) Precise eclogitization ages deduced from Rb/Sr mineral systematics: the Maksyutov complex, Southern Urals, Russia. Geochim Cosmochim Acta 66:1221–1235. CrossRefGoogle Scholar
  32. Glodny J, Kühn A, Austrheim H (2008) Diffusion versus recrystallization processes in Rb-Sr geochronology: isotopic relics in eclogite facies rocks, Western Gneiss Region, Norway. Geochim Cosmochim Acta 72:506–525. CrossRefGoogle Scholar
  33. Gorczyk W, Gerya TV, Connolly JAD, Yuen DA (2007) Growth and mixing dynamics of mantle wedge plumes. Geology 35:587–590. CrossRefGoogle Scholar
  34. Gutiérrez-Alonso G, Fernández-Suárez J, López-Carmona A, Gartner A (2018) Exhuming a cold case: the early granodiorites of the northwest Iberian Variscan belt-A Visean magmatic flare-up? Lithosphere 10:194–216. CrossRefGoogle Scholar
  35. Hames WE, Bowring SA (1994) An empirical study of the argon diffusion geometry in muscovite. Earth Planet Sci Lett 124:161–169. CrossRefGoogle Scholar
  36. Harrison TM, Celerier J, Aikman AB, Hermann J, Heizler MT (2009) Diffusion of Ar-40 in muscovite. Geochim Cosmochim Acta 73:1039–1051CrossRefGoogle Scholar
  37. Jenkin GRT, Rogers G, Fallick AE, Farrow CM (1995) Rb-Sr closure temperatures in bi-mineralic rocks: a mode effect and test for different diffusion models. Chem Geol 122:227–240. CrossRefGoogle Scholar
  38. Kühn A, Glodny J, Iden K, Austrheim H (2000) Retention of Precambrian Rb/Sr phlogopite ages through Caledonian eclogite facies metamorphism, Bergen Arc Complex, W-Norway. Lithos 51:305–330. CrossRefGoogle Scholar
  39. Kuijper RP, Priem HNA, Den Tex E (1982) Late Archean—early Proterozoic source ages of zircons in rocks from the Paleozoic Orogen of Western Galicia, NW Spain. Precambr Res 19:1–29. CrossRefGoogle Scholar
  40. Li B, Massone HJ (2017) Contrasting metamorphic evolution of metapelites from the Malpica–Tuy unit and the underlying so-called parautochthon at the coast of NW Spain. Lithos 286–287:92–108. CrossRefGoogle Scholar
  41. Li B, Massonne HJ (2016) Early Variscan P-T evolution of an eclogite body and adjacent orthogneiss from the northern Malpica–Tuy shear-zone in NW Spain. Eur J Mineral 28:1131–1154. CrossRefGoogle Scholar
  42. Llana-Fúnez S, Marcos A (2001) The Malpica–Lamego line: a major crustal-scale shear zone in the Variscan belt of Iberia. J Struct Geol 23:1015–1030. CrossRefGoogle Scholar
  43. Llana-Fúnez S, Marcos A (2002) Structural record during exhumation and emplacement of high-pressure—low- to intermediate-temperature rocks in the Malpica–Tui unit (Variscan Belt of Iberia). In: Martínez Catalán JR, Jr. Hatcher RD, Arenas R, Díaz García F (eds) Variscan-Appalachian dynamics: the building of the Late Paleozoic basement, vol 364. Geological Society of America, Special Paper, Boulder, pp 125–142. CrossRefGoogle Scholar
  44. López-Carmona A, Abati J, Reche J (2010) Petrologic modelling of chloritoid-glaucophane schists from the NW Iberian Massif. In: Nance RD (ed) The Rheic Ocean: Palaeozoic evolution from Gondwana and Laurussia to Pangaea. Gondwana Res 17: 377–391.
  45. López-Carmona A, Pitra P, Abati J (2013) Blueschist-facies metapelites from the Malpica–Tui Unit (NW Iberian Massif): phase equilibria modelling and H2O and Fe2O3 influence in high-pressure assemblages. J Metamorph Geol 31:263–280. CrossRefGoogle Scholar
  46. López-Carmona A, Abati J, Pitra P, Lee JKW (2014) Retrogressed lawsonite blueschists from the NW Iberian Massif: p-T constraints from numerical modelling and 40Ar/39Ar geochronology. Contrib Miner Pet 167:1–20. CrossRefGoogle Scholar
  47. Martínez Catalán JR, Arenas R, Díaz-García F, Abati J (1997) Variscan accretionary complex of northwest Iberia: terrane correlation and succession of tectonothermal events. Geology 25:1103–1106.;2 CrossRefGoogle Scholar
  48. Meda M, Marotta AM, Spalla MI (2010) The role of mantle hydration in continental crust recycling in the wedge region. In: Spalla MI, Marotta AM, Grosso G (eds) Advances in interpretation of geological processes—refinement of multi-scale data and integration in numerical modelling, vol 332. Geological Society, Special Publications, London, pp 149–172. Google Scholar
  49. Montero P, Bea F, Corretgé LG, Floor P, Whitehouse MJ (2009) U-Pb ion microprobe dating and Sr and Nd isotope geology of the Galiñeiro Igneous Complex: a model for the peraluminous/peralkaline duality of the Cambro-Ordovician magmatism of Iberia. Lithos 107:227–238. CrossRefGoogle Scholar
  50. Ortega Gironés E (1980) Aportaciones a la estructura geológica en los alrededores de Malpica, extremo septentrional de la Fosa Blastomilonítica, La Coruña. Cuadernos del Laboratorio Geológico de Laxe 1:177–186Google Scholar
  51. Paquette JL, Ballèvre M, Peucat JJ, Cornen G (2017) From opening to subduction of an oceanic domain constrained by LA-ICP-MS U-Pb zircon dating (Variscan belt, Southern Armorican Massif, France). Lithos 294:418–437. CrossRefGoogle Scholar
  52. Pin C, Ortega LA, Gil Ibarguchi JI (1992) Mantle-derived, early Paleozoic A-type metagranitoids from the NW Iberian massif: Nd isotope and trace-element constraints. Bulletin de la Societé Géologique de France 163:483–494Google Scholar
  53. Priem HNA, Boelrijk NAIM, Verschure RH, Hebeda EH, Floor P (1966) Isotopic evidence for Upper Cambrian or Lower Ordovician granite emplacement in the Vigo area, North-Western Spain. Geol Mijnbouw 45:36–40Google Scholar
  54. Puelles P, Beranoaguirre A, Ábalos B, Gil Ibarguchi JI, García de Madinabeitia S, Rodríguez J, Fernández-Armas S (2017) Eclogite inclusions from subducted metaigneous continental crust (Malpica–Tui Allochthonous Complex, NW Spain): petrofabric, geochronology and calculated seismic properties. Tectonics 36:1376–1406. CrossRefGoogle Scholar
  55. Puelles P, Ábalos B, Gil Ibarguchi JI, Rodríguez J, Fernández-Armas S (2018) Scales of deformation partitioning during exhumation in a continental subduction channel: a petrofabric study of eclogites and gneisses from NW Spain (Malpica–Tui Allochthonous Complex). J Metamorph Geol 36:225–254. CrossRefGoogle Scholar
  56. Ries A, Shackleton RM (1971) Catazonal complexes of north-western Spain and north Portugal; remnants of a hercynian thrust plate. Nat Phys Sci 234:65–69. CrossRefGoogle Scholar
  57. Roda M, Marotta AM, Spalla MI (2010) Numerical simulations of an ocean-continent convergent system: Influence of subduction geometry and mantle wedge hydration on crustal recycling. Geochem Geophys Geosyst 11:Q05008. CrossRefGoogle Scholar
  58. Roda M, Spalla MI, Marotta AM (2012) Integration of natural data within a numerical model of ablative subduction: a possible interpretation for the Alpine dynamics of the Austroalpine crust. J Metamorph Geol 30:973–996. CrossRefGoogle Scholar
  59. Rodríguez J, Cosca MA, Gil Ibarguchi JI, Dallmeyer RD (2003) Strain partitioning and preservation of 40Ar/39Ar ages during Variscan exhumation of a subducted crust (Malpica–Tui complex, NW Spain). Lithos 70:111–139. CrossRefGoogle Scholar
  60. Santos Zalduegui JF, Schärer U, Gil Ibarguchi JI (1995) Isotope constraints on the age and origin of magmatism and metamorphism in the Malpica–Tuy Allochthon. Chem Geol 121:91–103. CrossRefGoogle Scholar
  61. Scholl DWR, von Huene R, Vallier TL, Howell DG (1980) Sedimentary masses and concepts about tectonic processes at underthrust ocean margins. Geology 8:564–568.;2 CrossRefGoogle Scholar
  62. Shreve RL, Cloos M (1986) Dynamics of sediment subduction, melange formation, and prism accretion. J Geophys Res 91:10229–10245. CrossRefGoogle Scholar
  63. Steiger RH, Jager E (1977) Subcommission on geochronology: convention on the use of decay constants in geo- and cosmochronology. Earth Planet Sci Lett 36:359–362. CrossRefGoogle Scholar
  64. Stockhert B, Gerya T (2005) Pre-collisional high-pressure metamorphism and nappe tectonics at active continental margins: a numerical simulation. Terra Nova 17:102–110. CrossRefGoogle Scholar
  65. Van Calsteren PWC, Boelrijk NAIM, Hebeda EH, Priem HNA, Den Tex E, Verdurmen EAT, Verschure RH (1979) Isotopic dating of older elements (including the Cabo Ortegal mafic-ultramafic complex) in the hercynian orogen of NW Spain: manifestations of a presumed early Palaeozoic mantle-plume. Chem Geol 24:35–56. CrossRefGoogle Scholar
  66. Viete DR, Lister GS (2017) On the significance of short-duration regional metamorphism. J Geol Soc 174:377–392. CrossRefGoogle Scholar
  67. Villa IM (1998) Isotopic closure. Terra Nova 10:42–47. CrossRefGoogle Scholar
  68. Villa IM (2010) Disequilibrium textures vs equilibrium modeling: geochronology at the crossroads. In: Spalla MI, Marotta AM, Grosso G (eds) Advances in interpretation of geological processes, vol 332. Geological Society, Special Publications, London, pp 1–15Google Scholar
  69. Villa IM, De Bièvre P, Holden NE, Renne PR (2015) IUPAC-IUGS recommendation on the half life of 87Rb. Geochim Cosmochim Acta 164:382–385. CrossRefGoogle Scholar
  70. von Blanckenburg FV, Villa IM, Baur H, Morteani G, Steiger RH (1989) Time calibration of a PT-path from the western Tauern Window, Eastern Alps: the problem of closure temperatures. Contrib Miner Pet 101:1–11. CrossRefGoogle Scholar
  71. Waight T, Baker J, Peate D (2002) Sr isotope ratio measurements by double-focusing MC-ICPMS: techniques, observations and pitfalls. Int J Mass Spectrom 221:229–244. CrossRefGoogle Scholar
  72. Warren CJ, Beaumont C, Jamieson RA (2008) Modelling tectonic styles and ultra-high pressure (UHP) rock exhumation during the transition from oceanic subduction to continental collision. Earth Planet Sci Lett 267:129–145. CrossRefGoogle Scholar
  73. Whitney DL, Evans BW (2010) Abbreviations for names of rock-forming minerals. Am Miner 95:185–187. CrossRefGoogle Scholar
  74. Yamato P, Agard P, Burov E, Le Pourthiet L, Jolivet L, Tiberi C (2007) Burial and exhumation in a subduction wedge: mutual constraints from thermomechanical modeling and natural P-T-t data (Schistes Lustres, western Alps). J Geophys Res Solid Earth 112:B07410. CrossRefGoogle Scholar
  75. Yang L, Peter C, Panne U, Sturgeon RE (2008) Use of Zr for mass bias correction in strontium isotope ratio determinations using MC-ICP-MS. J Anal At Spectrom 23:1269–1274. CrossRefGoogle Scholar

Copyright information

© Geologische Vereinigung e.V. (GV) 2019

Authors and Affiliations

  1. 1.Área de Laboratorios, Instituto Geológico y Minero de EspañaMadridSpain
  2. 2.Departamento de GeodinámicaUniversidad del País Vasco, UPV/EHUBilbaoSpain
  3. 3.Departamento de Mineralogía y PetrologíaUniversidad del País Vasco, UPV/EHUBilbaoSpain
  4. 4.Institut für GeowissenschaftenGoethe-UniversitätFrankfurt am MainGermany

Personalised recommendations