Mineralogy and Petrology

, Volume 112, Issue 4, pp 535–553 | Cite as

Growth of chloritoid and garnet along a nearly isothermal burial path to 70 km depth: an example from the Bughea Metamorphic Complex, Leaota Massif, South Carpathians

  • Elena Negulescu
  • Gavril Săbău
  • Hans-Joachim Massonne
Original Paper


Chloritoid-bearing micaschist occurs in the matrix of a subduction mélange (Bughea Complex) of the Leaota Massif (South Carpathians) containing blocks of high-pressure rocks such as eclogite and metagabbronorite. Chloritoid is Mg rich and exclusively enclosed together with chlorite, epidote, paragonite, phengite, quartz, and rutile in mm-sized garnet porphyroblasts embedded in a matrix rich in white mica and chlorite. The Mg content of chloritoid inclusions systematically increases outwards from the inner core of garnet porphyroblasts. Modelling using a pressure (P) — temperature (T) pseudosection predicts the growth of chloritoid together with garnet at the expense of chlorite and other Al-rich phases, while following a nearly isothermal P-T path from 13 kbar and 540 °C to 21 kbar and 560 °C. Breakdown of chloritoid occurred along a P-T path characterised by heating and decompression to 600 °C and 15 kbar. The constrained P-T path is compatible with previously determined ones for eclogites in the Bughea Complex, namely burial in a subduction-accretion complex to depths of 70 km, detachment from the subducting slab, tectonic mixing with blocks sampled from different depths, and, thus, exhumation in a subduction channel.


Mg-rich chloritoid Garnet zoning P-T path Pseudosection Micaschist High-pressure metamorphism 



We would like to thank Thomas Theye for the invaluable help provided with the use of the EPMA. Thorough and constructive reviews by Pavel Pitra and Arne Willner, as well as helpful suggestions and directions from the Editor Shah Wali Faryad and Editor-in-Chief Lutz Nasdala are thankfully acknowledged. This contribution was financially supported by Deutscher Akademischer Austauschdienst through grant A/13/03102, and the Romanian Executive Unit for Financing Higher Education, Research, Development and Innovation through grant PN-II-ID-PCE-2011-3-0030.

Supplementary material

710_2017_552_MOESM1_ESM.pdf (890 kb)
Supplementary material 1 (PDF 889 KB)


  1. Ague JJ, Carlson WD (2013) Metamorphism as garnet sees it: The kinetics of nucleation and growth, equilibration, and diffusional relaxation. Elements 9:439–445CrossRefGoogle Scholar
  2. Balintoni I, Balica C, Ducea MN, Chen F, Hann H, Şabliovschi V (2009) Late Cambrian–Early Ordovician Gondwanan terranes in the Romanian Carpathians: A zircon U–Pb provenance study. Gondwana Res 16:119–133CrossRefGoogle Scholar
  3. Bernhardt HJ, Massonne H-J, Reinecke T, Reinhardt J, Willner A (1995) Digital element distribution maps, an aid for petrological investigations. Ber Dtsch Mineral Ges, Beih Eur J Mineral 7(1):28Google Scholar
  4. Chopin C, Schreyer W (1983) Magnesiocarpholite and magnesiochloritoid: two index minerals of pelitic blueschists and their preliminary phase relations in the model system MgO-Al2O3-SiO2-H2O. Am J Sci 283-A:72–96Google Scholar
  5. Connolly JAD (1990) Multivariable phase diagrams: an algorithm based on generalized thermodynamics. Am J Sci 290:666–718CrossRefGoogle Scholar
  6. Connolly JAD (2005) Computation of phase equilibria by linear programming: a tool for geodynamic modeling and its application to subduction zone decarbonation. Earth Planet Sc Lett 236:524–541CrossRefGoogle Scholar
  7. Connolly JAD, Petrini K (2002) An automated strategy for calculation of phase diagram sections and retrieval of rock properties as a function of physical conditions. J Metamorph Geol 20:697–708CrossRefGoogle Scholar
  8. Dale J, Powell R, White RW, Elmer FL, Holland TJB (2005) A thermodynamic model for Ca-Na clinoamphiboles in Na2O-CaO-FeO-MgO-Al2O3-SiO2-H2O-O for petrological calculations. J Metamorph Geol 23:771–791CrossRefGoogle Scholar
  9. Diener JFA, Powell R (2012) Revised activity–composition models for clinopyroxene and amphibole. J Metamorph Geol 30:131–142CrossRefGoogle Scholar
  10. Diener JFA, Powell R, White RW, Holland TJB (2007) A new thermodynamic model for clino- and orthoamphiboles in the system Na2O-CaO-FeO-MgO-Al2O3-SiO2-H2O-O. J Metamorph Geol 25:631–656CrossRefGoogle Scholar
  11. Evans TP (2004) A method for calculating effective bulk composition modification due to crystal fractionation in garnet-bearing schist: implications for isopleth thermobarometry. J Metamorph Geol 22:547–557CrossRefGoogle Scholar
  12. Faryad SW (1995) Petrology and phase relations of low-grade high-pressure metasediments from the Meliata Unit (West Carpathians, Slovakia). Eur J Mineral 7:71–87CrossRefGoogle Scholar
  13. Gabriele P, Ballèvre M, Jaillard E, Hernandez J (2003) Garnet-chloritoid-kyanite metapelites from the Raspas Complex (SW Ecuador): a key eclogite facies assemblage. Eur J Mineral 15:977–989CrossRefGoogle Scholar
  14. Gheuca I, Dinică I (1996) Excursion guide, excursion C3: The metamorphic basement of the Getic Nappe in the eastern margin of the South Carpathians (Iezer and Leaota Mountains). Anu Inst Geol Rom 69, Supplement 9Google Scholar
  15. Holland TJB, Powell R (1998) An internally consistent thermodynamic data set for phases of petrological interest. J Metamorph Geol 16:309–343CrossRefGoogle Scholar
  16. Holland T, Baker J, Powell R (1998) Mixing properties and activity-composition relationships of chlorites in the system MgO-FeO-Al2O3-SiO2-H2O. Eur J Mineral 10:395–406CrossRefGoogle Scholar
  17. Hoschek G (2013) Garnet zonation in metapelitic schists from the Eclogite Zone, Tauern Window, Austria: comparison of observed and calculated profiles. Eur J Mineral 25:615–629CrossRefGoogle Scholar
  18. Hoschek G, Konzett J, Tessadri R (2010) Phase equilibria in quartzitic garnet-kyanite-chloritoid micaschist from the Eclogite Zone, Tauern Window, Eastern Alps. Eur J Mineral 22:721–732CrossRefGoogle Scholar
  19. Konopásek J (2001) Eclogitic micaschists in the central part of the Krušné hory Mountains (Bohemian Massif). Eur J Mineral 13:87–100CrossRefGoogle Scholar
  20. Konrad-Schmolke M, O’Brien PJ, De Capitani C, Carswell DA (2008) Garnet growth at high- and ultra-high pressure conditions and the effect of element fractionation on mineral modes and composition. Lithos 103:309–332CrossRefGoogle Scholar
  21. Li B, Massonne H-J (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 28:1131–1154CrossRefGoogle Scholar
  22. Li B, Massonne H-J, Opitz J (2017) Clockwise and anticlockwise P-T paths of high-pressure rocks from the ‘La Pioza’ eclogite body of the Malpica-Tuy zone, NW Spain. J Petrol.
  23. Lopez-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 31:263–280CrossRefGoogle Scholar
  24. Manzotti P, Pitra P, Langlade J, Ballèvre M (2015) Constraining P–T conditions during thrusting of a higher pressure unit over a lower pressure one (Gran Paradiso, Western Alps). J Metamorph Geol 33:981–1002CrossRefGoogle Scholar
  25. Marmo BA, Clarke GL, Powell R (2002) Fractionation of bulk rock composition due to porphyroblasts growth: effects on eclogite facies mineral equilibria, Pam Peninsula, New Caledonia. J Metamorph Geol 20:151–165CrossRefGoogle Scholar
  26. Massonne H-J (2012) Formation of amphibole and clinozoisite-epidote in eclogite owing to fluid infiltration during exhumation in a subduction channel. J Petrol 53:1969–1998CrossRefGoogle Scholar
  27. Massonne H-J (2013) Constructing the pressure–temperature path of ultrahigh-pressure rocks. Elements 9:267–272CrossRefGoogle Scholar
  28. Massonne H-J (2016) Tertiary high-pressure metamorphism recorded in andalusite-bearing micaschist, southern Pirin Mts., SW Bulgaria. Eur J Mineral 28:1187–1202CrossRefGoogle Scholar
  29. Massonne H-J, Willner AP (2008) Phase relations and dehydration behaviour of psammopelite and mid-ocean ridge basalt at very-low-grade to low-grade metamorphic conditions. Eur J Mineral 20:867–879CrossRefGoogle Scholar
  30. Massonne H-J, Opitz J, Theye T, Nasir S (2013) Evolution of a very deeply subducted metasediment from As Sifah, northeastern coast of Oman. Lithos 156–159:171–185CrossRefGoogle Scholar
  31. Negulescu E (2013) The significance of minerals and mineral assemblages in deriving the metamorphic history of the Leaota Massif crystalline basement. Tehnopress, IaşiGoogle Scholar
  32. Negulescu E, Săbău G (2013) A reappraisal of the P-T evolution of high-pressure tectonic blocks from the Leaota Massif. South Carpathians Rev Roum de Géol 57(1–2):37–56Google Scholar
  33. Negulescu E, Săbău G (2015) Fluid-mediated alteration of eclogite lenses in subduction complexes: a case from the Leaota Massif (South Carpathians)., in: Zellmer GF, Edmonds M, Straub SM (eds). The Role of Volatiles in the Genesis, Evolution and Eruption of Arc Magmas. Geol Soc Lond Spec Publ 410:19–58Google Scholar
  34. Negulescu E, Săbău G, Massonne H-J (2009) Chloritoid-bearing mineral assemblages in high-pressure metapelites from the Bughea Complex, Leaota Massif (South Carpathians). J Petrol 50:103–125CrossRefGoogle Scholar
  35. O’Brien PJ (2011) Unravelling P-T-t paths: pseudo-sections versus classical phase petrology. Mineral Mag 75:1555Google Scholar
  36. Okay AI (2002) Jadeite-chloritoid-glaucophane-lawsonite blueschists in northwest Turkey: unusually high P/T ratios in continental crust. J Metamorph Geol 20:757–768CrossRefGoogle Scholar
  37. Powell R, Holland T (2010) Using equilibrium thermodynamics to understand metamorphism and metamorphic rocks. Elements 6:309–314CrossRefGoogle Scholar
  38. Ring U, Brandon MT, Willet SD, Lister GS (1999) Exhumation processes. In: Ring U, Brandon MT, Lister GS, Willet SD (eds). Exhumation Processes: Normal Faulting, Ductile Flow and Erosion. Geol Soc Lond Spec Publ 154:1–27Google Scholar
  39. Săbău G (2000) A possible UHP-eclogite in the Leaota Mts. (South Carpathians) and its history from high-pressure melting to retrograde inclusion in a subduction melange. Lithos 52:253–276CrossRefGoogle Scholar
  40. Săbău G, Negulescu E (2012) Chemical U-Th-total Pb ages in recycled metamorphic terranes: the case of the South Carpathian basement units. Mineral Mag 76:2310Google Scholar
  41. Săbău G, Negulescu E (2013) Microprobe U-Th-PbT Dating of Monazite: TopDown, Bottom-Up or au Rebours? GSTF J Geol Sci (JGS) 1(1):20–29Google Scholar
  42. Săbău G, Negulescu E (2015) Monazite chemical age and composition correlations, an insight in the Palaeozoic evolution of the Leaota Massif, South Carpathians. Geophys Res Abs 17:EGU2015–E12781Google Scholar
  43. Săbău G, Kasper HU, Dinică I (1997) Geochemical features of the Albeşti Granitoid in the Leaota Massif. Rom J Mineral 78:89–90Google Scholar
  44. Smye AJ, Greenwood LV, Holland TJB (2010) Garnet-chloritoid-kyanite assemblages: eclogite facies indicators of subduction constraints in orogenic belts. J Metamorph Geol 28:753–768CrossRefGoogle Scholar
  45. Stöckhert B, Massonne H-J, Nowlan EU (1997) Low differential stress during high pressure metamorphism: the microstructural record of a metapelite from the eclogite zone, Tauern window, Eastern Alps. Lithos 41:103–118CrossRefGoogle Scholar
  46. Stüwe K (1997) Effective bulk composition changes due to cooling: a model predicting complexities in retrograde reaction textures. Contrib Mineral Petr 129:43–52CrossRefGoogle Scholar
  47. Theye T, Seidel E, Vidal O (1992) Carpholite, sudoite, and chloritoid in low-grade high-pressure metapelites from Crete and the Peloponnese, Greece. Eur J Mineral 4/3:487–508CrossRefGoogle Scholar
  48. Tinkham DK, Zuluaga CA, Stowell HH (2001) Metapelite phase equilibria modeling in MnNCKFMASH: The effect of variable Al2O3 and MgO/(MgO + FeO) on mineral stability. Geol Mater Res 3(1):42Google Scholar
  49. Vaida M (1999) Datarea şi corelarea pe baza asociaţiilor palinologice a formaţiunilor cristalofiliene şi mineralizaţiilor singenetice din partea sudică a Masivului cristalin al Carpaţilor Orientali şi partea estică a Carpaţilor Meridionali. Dissertation, University of IașiGoogle Scholar
  50. Vance D, Holland T (1993) A detailed isotopic and petrological study of a single garnet from the Gassetts Schist, Vermont. Contrib Mineral Petr 114:101–118CrossRefGoogle Scholar
  51. Vance D, Mahar E (1998) Pressure–temperature paths from P–T pseudosections and zoned garnets; potential, limitations and examples from the Zanskar Himalaya, NW India. Contrib Mineral Petr 132:225–245CrossRefGoogle Scholar
  52. Vidal O, Parra T, Trotet F (2001) A thermodynamic model for Fe-Mg aluminous chlorite using data from phase equilibrium experiments and natural pelitic assemblages in the 100° to 600 °C, 1 to 25 kb range. Am J Sci 301:557–592Google Scholar
  53. von Huene R, Ranero C, Vannucchi P (2004) Generic model of subduction erosion. Geology 32:913–916CrossRefGoogle Scholar
  54. Waizenhöfer F, Massonne H-J (2017) Monazite in a Variscan mylonitic paragneiss from the Münchberg Metamorphic Complex (NE Bavaria) records Cadomian protolith ages. J Metamorph Geol 35:453–469CrossRefGoogle Scholar
  55. White RW, Powell R, Holland TJB, Worley BA (2000) The effect of TiO2 and Fe2O3 on metapelitic assemblages at greenschist and amphibolite facies conditions: mineral equilibria calculations in the system K2O-FeO-MgO-Al2O3-SiO2-H2O-TiO2-Fe2O3. J Metamorph Geol 18:497–511CrossRefGoogle Scholar
  56. White RW, Powell R, Holland TJB, Johnson TE, Green ECR (2014) New mineral activity–composition relations for thermodynamic calculations in metapelitic systems. J Metamorph Geol 32:261–286CrossRefGoogle Scholar
  57. Whitney DL, Evans BW (2010) Abbreviations for names of rock-forming minerals. Am Mineral 95:185–187CrossRefGoogle Scholar
  58. Willner AP (2005) Pressure–temperature evolution of a Late Palaeozoic paired metamorphic belt in North–Central Chile (34°–35°30′ S). J Petrol 46:1805–1833CrossRefGoogle Scholar
  59. Zuluaga CA, Stowell HH, Tinkham DK (2005) The effect of zoned garnet on metapelite pseudosection topology and calculated metamorphic P-T paths. Am Mineral 90:1619–1628CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Austria, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Geological Institute of RomaniaBucharest 32Romania
  2. 2.Institut für Mineralogie und Kristallchemie, Universität StuttgartStuttgartGermany

Personalised recommendations