Contributions to Mineralogy and Petrology

, Volume 150, Issue 1, pp 102–118 | Cite as

Fluid evolution during burial and Variscan deformation in the Lower Devonian rocks of the High-Ardenne slate belt (Belgium): sources and causes of high-salinity and C–O–H–N fluids

  • I. Kenis
  • Ph. Muchez
  • G. Verhaert
  • A. Boyce
  • M. Sintubin
Original Paper


Fluid inclusions in quartz veins of the High-Ardenne slate belt have preserved remnants of prograde and retrograde metamorphic fluids. These fluids were examined by petrography, microthermometry and Raman analysis to define the chemical and spatial evolution of the fluids that circulated through the metamorphic area of the High-Ardenne slate belt. The earliest fluid type was a mixed aqueous/gaseous fluid (H2O–NaCl–CO2–(CH4–N2)) occurring in growth zones and as isolated fluid inclusions in both the epizonal and anchizonal part of the metamorphic area. In the central part of the metamorphic area (epizone), in addition to this mixed aqueous/gaseous fluid, primary and isolated fluid inclusions are also filled with a purely gaseous fluid (CO2–N2–CH4). During the Variscan orogeny, the chemical composition of gaseous fluids circulating through the Lower Devonian rocks in the epizonal part of the slate belt, evolved from an earlier CO2–CH4–N2 composition to a later composition enriched in N2. Finally, a late, Variscan aqueous fluid system with a H2O–NaCl composition migrated through the Lower Devonian rocks. This latest type of fluid can be observed in and outside the epizonal metamorphic part of the High-Ardenne slate belt. The chemical composition of the fluids throughout the metamorphic area, shows a direct correlation with the metamorphic grade of the host rock. In general, the proportion of non-polar species (i.e. CO2, CH4, N2) with respect to water and the proportion of non-polar species other than CO2 increase with increasing metamorphic grade within the slate belt. In addition to this spatial evolution of the fluids, the temporal evolution of the gaseous fluids is indicative for a gradual maturation due to metamorphism in the central part of the basin. In addition to the maturity of the metamorphic fluids, the salinity of the aqueous fluids also shows a link with the metamorphic grade of the host-rock. For the earliest and latest fluid inclusions in the anchizonal part of the High-Ardenne slate belt the salinity varies respectively between 0 and 3.5 eq.wt% NaCl and between 0 and 2.7 eq.wt% NaCl, while in the epizonal part the salinity varies between 0.6 and 17 eq.wt% NaCl and between 3 and 10.6 eq.wt% for the earliest and latest aqueous fluid inclusions, respectively. Although high salinity fluids are often attributed to the original sedimentary setting, the increasing salinity of the fluids that circulated through the Lower Devonian rocks in the High-Ardenne slate belt can be directly attributed to regional metamorphism. More specifically the salinity of the primary fluid inclusions is related to hydrolysis reactions of Cl-bearing minerals during prograde metamorphism, while the salinity of the secondary fluid inclusions is rather related to hydration reactions during retrograde metamorphism. The temporal and spatial distribution of the fluids in the High-Ardenne slate belt are indicative for a closed fluid flow system present in the Lower Devonian rocks during burial and Variscan deformation, where fluids were in thermal and chemical equilibrium with the host rock. Such a closed fluid flow system is confirmed by stable isotope study of the veins and their adjacent host rock for which uniform δ180 values of both the veins and their host rock demonstrate a rock-buffered fluid flow system.


Fluid Inclusion Lower Devonian Metamorphic Fluid Metamorphic Zone Gaseous Fluid 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



We thank A.H. Rankin and Jacques Touret for their helpful and constructive comments. Manuel Sintubin is Postdoctoral Fellow of the FWO—Vlaanderen (Belgium). Facilities for the Raman microspectrometer analyses were provided by the Vrije Universiteit Amsterdam and by NOW, the Netherlands Organization for Scientific Research. We thank E. Burke for performing the Raman analyses. Herman Nijs is thanked for careful preparation of the doubly polished thin sections.


  1. Ague JJ (1995) Deep crustal growth of quartz, kyanite and garnet into large-aperture, fluid-filled fractures, north-eastern Connecticut, USA. J Metamorph Geol 13:299–314CrossRefGoogle Scholar
  2. Appel P (1996) Hochdruckgranulite und Eklogite im Mozambique Belt von Tanzania: eine geochemische und petrologische Studie. PhD. Thesis, Universität KielGoogle Scholar
  3. Asselberghs E (1946) L’Eodévonien de l’Ardenne et des régions voisines. Mémoire de l’Institut géologique de l’Université de Louvain 14:1–598Google Scholar
  4. Bakker RJ (1997) Clathrates: computer programs to calculate fluid inclusion V-X properties using clathrate melting temperatures. Comput Geosci 23:1–18CrossRefGoogle Scholar
  5. Beugnies A (1986) Le métamorphisme de l’aire anticlinale de l’Ardenne. Hercynica 2(1):17–33Google Scholar
  6. Bos A, Duit W, van der Eerden AMJ, Jansen JBH (1988) An experimental study on the ammonium and potassium partitioning between one 1 M-phlogopite and vapor at 2 kbar. Geochim Cosmochim Acta 52:1275CrossRefGoogle Scholar
  7. Brown EB (1989) FLINCOR: a microcomputer program for the reduction and investigation of fluid inclusion data. Am Mineral 74:1390–1393Google Scholar
  8. Brown PE, Lamb WM (1989) P-V-T properties of fluids in the system H2O-CO2-NaCl: new graphical presentations and implications for fluid inclusion studies. Geochim Cosmochim Acta 53:1209–1221CrossRefGoogle Scholar
  9. Bucher K, Frey M (1994) Petrogenesis of metamorphic rocks. Springer, Berlin Heidelberg New York, 318 ppGoogle Scholar
  10. Burke EAJ (2001) Raman microspectrometry of fluid inclusions. Lithos 55:139–158CrossRefGoogle Scholar
  11. Burke EAJ, Lustenhouwer WJ (1987) The application of a multichannel laser raman microprobe (Microdil-28(R)) to the analysis of fluid inclusions. Chem Geol 61:11–17CrossRefGoogle Scholar
  12. Chamley H (1989) Clay Sedimentology. Springer, Berlin Heidelberg New York, 623 ppGoogle Scholar
  13. Crawford ML, Filer J, Wood C (1979) Saline fluids inclusions associated with retrograde metamorphism. Bull Mineral 102:562–568Google Scholar
  14. Darimont A (1986) Les inclusions fluides des quartz filoniens d’Ardenne. Annales de la Société géologique de Belgique 109:587–601Google Scholar
  15. Darimont A, Burke EAJ, Touret JLR (1988) Nitrogen-rich metamorphic fluids in devonian metasediments from Bastogne, Belgium. Bulletin de Minéralogie 111:321–330Google Scholar
  16. Dubessy J, Poty B, Ramboz C (1989) Advances in C-O-H-N-S fluid geochemistry based on micro-Raman spectrometric analyses on fluid inclusions. Eur J Mineral 1:517–534Google Scholar
  17. Duit W, Jansen JBH, Van Breemen A, Bos A (1986) Ammonium micas in metamorphic rocks as exemplified by Dome de l’Agout (France). Am J Sci 286:702–732CrossRefGoogle Scholar
  18. Durney DW (1972) Solution-transfer, an important geological deformation mechanism. Nature 235:315–317CrossRefPubMedGoogle Scholar
  19. Eckelmans V (1961) Contribution à l’étude du mètamorphisme et du boudinage dans les roches du Siegénien inférieur de Bastogne. Thèse de mémoire de licence, Université de Liège, 64 ppGoogle Scholar
  20. Edmunds WM, Kay RLF, Miles DL, Cook JM (1987) The origin of saline groundwaters in the Carnmenellis granite, Cornwall (U.K.): further evidence from the minor and trace elements. Geological Association of Canada Special Paper 33:127–142Google Scholar
  21. Eslinger E, Pevear D (1988) Clay minerals for petroleum geologists and engineers. SEPM Short course. Soc Econ Pal Min USA 22Google Scholar
  22. Etheridge MA, Wall VJ, Vernon RH (1983) The role of the fluid phase during regional deformation and metamorphism. J Metamorph Geol 1:205–262CrossRefGoogle Scholar
  23. Everett CE, Wilkinson JJ, Rye DM (1999) Fracture-controlled fluid flow in the Lower Palaeozoic basement rocks of Ireland: implications for the genesis of Irish-type Zn-Pb deposits. In: McCaffrey KJW, Lonergan L, Wilkinson JJ (eds) Fractures, fluid flow and mineralization. Special Publications, Geological Society, London, 155:247–276Google Scholar
  24. Fielitz W, Mansy J-L (1999) Pre- and synorogenic burial metamorphism in the Ardenne and neighbouring areas (Rhenohercynian zone, central European Variscides). In: Sintubin M, Vandycke S, Camelbeeck T (eds) Palaeozoic to recent tectonics in the NW European variscan front zone. Tectonophysics 309:227–256Google Scholar
  25. Fieremans M, Bosmans H (1982) Colour zones and the transition from diagenesis to low-grade metamorphism of the Gedinnian shales around the stavelot Massif (Ardennes, Belgium). Schweiz Mineral Petrogr Mitt 62:99–112Google Scholar
  26. Fitzgerald E, Feely M, Johnston JD, Clayton G, Fitzgerald LJ, Sevastopulo GD (1994) The Variscan thermal history of west Clare, Ireland. Geol Mag 131:545–558CrossRefGoogle Scholar
  27. Glasmacher UA (1995) Stickstoffverteilung in paläozoischen pelitischen gesteinen. In: Walter R, Glasmacher UA, Wolf MA (eds) KW-relevante Eigenschaften potentieller Mutter- undSpeichergesteine am Noordrand des Linksrheinischen Schiefergebirges, Teil II. Potentielle Muttergesteine, Aachen, pp 131Google Scholar
  28. Goldstein RH, Reynolds TJ (1994) Systematics of fluid inclusions in diagenetic minerals. SEPM Short Course 31:1–198Google Scholar
  29. Gregory RT, Gray DR (1994) Oxygen isotope systematics of coexisting veins and whole rocks as tracers of fluid-rock interaction in the crust. Min Mag 58(A):352–352CrossRefGoogle Scholar
  30. Haack UK (1969) Spurenelemente in Biotiten aus Graniten und Gneisen. Contrib Mineral Petrol 22:83–126CrossRefGoogle Scholar
  31. Haack U, Heinrichs H, Boneβ M, Schneider A (1984) Loss of metals from pelites during regional metamorphism. Contrib Mineral Petrol 85:116–132CrossRefGoogle Scholar
  32. Hanor JS (1994) Origin of saline fluids in sedimentary basins. In: Parnell J (ed) Geofluids: migration, and evolution of fluids in sedimentary basins. Geological Society, Special Publications 78:151–174Google Scholar
  33. Hatert F, Fransolet A-M, Houssa M (1996) La Titanite de Bastogne (Belgique) et les minéraux associés. Bulletin de la Société Royale des Sciences de Liège 65:387–397Google Scholar
  34. Hatert F, Deliens M, Houssa M, Coune F (2000) Native gold, native silver, and secondary minerals in the quartz veins from Bastogne, Belgium: Bulletin de l’Institut Royal des Sciences Naturelles de Belgique. Sciences de la Terre 70:223–229Google Scholar
  35. Hunt JM (1979) Petroleum geochemistry and Geology. Freeman, San FransicoGoogle Scholar
  36. Jamtveit B, Yardley BWD (1997) Fluid flow and transport in rocks: an overview. In: Jamtveit B, Yardley BWD (eds) Fluid flow and transport in rocks. Chapman & Hall, London, pp 1–14Google Scholar
  37. Kenis I (2004) Brittle-ductile deformation behaviour in the middle crust as exemplified by mullions (former “boudins”) in the High-Ardenne slate belt. Aardkundige mededelingen 14:127Google Scholar
  38. Kenis I, Muchez P, Sintubin M, Mansy J-L, Lacquement F (2000) The use of a combined structural, stable isotopic and fluid inclusion study to constrain the kinematic history at the northern Variscan front zone (Bettrechies, France). J Struct Geol 22:598–602Google Scholar
  39. Kenis I, Sintubin M, Muchez P, Burke EAJ (2002) The "boudinage" question in the High-Ardenne slate belt (Belgium): a combined structural and fluid inclusions approach. In: Labaume P, Craw D, Lespinasse M, Muchez P (eds) Tectonophysics. pp 93–110Google Scholar
  40. Kenis I, Urai JL, van der Zee W, Sintubin M (2004) Mullions in the High-Ardenne Slate Belt (Belgium): numerical model and parameter sensitivity analysis. J Struct Geol 26:1677–1692CrossRefGoogle Scholar
  41. Kerrich R (1976) Some effects of tectonic recrystallisation of fluid inclusions in vein quartz. Contrib Mineral Petrol 59:195–202CrossRefGoogle Scholar
  42. Klement C (1888) Analyse chimique de quelques minéraux et roches de Belgique et de l’Ardenne française: Bulletin du musée royal d’histoire naturelle de Belgique 5:159Google Scholar
  43. Lee BI, Kesler MG (1975) A generalized thermodynamic correlation between on three-parameters corresponding states. Am Inst Chem Eng J 21:510–521Google Scholar
  44. Lu J, Seccombe PK (1993) Fluid evolution in a slate-belt gold deposit. A fluid inclusion study of the Hill End goldfield, NSW, Australia. Mineral Depos 28:310–323CrossRefGoogle Scholar
  45. Mosar J (1987) Schistosité et métamorphisme hercyniens dans les Ardennes Luxembourgeoises. Sci Géol Bull 40:231–243Google Scholar
  46. Mosar J (1991) S to N increasing low grade metamorphism in the Ardenne Eisleck, Luxembourg. Terra Abstra 3:1–106Google Scholar
  47. Muchez P, Slobodnik M, Sintubin M, Viaene W, Keppens E (1997) Origin and migration of palaeofluids in the Lower Carboniferous of Southern and Eastern Belgium. Zentralblat für Geologie und Paläontologie, Teil I 1995 11(12):1107–1112Google Scholar
  48. Oliver NHS, Bons PD (2001) Mechanisms of fluid flow and fluid-rock interaction in fossil metamorphic hydrothermal systems inferred from vein-wallrock patterns, geometry and microstructure. Geofluids 1:137–162CrossRefGoogle Scholar
  49. Oncken O, von Winterfeld C, Dittmar U (1999) Accretion of a rifted passive margin: the Late Paleozoic Rhenohercynian fold and thrust belt (Middle European Variscides). Tectonics 18(1):75–91CrossRefGoogle Scholar
  50. Phillips GN, Williams PJ, De Jong G (1994) The nature of metamorphic fluids and significance for metal exploration. In: Parnell J (ed) Geofluids: origin, migration and evolution of fluids in sedimentary basins. Geological Society Special Publication 78:55–68Google Scholar
  51. Richards IJ, Connelly JB, Gregory RT, Gray DR (2002) The importance of diffusion, advection and host-rock lithology on vein formation: a stable isotope study from the Paleozoic Ouachita orogenic belt, Arkansas and Oklahoma. Geol Soc Am Bull 114:1343–1355CrossRefGoogle Scholar
  52. Roedder E (1984) Fluid inclusions. In: M.S.O. America (ed) Rev mineral. Washington, pp 644Google Scholar
  53. Russell WL (1933) Subsurface concentration of chloride brines. AAPG Bull 17:2430–2440Google Scholar
  54. Sanchez-Espana J, Velasco F, Boyce AJ, Fallick AE (2003) Source and evolution of ore-forming hydrothermal fluids in the northern Iberian Pyrite Belt massive sulphide deposits (SW Spain): evidence from fluid inclusions and stable isotopes. Mineral Depos 38:519–537CrossRefGoogle Scholar
  55. Scambelluri M, Rampone E, Piccardo G (2001) Fluid and element cycling in subducted serpentinite: a trace-element study of the erro–tobbio high-pressure ultramafites (Western Alps, NW Italy). J Petrol 42:55–67CrossRefGoogle Scholar
  56. Schmidt W (1956) Neue ergebnisse der revisionskartierung des hohen Venns. Beih Geol Jarhb 21:1–146Google Scholar
  57. Schroyen K (2000) Caledonische en Varistische fluïda en de metamorfe evolutie van het Stavelot-Vennmassief. Ph. D. Thesis, Katholieke Universiteit Leuven, Leuven, 276 ppGoogle Scholar
  58. Schroyen K, Muchez P (2000) Evolution of metamorphic fluids at the Variscan fold-and-thrust belt in eastern Belgium. Sediment Geol 131:163–180CrossRefGoogle Scholar
  59. Shepherd TJ, Bottrell SH, Miller MF (1991) Fluid inclusion volatiles as an exploration guide to black shale-hosted gold deposits, Dolgellau gold belt, North Wales, UK. J Geochem Explor 42:5–24CrossRefGoogle Scholar
  60. Sorby HC (1863) On the direct correlation of mechanical and chemical forces. Proc R Soc London 12:538–550Google Scholar
  61. Sorby HC (1865) On impressed limestone pebbles, as illustrating a new principle in chemical geology. West Yorks Geol Soc 14:458–461Google Scholar
  62. Thiéry R, van den Kerkhof AM, Dubessy J (1994) vX properties of CH4-CO2 and CO2-N2 fluid inclusions: modelling for T<31°C and P<400 bars. Eur J Mineral 6:753–771Google Scholar
  63. Tissot BP, Welte DH (1984) Petroleum formation and occurrence. Springer, Berlin Heidelberg New YorkGoogle Scholar
  64. Touray J-C, Bény C, Dubessy J, Guilhaumou N (1985) Microcharacterisation of fluid inclusions in minerals by Raman microprobe. Scann Electron Microsc 1:1003–1018Google Scholar
  65. Urai JL, Spaeth G, van der Zee W, Hilgers C (2001) Evolution of mullion (formerly boudin) structures in the Variscan of the Ardennes and Eifel. J Virtual Explor 3:1–15Google Scholar
  66. Van den Kerkhof AM, Kisch H (1993) CH4-rich inclusions from quartz veins in the Valley-and-Ridge province and the anthracite fields of the Pennsylvania Appalachians-Reply. Amer Mineral 78:220–224Google Scholar
  67. Van den Kerkhof AM, Thiéry R (2001) Carbonic inclusions. Lithos 55:49–68CrossRefGoogle Scholar
  68. Wilkinson JJ (1990) The role of metamorphic fluids in the evolution of the Cornubian orefield: fluid inclusion evidence from south Cornwall. Mineral Mag 54:219–230CrossRefGoogle Scholar
  69. Wilkinson JJ, Jenkin GRT, Fallick AE, Foster RP (1995) Oxygen and hydrogen evolution of Variscan crustal fluids, south Cornwall, UK. Chem Geol (Isotope GeoScience Section) 123:239–254Google Scholar
  70. Yardley BWD (1989) An Introduction to metamorphic petrology. Harlow, Longmans, 248 ppGoogle Scholar
  71. Yardley BWD (1996) The evolution of fluids through the metamorphic cycle. In: Jamtveit B, Yardley BWD (eds) Fluid Flow and Transport in Rocks. Chapman & Hall, London, pp 99–121Google Scholar
  72. Yardley BWD, Graham JT (2002) The origins of salinity in metamorphic fluids. Geofluids 2:249–256CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • I. Kenis
    • 1
  • Ph. Muchez
    • 2
  • G. Verhaert
    • 2
  • A. Boyce
    • 3
  • M. Sintubin
    • 1
  1. 1.Structural Geology and Tectonics GroupK.U.LeuvenLeuvenBelgium
  2. 2.Geodynamics and Geofluids Research Group, Fysico-Chemische GeologieK.U.LeuvenLeuvenBelgium
  3. 3.Isotope Geoscience UnitSURRCGlasgowUK

Personalised recommendations