Advertisement

Mineralium Deposita

, Volume 41, Issue 7, pp 713–733 | Cite as

Origin of the Rubian carbonate-hosted magnesite deposit, Galicia, NW Spain: mineralogical, REE, fluid inclusion and isotope evidence

  • Stephanos P. KiliasEmail author
  • Manuel Pozo
  • Manuel Bustillo
  • Michael G. Stamatakis
  • José P. Calvo
Article

Abstract

The Rubian magnesite deposit (West Asturian—Leonese Zone, Iberian Variscan belt) is hosted by a 100-m-thick folded and metamorphosed Lower Cambrian carbonate/siliciclastic metasedimentary sequence—the Cándana Limestone Formation. It comprises upper (20-m thickness) and lower (17-m thickness) lens-shaped ore bodies separated by 55 m of slates and micaceous schists. The main (lower) magnesite ore body comprises a package of magnesite beds with dolomite-rich intercalations, sandwiched between slates and micaceous schists. In the upper ore body, the magnesite beds are thinner (centimetre scale mainly) and occur between slate beds. Mafic dolerite dykes intrude the mineralisation. The mineralisation passes eastwards into sequence of bedded dolostone (Buxan) and laminated to banded calcitic marble (Mao). These show significant Variscan extensional shearing or fold-related deformation, whereas neither Rubian dolomite nor magnesite show evidence of tectonic disturbance. This suggests that the dolomitisation and magnesite formation postdate the main Variscan deformation. In addition, the morphology of magnesite crystals and primary fluid inclusions indicate that magnesite is a neoformed hydrothermal mineral. Magnesite contains irregularly distributed dolomite inclusions (<50 μm) and these are interpreted as relics of a metasomatically replaced dolostone precursor. The total rare earth element (REE) contents of magnesite are very similar to those of Buxan dolostone but are depleted in light rare earth elements (LREE); heavy rare earth element concentrations are comparable. However, magnesite REE chondrite normalised profiles lack any characteristic anomaly indicative of marine environment. Compared with Mao calcite, magnesite is distinct in terms of both REE concentrations and patterns. Fluid inclusion studies show that the mineralising fluids were MgCl2–NaCl–CaCl2–H2O aqueous brines exhibiting highly variable salinities (3.3 to 29.5 wt.% salts). This may be the result of a combination of fluid mixing, migration of pulses of variable-salinity brines and/or local dissolution and replacement processes of the host dolostone. Fluid inclusion data and comparison with other N Iberian dolostone-hosted metasomatic deposits suggest that Rubian magnesite probably formed at temperatures between 160 and 200°C. This corresponds, at hydrostatic pressure (500 bar), to a depth of formation of ~~5 km. Mineralisation-related Rubian dolomite yields δ 18O values (δ 18O: 12.0–15.4‰, mean: 14.4±1.1‰) depleted by around 5‰ compared with barren Buxan dolomite (δ 18O: 17.1–20.2‰, mean: 19.4±1.0‰). This was interpreted to reflect an influx of 18O-depleted waters accompanied by a temperature increase in a fluid-dominated system. Overlapping calculated δ 18Ofluid values (~+5‰ at 200°C) for fluids in equilibrium with Rubian dolomite and magnesite show that they were formed by the same hydrothermal system at different temperatures. In terms of δ 13C values, Rubian dolomite (δ 13C: −1.4 to 1.9‰, mean: 0.4±1.3‰) and magnesite (δ 13C: −2.3 to 2.4‰, mean: 0.60±1.0‰) generally exhibit more negative δ 13C values compared with Buxan dolomite (δ 13C: −0.2 to 1.9‰, mean: 0.8±0.6‰) and Mao calcite (δ 13C: −0.3 to 1.5‰, mean: 0.6±0.6‰), indicating progressive modification to lower δ 13C values through interaction with hydrothermal fluids. 87Sr/86Sr ratios, calculated at 290 Ma, vary from 0.70849 to 0.70976 for the Mao calcite and from 0.70538 to 0.70880 for the Buxan dolostone. The 87Sr/86Sr ratios in Rubian magnesite are more radiogenic and range from 0.71123 to 0.71494. The combined δ 18O–δ 13C and 87Sr/86Sr data indicate that the magnesite-related fluids were modified basinal brines that have reacted and equilibrated with intercalated siliciclastic rocks. Magnesite formation is genetically linked to regional hydrothermal dolomitisation associated with lithospheric delamination, late-Variscan high heat flow and extensional tectonics in the NW Iberian Belt. A comparison with genetic models for the Puebla de Lillo talc deposits suggests that the formation of hydrothermal replacive magnesite at Rubian resulted from a metasomatic column with magnesite forming at higher fluid/rock ratios than dolomite. In this study, magnesite generation took place via the local reaction of hydrothermal dolostone with the same hydrothermal fluids in very high permeability zones at high fluid/rock ratios (e.g. faults). It was also possibly aided by additional heat from intrusive dykes or sub-cropping igneous bodies. This would locally raise isotherms enabling a transition from the dolomite stability field to that of magnesite.

Keywords

Spain Magnesite Rubian Dolomitisation 

Notes

Acknowledgements

Financial support for this work has been provided by project BTE2001-1443 (Ministerio de Ciencia y Tecnologia). We wish to thank D.P. Rodriguez (Magnesitas de Rubian S.A.) for advising and for facilities given during the development of the investigation, and M. Regueiro and M. Lombardero (IGME) for collaboration during fieldwork. Thanks are also due to J.R. Martínez Catalán, R. Arenas and G. Gutierrez-Alonso for valuable discussions on the regional geology. We thank D.P.F. Darbyshire, NERC Isotope Geoscience Laboratory (NIGL) and J. Naden, British Geological Survey (BGS) for critical and constructive reviews of the manuscript. Acknowledgements are extended to F. Tornos for his critical review that significantly improved the original manuscript. Thanks are extended to geologist K. Detsi (National and Kapodistrian University of Athens-NKUA) for logistic help and to E. Michailidis (NKUA) for technical assistance with SEM–EDS analysis.

References

  1. Aharon P (1988) A stable-isotope study of magnesites from the Rum Jungle Uranium Field, Australia: implications for the origin of strata-bound massive magnesites. Chem Geol 69:127–145CrossRefGoogle Scholar
  2. Aranguren A, Cuevas J, Tubia JM, Roman-Berdiel T, Casas-Sainz A, Casas-Ponsati A (2003) Granite laccolith emplacement in the Iberian arc: AMS and gravity study of the La Tojiza pluton (NW Spain). J Geol Soc (Lond) 60:435–445Google Scholar
  3. Arenas R, Martínez Catalán JR (2003) Low-P metamorphism following a Barrovian-type evolution. Complex tectonic controls for a common transition, as deduced in the Mondoñedo thrust sheet (NW Iberian Massif). Tectonophysics 365:143–164CrossRefGoogle Scholar
  4. Bakker RJ (2001) FLUIDS: new software package to handle microthermometric data and to calculate isochores. In: Noronha F, Doria A, Guedes A (eds) XVI ECROFI European current research on fluid inclusions. Porto 2001, abstracts. Faculdade de Ciencias do Porto, Departamiento de Geologia. Memoria 7:23–25Google Scholar
  5. Bakker RJ (2003) Package FLUIDS 1. Computer programs for analysis of fluid inclusion data and for modelling bulk fluid properties. Chem Geol 194:3–23CrossRefGoogle Scholar
  6. Bakker RJ (2004) Raman spectra of fluid and crystal mixtures in the systems H2O, H2O–NaCl and H2O–MgCl2 at low temperatures: applications to fluid-inclusion research. Can Mineral 42:1283–1314Google Scholar
  7. Banner JL (1995) Application of the trace-element and isotope geochemistry of strontium to studies of carbonate diagenesis. Sedimentology 42:805–824CrossRefGoogle Scholar
  8. Bau M, Moller P (1992) Rare earth element fractionation in metamorphogenic hydrothermal calcite, magnesite and siderite. Mineral Petrol 45:231–246CrossRefGoogle Scholar
  9. Bodnar RJ (1993) Revised equation and table for determining the freezing-point depression of H2O–NaCl solutions. Geochim Cosmochim Acta 57:683–684CrossRefGoogle Scholar
  10. Bodnar RJ, Vityk MO (1994) Interpretation of microthermometric data for H2O–NaCl. In: De Vivo B, Frezzoti ML (eds) Fluid inclusions in minerals. Blacksburg, Virginia Polytechnic Institute, pp 117–130Google Scholar
  11. Boni M, Parente G, Bechstadt T, De Vivo B, Iannace A (2000) Hydrothermal dolomites in SW Sardinia (Italy): evidence for a widespread late-Variscan fluid flow event. Sediment Geol 131:181–200CrossRefGoogle Scholar
  12. Bustillo M, López-Jimeno C (1997) Manual de Evaluación y Diseño de Explotaciones Mineras. Entorno Gráfico, Madrid, p 705Google Scholar
  13. Clyne MA, Potter RW (1977) Freezing point depression of synthetic brines (abstract]. Geological Society of America abstracts with programs, vol 19, p 930Google Scholar
  14. Craig H (1957) Isotopic standards for carbon and oxygen and correction factors for mass spectrometric analysis of carbon dioxide. Geochim Cosmochim Acta 12:133–149CrossRefGoogle Scholar
  15. Crespo TM, Delgado A, Catena EV, García JAL, Fabre C (2002) The latest post-Variscan fluids in the Spanish Central System. Mar Pet Geol 19:323–337CrossRefGoogle Scholar
  16. Dallmeyer RD, Martínez-García E (Eds) (1990) Pre-Mesozoic geology of Iberia. Springer, Berlin Heidelberg New York, p 415Google Scholar
  17. Dallmeyer RD, Martínez Catalán JR, Arenas R, Gil Ibarguchi JI, Gutierrez Alonso G, Farias F, Aller J (1997) Diachronous Variscan tectonothermal activity in the NW Iberian Massif: evidence from 40Ar/39Ar dating of regional fabrics. Tectonophysics 297:307–337CrossRefGoogle Scholar
  18. Davies DW, Lowenstein TK, Spenser RJ (1990) Melting behavior of fluid inclusions in laboratory-grown halite crystals in the systems NaCl–H2O, NaCl–KCl, NaCl–MgCl2–H2O, and NaCl–CaCl2–H2O. Geochim Cosmochim Acta 54:591–601CrossRefGoogle Scholar
  19. Dix GR, Thomson ML, Longstaffe FJ (1995) Systematic decrease of high delta-C-13 values with burial in late Archean (2.8-Ga) diagenetic dolomite—evidence for methanogenesis from the Crixas Greenstone-belt, Brazil. Precambrian Res 70:253–268CrossRefGoogle Scholar
  20. Doval M, Brell JM, Galán E (1977) El yacimiento de magnesita de Incio (Lugo, España). Bol Geol Min 88:50–64Google Scholar
  21. Dubessy J, Derome D, Sausse J (2003) Numerical modelling of fluid mixings in the H2O–NaCl system application to the North Caramal U prospect (Australia). Chem Geol 194:25–39CrossRefGoogle Scholar
  22. Ebneth S, Shields GA, Veizer J, Miller JF, Shergold JH (2001) High-resolution strontium isotope stratigraphy across the Cambrian–Ordovician transition. Geochim Cosmochim Acta 65:2273–2292CrossRefGoogle Scholar
  23. Ellmies R, Voigtlander G, Germann K, Krupenin MT, Moller P (1999) Origin of giant stratabonnd deposits of magnesite and siderite in Riphean carbonate rocks of the Bashkir mega-anticline, western Urals. Geol Rundsch 87:589–602CrossRefGoogle Scholar
  24. Fabricius J (1984) Formation temperature and chemistry of brine inclusions in euhedral quartz crystals from Permian salt in the Danish Trough. Bull Mineral 107:203–216Google Scholar
  25. Faure G (1986) Principles of isotope geology. Wiley, New York, NY, p 589Google Scholar
  26. Fernandez-Nieto C, Torres-Ruiz J, Subias-Perez I, Fanlo-Gonzalez I, Gomzalez-Lopez JM (2003) Genesis of Mg–Fe carbonates from the Sierra Menera magnesite–siderite deposits, northeast Spain: evidence from fluid inclusions, trace elements, rare earth elements, and stable isotope data. Econ Geol 98:1413–1426CrossRefGoogle Scholar
  27. Fernandez-Suarez J, Dunning GR, Jenner GA, Gutierrez-Alonso G (2000) Variscan collisional magmatism and deformation in NW Iberia: constraints from U–Pb geochronology of granitoids. J Geol Soc (Lond) 157:565–576Google Scholar
  28. Friedman I, O’Neil JR (1977) Compilation of stable isotope fractionation factors of geochemical interest. In: Fleischer M (ed) Data of geochemistry. Ch KK US Geol Surv, Prof Pap 440-KK 1–12Google Scholar
  29. Gasparrini M (2003) Large-scale hydrothermal dolomitization in the southwestern Cantabrian Zone (NW Spain): causes and controls of the process and origin of the dolomitization fluids. Ph.D. thesis, University of Heidelberg, p 193Google Scholar
  30. Gasparrini M, Bakker RJ, Bechstadt Th, Boni M (2003) Hot dolomites in a Variscan foreland belt: hydrothermal flow in the Cantabrian Zone (NW Spain). J Geochem Explor 78–79:501–507CrossRefGoogle Scholar
  31. Gómez de Llarena J (1959) Nuevas observaciones sobre la magnesita sedimentaria. Estud Geol 15:189–211Google Scholar
  32. Gomez-Fernandez F, Both RA, Magnas J, Arribas A (2000) Metallogenesis of Zn–Pb carbonate-hosted mineralization in the southeastern region of the Picos de Europa (central northern Spain) province: geologic, fluid inclusion, and stable isotope studies. Econ Geol 95:19–40Google Scholar
  33. Grimmer JOW, Bakker RJ, Zeeh S, Bechstadt T (2000) Dolomitization and brecciation along fault zones in the Cantabrian mountains. J Geochem Explor 69–70:153–158CrossRefGoogle Scholar
  34. Guillou JJ (1970) Les magnesites cambriennes de Pacios (Province de Lugo-Espagne). Leur environnement paléogéographique. Bulletin du Bureau des Recherches Géologiques et Minières (2ème Sér.), sect IV, 3:5–20Google Scholar
  35. Gutierrez-Alonso G, Fernandez-Suarez J, Weil AB (2004) Orocline triggered lothospheric delamination. Geol Soc Amer Bull 383:121–130Google Scholar
  36. Iannace A, Boni M, Bechstadt T (2001) Late Variscan fluid-flow and hydrothermal dolomitisation: an European perspective? In: Piestrzyñski A et al (eds) Mineral deposits at the beggining of the 21st century. pp 197–200Google Scholar
  37. IGME—Instituto Geologico Y Minero de Espana (1983) Geological map of Lugo (geological map of Spain 1/200,000). Instituto Geologico Y Minero de Espana, MadridGoogle Scholar
  38. Johannes W (1970) Zur Entstehung von Magnesitvorkommen. Neues Jahrb Mineral Abh 113:274–325Google Scholar
  39. Kralik M, Aharón P, Schroll E, Zachmann D (1989) Carbon and oxygen isotope systematics of magnesites: a review. In: Möller P (ed) Magnesite geology, mineralogy, geochemistry, formation of Mg-carbonates. Monogr Ser Miner Depos 28:197–223Google Scholar
  40. Leach DL, Apodaca LE, Repetski JE, Powell JW, Rowan EL (1997) Evidence for hot Mississippi Valley-type brines in the Reelfoot rift complex, south-central United States, in late Pennsylvanian–early Permian. US geological survey professional paper 1577, pp 36Google Scholar
  41. Lotze F (1957) Zum Alter nordwestspanischer Quartzit-Sandstein-Folgen. Neues Jahrb Geol Paläontol Monatsh 10:464–471Google Scholar
  42. Lugli S, Torres-Ruiz J, Garuti G, Olmedo F (2000) Petrography and geochemistry of the Eugui magnesite deposit (Western Pyrenees, Spain): evidence for the development of a peculiar zebra banding by dolomite replacement. Econ Geol 95:1775–1791CrossRefGoogle Scholar
  43. Lugli S, Morteani G, Blamart D (2002) Petrographic, REE, fluid inclusion and stable isotope study of magnesite from the Upper Triassic Burano Evaporites (Secchia Valley, northern Apennines): contributions from sedimentary, hydrothermal and metasomatic sources. Miner Depos 37:480–494CrossRefGoogle Scholar
  44. Marcos A, Martínez Catalán JR, Gutiérrez Marco JC, Pérez-Estaún A (2004) Zona Asturoccidental-Leonesa. Estratigrafía y paleogeografía. In: Vera JA (ed) Geología de España. 49–52 SGE-IGME, MadridGoogle Scholar
  45. Martínez Catalán JR, Pablo JG (1978) Geological map of Sarria (sheet nr 124, geological map of Spain 1/50,000). Instituto Geológico Minero de España, MadridGoogle Scholar
  46. Martínez Catalán JR, Perez Estaun A, Bastida F, Pulgar JA (1990) West Asturian-Leonese Zone Structure. In: Dallmeyer RD, Martinez Garcia E (eds) Pre-Mesozoic geology of Iberia. Springer, Berlin Heidelberg New York, pp 103–114Google Scholar
  47. Martínez Catalán JR, Rodríguez MPH, Alonso PV, Pérez-Estaún A, Lodeiro FG (1992) Lower Paleozoic extensional tectonics in the limit between the West Asturian-Leonese and Central Iberian Zones of the Variscan Fold-Belt in NW Spain. Geol Rundsch 81:545–560CrossRefGoogle Scholar
  48. Martínez Catalán JR, Arenas R, Díez Balda M (2003) Large extensional structures developed during emplacement of a crystalline thrust sheet: the Mondoñedo nappe (NW Spain). J Struct Geol 25:1815–1839CrossRefGoogle Scholar
  49. Mathews A, Katz A (1977) Oxygen isotope fractionation during dolomitization of calcium-carbonate. Geochim Cosmochim Acta 41:1431–1438CrossRefGoogle Scholar
  50. McCrea JM (1950) On the isotopic chemistry of carbonates and a paleotemperature scale. J Chem Phys 18:849–857CrossRefGoogle Scholar
  51. Melezhik V, Fallick AE, Medvedev PV, Makarikhin VV (2001) Palaeoproterozoic magnesite: lithological and isotopic evidence for playa/sabkha environments. Sedimentology 48:379–397CrossRefGoogle Scholar
  52. Michalik M (1997) Chlorine containing illites, copper chlorides and other chloride bearing minerals in the Fore-Sudetic copper deposit (Poland). In: Papunen H (ed) Mineral deposits: research and exploration. Rotterdam Balkema, pp 543–546Google Scholar
  53. Möller P (1989) Minor and trace elements in magnesite In: Moller P (ed) Magnesite: geology, mineralogy, geochemistry, formation of Mg-carbonates. Monogr Ser Miner Depos 28:173–196Google Scholar
  54. Moritz RP, Fontbote L, Spangenberg J, Rosas S, Sharp Z, Fontignie D (1996) Sr, C and O isotope systematics in the Pucara basin, central Peru. Comparison between Mississippi Valley-type deposits and barren areas. Miner Depos 31:147–162CrossRefGoogle Scholar
  55. Morteani G, Schley F, Möller P (1983) On the formation of magnesite. In: Schneider HJ (ed) Mineral deposits of the Alps and of the Alpine Epoch in Europe. Springer, Berlin Heidelberg New York, pp 106–116Google Scholar
  56. Naden J (1996) CalcicBrine: a Microsoft Excel 5.0 Add-in for calculating salinities from microthermometric data in the system NaCl–CaCl2–H2O. PACROFI VI, University of Wisconsin (abstact)Google Scholar
  57. Niedermayr G, Beran A, Scheriau-Niedermayr E (1983) Magnesite in Permian and Scythian series of the eastern Alps, Austria, and its petrographic significance. In: Schneider HJ (ed) Mineral deposits of the Alps and of the Alpine Epoch in Europe. Springer, Berlin Heidelberg, New York, pp 105–115Google Scholar
  58. Oakes CS, Bodnar RJ, Simonson JM (1990) The system NaCl–CaCl2–H2O. 1. The ice liquidus at 1 atm total pressure. Geochim Cosmochim Acta 54:603–610CrossRefGoogle Scholar
  59. Ohmoto H (1986) Stable isotope geochemistry of ore-deposits. Rev Miner 16:491–559Google Scholar
  60. Ohmoto H, Rye RO (1979) Isotopes of sulfur and carbon In: Barnes HL (ed) Geochemistry of hydrothermal ore deposits Wiley, pp 509–567Google Scholar
  61. Paniagua A, Fontbote J, Fenoll P, Fallick AE, Moreiras D, Corretge L (1993) Tectonic setting, mineralogical characteristics, geochemical signatures and age dating of a new type of epithermal carbonate-hosted, precious metal-five element deposits: the Villamanin area, Cantabrian zone, (Northern Spain). In: Fenoll P, Torres J, Gervillia F (eds) Current research in geology applied to ore deposits. Granada, pp 531–534Google Scholar
  62. Perry EC, Tan FC (1972) Significance of oxygen and carbon isotope determinations in early Precambrian cherts and carbonate rocks in southern Africa. Bull Geol Soc Am 83:647–664Google Scholar
  63. Plumlee GS, Leach DL, Hofstra AH, Landis GP, Rowan EL, Viets JG (1994) Chemical reaction path modeling of ore deposition in Mississippi Valley-type Pb–Zn deposits of the Ozark Region, U.S. Midcontinent. Econ Geol 89:1361–1383CrossRefGoogle Scholar
  64. Pohl W (1990) Genesis of magnesite deposits—models and trends. Geol Rundschau 79/2:291–299CrossRefGoogle Scholar
  65. Pohl W, Siegl W (1986) Sediment-hosted magnesite deposits. In: Wolf KH (ed) Handbook of stratabound and stratiform ore deposits. Elsevier, Amsterdam, 14:223–310Google Scholar
  66. Roedder E (1984) Fluid inclusions. Rev Miner 12:644Google Scholar
  67. Rosenbaum J, Sheppard SMF (1986) An isotopic study of siderites, dolomites and ankerites at high-temperatures. Geochim Cosmochim Acta 50:1147–1150CrossRefGoogle Scholar
  68. Sanchez-España J, Garcia de Cortazar A, Gil P, Velasco F (2002) The discovery of the Borobia world-class stratiform magnesite deposit (Soria, Spain): a preliminary report. Miner Depos 37:240–243CrossRefGoogle Scholar
  69. Schultz LG (1964) Quantitative interpretation of mineralogical composition from X-ray and chemical data for the Pierre Shale. U.S. Geol. Surv., Prof. paper 391-C:31Google Scholar
  70. Sheppard SMF, Schwarz HP (1970) Fractionation of carbon and oxygen isotopes and magnesium between coexisting metamorphic calcite and dolomite. Contrib Mineral Petrol 26:161–198CrossRefGoogle Scholar
  71. Sibley DF, Gregg JM (1987) Classification of dolomite rock textures. J Sediment Petrol 44:967–975Google Scholar
  72. Spiro B, Tornos F, Shepherd TJ (1995) Stable isotope characterization of barren and mineralized tardi-Hercynian hydrothermal carbonates in the Cantabrian zone (N Spain). In: Pasava J, Kribek B, Zak K (eds) Mineral deposits: from their origin to environmental impacts. Rotterdam, Balkema, pp 75–78Google Scholar
  73. Stamatakis MG (1995) Occurrence and genesis of huntite hydromagnesite assemblages, Kozani, Greece—important new white fillers and extenders. Trans Inst Min Metall 104:b179–b186Google Scholar
  74. Sun SS, McDonough WF (1989) Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. In: Saunders AD, Norry MJ (eds) Magmatism in the ocean basins. Geological Society of London, Special Publication 42, pp 313–345Google Scholar
  75. Tornos F, Spiro BF (2000) The geology and isotope geochemistry of the talc deposits of Puebla de Lillo (Cantabrian Zone, Northern Spain). Econ Geol 95(6):1277–1296CrossRefGoogle Scholar
  76. Valley JW (1986) Stable isotope geochemistry of metamorphic rocks. Rev Miner 16:445–486Google Scholar
  77. Vanko DA, Bodnar RJ, Sterner SM (1988) Syhthetic fluid inclusions 8. Vapor saturated halite solubility in part of the system NaCl–CaCl2–H2O, with application to fluid inclusions from oceanic hydrothermal systems. Geochim Cosmochim Acta 52:2451–2456CrossRefGoogle Scholar
  78. Veizer J, Hoefs J (1976) The nature of O18/O16 and C13/C12 secular trends in sedimentary carbonate rocks. Geochim Cosmochim Acta 40:1387–1395CrossRefGoogle Scholar
  79. Veizer J, Ala D, Azmy K, Bruckschen P, Buhl D, Bruhn F, Carden GAF, Diener A, Ebneth S, Godderis Y, Jasper T, Korte G, Pawellek F, Podlaha OG, Strauss H (1999) Sr-87/Sr-86, δ C13 and δO18 evolution of Phanerozoic seawater. Chem Geol 161:59–88CrossRefGoogle Scholar
  80. Velasco F, Pesquera A, Arce R, Olmedo F (1987) A contribution to the ore genesis of the magnesite deposit of Eugui, Navarra (Spain). Miner Depos 22:33–41CrossRefGoogle Scholar
  81. Velasco F, Herrero JM, Yusta I, Alonso JA, Seebold I, Leach D (2003) Geology and geochemistry of the Reocin zinc–lead deposit, Basque-Cantabrian basin, northern Spain. Econ Geol 98:1371–1396CrossRefGoogle Scholar
  82. Walter R (1968) Die Geologie in der Nordöstlichen Provinz Lugo ((Nordwest Spanien). Geotekton Forsch 27:3–70Google Scholar
  83. Zheng YF (1999) Oxygen isotope fractionation in carbonate and sulfate minerals. Geochem J 33:109–126Google Scholar

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Stephanos P. Kilias
    • 1
    Email author
  • Manuel Pozo
    • 2
  • Manuel Bustillo
    • 3
  • Michael G. Stamatakis
    • 1
  • José P. Calvo
    • 4
  1. 1.Department of Economic Geology and Geochemistry, Faculty of Geology and GeoenvironmentNational and Kapodistrian University of Athens (NKUA)AthensGreece
  2. 2.Departamento de Quimica Agricola, Geología y GeoquímicaUniversidad AutónomaCantoblancoSpain
  3. 3.Departamento de Petrología y GeoquímicaUniversidad ComplutenseMadridSpain
  4. 4.Instituto Geologico y Minero de EspanaMadridSpain

Personalised recommendations