Hostname: page-component-848d4c4894-xm8r8 Total loading time: 0 Render date: 2024-07-07T13:55:37.745Z Has data issue: false hasContentIssue false
  • English
  • Français

Geochemistry of a high-T hydrothermal dolostone from the Emirli (Ödemiş, western Turkey) Sb-Au deposit

Published online by Cambridge University Press:  05 July 2018

M. Akçay ,
H. M. Özkan ,
B. Spiro ,
R. Wilson  and
P. W. O. Hoskin
M. Akçay*
Affiliation:
Karadeniz Teknik Üniversitesi, Jeoloji Müh. Böl. 61080 Trabzon, Turkey
B. Spiro
Affiliation:
NERC Isotope Geosciences Laboratory, Keyworth, Nottingham NG12 5G, UK
R. Wilson
Affiliation:
Department of Geology, University of Leicester, Leicester LE1 7RH, UK
P. W. O. Hoskin
Affiliation:
Institut für Mineralogie, Petrologie und Geochemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 23 B, D-79104 Freiburg im Breisgau, Germany
*
* E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

A dolostone layer is found in spatial association with the Emirli epithermal Sb-Au deposit in western Turkey. It occurs within an argillic alteration zone adjacent to the major Emirli fault zone, which is the controlling structure for the deposit, and is composed of large closely packed subhedral to anhedral planar and nonplanar dolomites. Pyrite is the only accessory mineral in the layer and occurs as disseminations and veinlets up to 100 μm wide. Dolomite crystals are petrographically homogeneous and have consistent deep-red cathodoluminescence (CL) colour with no zoning which implies single-stage dolomitization of a calcitic precursor which is partly preserved as remnant patches of orange-coloured CL zones. Some crystal boundaries have dark (or no) CL colour. Electron microprobe line-scan analyses across these regions indicate intense enrichment of Fe and Mg depletion, revealing late-stage Fe-metasomatism (ankeritization) especially prevalent near pyrite veinlets and disseminations.

Dolomite crystals are composed of 52.4–55.0 mol.% CaCO3, 29.9 –41.2 mol.% MgCO3, 1.8 – 14.4 mol.% FeCO3 and 0.75 –3.2 mol.% MnCO3 indicating ferroan dolomite. The relationship between Ca and Mg is not stoichiometric due to substitution of Mg2+ by Fe2+ after dolomitization, as demonstrated by a strong negative correlation between Fe and Mg. Whole-rock Fe contents of the dolostone layer increases toward the Emirli fault zone.

The δ13C(PDB) compositions of the Emirli dolomite, calcitic marbles, and graphite-schists are in the ranges of –1.6 to 0.8‰, 1.5 to 1.5‰ and –6.6 to –23.5%, respectively, indicating that dolomite was formed due to interaction of light-carbon-enriched fluids with calcitic marbles; light-carbon may have been derived from decarboxylation of the graphitic schist layers. δ18O(PDB) values of dolomite and marble range –15.2 to – 11.2‰ and –2.4 to – 3.5‰, respectively. This large isotopic difference between dolomite and marble was probably inherited from oxygen isotope exchange between the dolomitizing fluid and the precursor calcites, as well as other minerals enriched in light-oxygen.

Fluid inclusions in dolomite are two-phase, and homogenize into liquid within the temperature interval 242 – 362ºC with a mode of 290ºC, and have salinities of 1 – 3 wt.% NaCl equiv. Using this modal temperature, the average δ18O(PDB) composition of water in isotopic equilibrium with the Emirli dolostone was estimated to be –19.4±2.1‰, which is interpreted as an indication of modified surface-waters; this interpretation is also supported by low fluid salinity and Na and Sr contents. These fluids migrated along graben-related faults, penetrating deeper levels where they were transformed into hydrothermal fluids due to the high heat-flow of the Küçük Menderes graben system, and flowed-up mainly through the Emirli and Haliköy faults that control mineralization in local deposits of Sb-Au and Hg, respectively. Due to interaction with chlorite-bearing graphite-schists, the fluid may have dissolved Mg2+ from chlorite and been enriched in isotopically-light carbon due to decarboxylation of graphite. Dolomitization occurred as a result of the interaction of these fluids with a calcitic marble band adjacent to the Emirli fault zone. Subsequent introduction of Fe2+ caused ankeritization along dolomite crystal boundaries during first-stage Sb-Au mineralization.

Keywords

hydrothermal dolomitedolostonestibniteSb-Au depositEmirliTurkey.
Type
Research Article
Information
Mineralogical Magazine , Volume 67 , Issue 4 , August 2003 , pp. 671 - 688
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2003

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

†

Deceased

References

Akçay, M., özkan, H.M., Moon, C.J. and Spiro, B. (1997 Fracture controlled and stratabound stibnite, and cinnabar deposits of western Turkey: a genetic approach. Pp. 37—40 in: Mineral Deposits: Research and Exploration, Where Do They Meet (Papunen, H., editor). Balkema, Rotterdam, The Netherlands.Google Scholar
Akkök, R., Satir, M. and Şengör, A.M.C. (1984 Timing of tectonic events in the Menderes massif and its implications. Pp. 93—94 in: Ketin Symposium (Ercan, T. and çaǵlayan, M.A., editors). Turkish Geological Society, Ankara.Google Scholar
Arthur, M.A., Anderson, F.T., Kaplan, R.I., Vezier, J. and Land, L.S. (1983 Stable isotopes in sedimentary geology. SEPM Short Course 10, Dallas, Texas, USA.Google Scholar
Baum, G.R., Harris, W.B. and Drez, P.E. (1985 Origin of dolomite in the Eocene Castle Hayne Limestone, North Carolina. Journal of Sedimentary Petrology, 55, 506—517.Google Scholar
Bodnar, R.J., Reynolds, T.J. and Kuehn, C.A. (1986 Fluid inclusion systematics in epithermal systems. Pp. 73—98 in: Geology and Geochemistry of Epithermal Systems (Berger, B.R. and Bethke, P.M., editors). Reviews in Economic Geology 2, Society of Economic Geologists, Tulsa, OK, USA.Google Scholar
Bozkurt, E. and Park, R.G. (1994 Southern Menderes Massif: an incipient metamorphic core complex in western Anatolia, Turkey. Journal of the Geological Society of London, 151, 213—216.CrossRefGoogle Scholar
Bozkurt, E., Park, R.G. and Winchester, J.A. (1993 Evidence against the core/cover interpretation of the southern sector of the Menderes Massif (West Turkey). Terra Nova,, 5, 445—451.CrossRefGoogle Scholar
Buchbinder, L.G., Magaritz, M. and Goldberg, M. (1984 Stable isotope study of karstic-related dolomitization: Jurassic rocks from the coastal plain. Israeli Journal of Sedimentary Petrology, 54, 236—256.Google Scholar
çaǵlayan, M.A., öztürk, E.M., öztürk, Z., Sav, H. and Akat, U. (1980 Findings on the southern part of the Menderes massif and structural interpretation. Geological Engineering, 25, 9—17.[in Turkish].Google Scholar
Dechomets, R. (1985 Sur l’origine de la pyrite et des skarns du gisement, en contexte evaporitique, de Niccioleta (Toscane, Italie). Mineralium Deposita, 20, 201—210.[in French].CrossRefGoogle Scholar
Deer, W.A., Howie, R.A. and Zussman, J. (1992 An Introduction to the Rock-forming Minerals , 2nd edition. Longman Scientific and Technical, Harlow, Essex, UK.Google Scholar
Dora, O.ö., Kun, N. and Candan, O. (1992 Geotectonic position and metamorphic history of the Menderes massif. Geological Bulletin of Turkey, 35, 1—14.Google Scholar
Fallick, A.E., Ilich, M. and Russel, M.J. (1991 A stable isotopic study of the magnesite deposits associated with the Alpine-type ultramatic rocks of Yugoslavia. Economic Geology, 86, 847—891.CrossRefGoogle Scholar
Faure, G. (1986 Principles of Isotope Geology, 2nd edition. John Wiley & Sons, New York.Google Scholar
Fournier, R.O. (1986 Carbonate transport and deposition in the epithermal environment. Pp. 63—72 in: Geology and Geochemistry of Epithermal Systems (Berger, B.R. and Bethke, P.M., editors). Reviews in Economic Geology 2, Society of Economic Geologists, Tulsa, OK, USA.Google Scholar
Gawthorpe, R.L. (1987 Burial dolomitization and porosity development in a mixed carbonate-clastic sequence: an example from the Bowland Basin, northern England. Sedimentology, 34, 533—558.CrossRefGoogle Scholar
Gillhaus, A., Richter, D.K., Meijer, J., Neuser, R.D. and Stephan, A. (2001 Quantitative high resolution cathodoluminescence spectroscopy of diagenetic and hydrothermal dolomites. Sedimentary Geology, 140, 191—199.CrossRefGoogle Scholar
Gomez-Fernandez, F., Both, R.A., Mangas, J. and 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. Economic Geology, 95, 19—39.CrossRefGoogle Scholar
Gökçe, A. and Spiro, B. (1995 Sulfur isotopes of the antimony and mercury deposits in Beydag (Izmir; Western Turkey) area and the origin of the sulfur in stibnite and cinnabar. Turkish Journal of Earth Sciences, 4, 29—37.Google Scholar
Gregg, J.M. and Sibley, D.F. (1984 Epigenetic dolomitization and the origin of xenotopic dolomite texture. Journal of Sedimentary Petrology, 54, 908—931.Google Scholar
Heroux, Y., Chagnon, A. and Savard, M. (1996 Organic matter and clay anomalies associated with base metal sulphide deposits. Ore Geology Review, 11, 157—173.CrossRefGoogle Scholar
Hetzel, R., Passchier, C.W., Ring, U. and Dora, ö. (1995 Bivergent extension in orogenic belts: the Menderes massif (Southwestern Turkey). Geology, 23, 455—458.2.3.CO;2>CrossRefGoogle Scholar
Hitzman, M.W., Allan, J.R. and Beaty, D.W. (1998 Regional dolomitization of the Waulsortian limestone in southeastern Ireland: evidence of large scale fluid flow driven by the Hercynian orogeny. Geology, 26, 547—550.2.3.CO;2>CrossRefGoogle Scholar
Hoefs, J. (1973 Stable Isotope Geochemistry . Springer-Verlag, Berlin, 140 pp.CrossRefGoogle Scholar
Hurlbut, C.S., Jr. and Klein, C. (1977 Manual of Mineralogy , 19th edition. John Wiley and Sons, New York.Google Scholar
Jones, H.D., Kesler, S.E., Furman, F.C. and Kyle, J.R. (1996 Sulphur isotope geochemistry of southern Appalachian Mississippi Valley-Type deposits. Economic Geology, 91, 355—367.CrossRefGoogle Scholar
Kupecz, J.A. and Land, L.S. (1991 Late-stage do lomi tiz atio n of the Lower Ord ovici an Ellenburg er Group, West Texas. Journal of Sedimentary Petrology, 61, 551—574.Google Scholar
Land, L.S. and Hoops, G.K. (1973 Sodium in carbonate sediments and rocks: a possible index to salinity of diageneti c solutions. Journal of Sediment ary Petrology, 43, 614—617.Google Scholar
Lugli, S., Morteani, G. and 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. Mineralium Deposita, 37, 480—494.CrossRefGoogle Scholar
Mazurov, M.P. and Titov, A.T. (1999 Magnesian skarns from the sites of layer-by-layer injections of basic magma into the evaporites of the platforms’ sedimentary cover. Geologiya i Geofizika, 40, 82—89.(in Russian).Google Scholar
McHarque, T.R. and Price, R.C. (1982 Dolomite from clay in argillaceous or shale associated marine carbonates. Journal of Sedimentary Petrology, 52, 873—886.Google Scholar
Meinert, L.D. (1993 Igneous petrogenesis and skarn deposits. Pp. 569—583 in: Mineral Deposit Modeling (Kirkham, R.V., Sinclair, W.D., Thorpe, R.I. and Duke, J.M., editors). Geological Association of Canada Special Paper 40.Google Scholar
Morteani, G., Möller, P. and Schley, F. (1982 The rare earth element contents and the origin of the sparry magnesite mineralisa tions of Tux-Lanersbach, Entachen Alm, Spiessnagel, and Hochfilzen, Austria, and the lacustrine magnesite deposits of Aiani-Kozani, Greece, and Bela Stena, Yugoslavia. Economic Geology, 77, 617—631.CrossRefGoogle Scholar
Northrop, D.A. and Clayton, R.N. (1966 Oxygenisotope fractionation in systems containing dolomite. Journal of Geology, 74, 174—196.CrossRefGoogle Scholar
özgür, N., Halbach, P., Pakdeǵer, A., Jarmersted, C.S., Sönmez, N., Dora, O.ö., Ma, D.S., Wolf, M. and Stichler, W. (1997 Epithermal antimony, mercury and gold deposits in the continental rift zone of the Küçük Menderes, western Anatolia, Turkey: Preliminary studies. Pp. 268—272 in: Mineral Deposits: Reseach and Exploration, Where Do They Meet (Papunen, H., editor ). Balkema, Rotterdam, The Netherlands.Google Scholar
özkan, H.M., Akçay, M., Moon, C.J. and Scott, B.C. (1993 Genesis of strata-bound and structurecontrolled antimony mineraliza tion at Emirli, Menderes massif, West Turkey (I – Geology, structure, gold and trace element geochemistry). Abstracts of the Geological Congress of Turkey 1993 . Ankara, Turkey, pp. 36—37.Google Scholar
Potter, R.W, Clynne, M.A. and Brown, D.L. (1978 Freezing point depression of aqueous sodium chloride solutions. Economic Geology, 73, 284—285.CrossRefGoogle Scholar
Roedder, E. (1984 Fluid Inclusions . Reviews in Mineralogy 12, Mineralogical Society of America, Washington, D.C.Google Scholar
Rosenbaum, J. and Sheppard, S.S.M. (1986 An isotopic study of siderites, dolomites and ankerites at high temperatures. Geochimica et Cosmochima Acta, 50, 1147—1150.CrossRefGoogle Scholar
Satõr, M. and Friedrichsen, H. (1986 The origin and evolution of the Menderes massif, West Turkey: a rubidium/strontium and oxygen isotope study. Geologische Rundschau, 75, 703—714.CrossRefGoogle Scholar
Seyitoǵlu, G. and Scott, B.C. (1991 Late Cenozoic crustal extension and basin formation in west Turkey. Geological Magazine, 128, 155—166.CrossRefGoogle Scholar
Seyitoǵlu, G. and Scott, B.C. (1992 Late Cenozoic volcanic evolution of the northeastern Aegean region. Journal of Volcanology and Geothermal Research, 54, 157—176.CrossRefGoogle Scholar
Shepherd, T.J., Rankin, A.H. and Alderton, D.D.H. (1985 A Practical Guide to Fluid Inclusion Studies . Blackie, Glasgow, UK.Google Scholar
Shikazono, N., Hoshino, M., Utada, M., Nakata, M. and Ueda, A. (1998 Hydrothermal carbonates in altered wall rocks at the Uwamuki Kuroko deposits, Japan. Mineralium Deposita, 33, 346—358.CrossRefGoogle Scholar
Sibley, D.F. and Gregg, J.M. (1987 Classification of dolomite rock textures. Journal of Sedimentary Petrology, 57, 967—975.Google Scholar
Şengör, A.M.C. and Yilmaz, Y. (1981 Tethyan evolution of Turkey. Tectonophysics, 75, 181—241.CrossRefGoogle Scholar
Şengör, A.M.C., Satõr, M. and Akkök, R. (1984 Timing of tectonic events in the Menderes massif, western Turkey: Implications for tectonic evolution and evidence for Pan-African basement in Turkey. Tectonics, 3, 693—707.CrossRefGoogle Scholar
Taylor, H.P., Jr. (1974 The application of oxygen and hydrogen isotope studies to problems of hydrothermal alteration and ore deposition. Economic Geology, 69, 843—883.CrossRefGoogle Scholar
Taylor, T.R. and Sibley, D.F. (1986 Petrographic and geochemical characteristics of dolomite types and the origin of ferroan dolomite in the Trenton Formation, Ordovician, Michigan Basin, U.S.A. Sedimentology, 33, 61—86.CrossRefGoogle Scholar
Thompson, T.B. (1998 Geology and geochemistry of the Kokomo Mining District, Colorado. Economic Geology, 93, 617—638.Google Scholar
Tucker, M.E. and Wright, V.P. (1992 Carbonate Sedimentology . Blackwell Scientific Publications, Oxford, UK.Google Scholar
Wallace, M.W. (1990 Origin of dolomitization on the Barbwire Terrace, Canning Basin, Western Australia. Sedimentology, 37, 105—122.CrossRefGoogle Scholar
Warren, J. (1999 Evaporites: their Evolution and Economics . Blackwell Scientific Publications, Oxford, UK.Google Scholar
Warren, J. (2000 Dolomite: occurrence, evolution and economically important associations. Earth Science Reviews, 52, 1—81.CrossRefGoogle Scholar
Wilkinson, J.J. and Earls, G. (2000 A high temperature hydrothermal origin for black dolomite matrix breccias in the Irish Zn-Pb ore . eld. Mineralogical Magazine, 64, 1017—1036.CrossRefGoogle Scholar
Yao, Q.J. and Domicco, R.V. (1997 Dolomitization of the Cambrian carbona te platform, Southern Canadian Rocky Mountains: Dolomite from geometry, fluid inclusion geochemistry, isotopic signature, and hydrogeologic modeling studies. American Journal of Science, 297, 892—938.CrossRefGoogle Scholar
Zedef, V., Russell, M.J., Fallick, A.E. and Hall, A.J. (2000 Genesis of vein stockwork and sedimentary magnesite and hydromagnesite deposits in the ultramafic terranes of southwestern Turkey: a stable isotope study. Economic Geology, 95, 429—446.CrossRefGoogle Scholar

A correction has been issued for this article:

Errata