Savcılıebeyit (Kaman-Kırşehir) Gold Mineralization and Its Genetic Relationship With Post-Collisional Exhumation and Extensional Tectonics in Central Anatolia, Turkey

Yıl 2018, Cilt: 39 Sayı: 3, 155 - 176, 27.12.2018

Yurdal Genç , Mehmet Tekin Yürür

https://doi.org/10.17824/yerbilimleri.503711

Öz

    Gold exploration works in central Anatolia, Turkey, were intensified during the last decade, and potentially important gold mineralizations were discovered. In the region, important gold discoveries hosted by metamorphic and granitic rocks are, in the west, Savcılıebeyit and Terziali (Kırşehir), in the middle part, Himmetdede and Mahmatlar (Kayseri), Akçataş (Nevşehir), and at the south-east, Gümüşler (Niğde) mineralizations. The Savcılıebeyit gold mineralization consists mainly of gold-quartz veins, and is the first discovered gold enrichment hosted by metamorphic rocks of west-central Anatolia. These veins are situated at the south-eastern margin of the Cefalıkdağ-Baranadağ granite-migmatite dome, at 60 km west of the city of Kırşehir. In this study, preliminary results of geological and structural investigations of the gold-quartz veins are presented. 

    The study area is part of the Palaeozoic-Mesozoic Kırşehir Massif that comprises mainly high-grade metamorphic and plutonic rocks covered by Cenozoic sediments. The gold-quartz veins are hosted by migmatite, migmatitic gneiss, gneiss-schist-marble intercalations, calc-silicate gneiss and marble. Quartz veins are discordant with respect to the foliation and major lithologic boundaries, and have sharp contacts with the enclosing metamorphic wall rocks. Veins occur as single or composite, relatively continuous veins that are up to about 2 km long and extend for at least 200 m down dip. Their thickness ranges from a few millimetres to two metres.

    The gold-quartz veins consist mainly of quartz, arsenopyrite, pyrite and secondary haematite and limonite. Other common minerals in the veins are calcite, muscovite, biotite, chlorite and epidote. The distribution of gold is erratic, and only weathered, haematite- and limonite-rich parts of the veins near the surface consistently display higher gold contents. Homogenisation temperatures obtained from fluid inclusions in the quartz vein have a wide range, from 160˚C to well above 400˚C. The fluid inclusions are generally rich in carbon dioxide and also have high salinities (20-33 % NaCl equivalent). The gold-quartz veins have many similarities to orogenic gold deposits in terms of metal associations, wall-rock alteration assemblages, mineralogy, formation conditions and structural control. The spatial association of the veins with migmatites, high-grade metamorphic rocks and granitoids suggests an origin related to metamorphism, uplift and/or migmatite doming and granitoid emplacement in central Anatolia.

Anahtar Kelimeler

Granitoid-migmatite doming, Kırşehir Massif, orogenic gold deposit, Turkey

Kaynakça

• Akçay M., 1994. Genesis of the stibnite-cinnabar-scheelite deposits of the Gümüşler area, Niğde, central Turkey and implications for their gold potential. Ph.D thesis, University of Leicester, 241pp. (unpublished).
• Ataman G. 1972. Etude préliminaire sur l’âge radiométrique de Cefalıkdağ massif, l’un des massifs granitique-granodioritique au sud-est d’Ankara. Hacettepe Fen ve Mühendislik Bilimleri Dergisi 2(1): 44-49 (in Turkish with French abstract).
• Aydın SN. and Önen AP., 1999. Field, petrographic and geochemical features of the Baranadağ quartz monzonite of the Central Anatolian Granitoids, Turkey. Turk. J. Earth Sci. 8: 113-123.
• Ayan M., 1963. Contribution à l´étude petrographique et géologique de la region située au Nord-Est de Kaman. MTA publ. 115: 332 pp.
• Bellot JP, Lerouge C, Bailly L and Bouchot V., 2003. The Biards Sb-Au-bearing shear zone (Massif Central, France): an indicator of crustal-scale transcurrent tectonic guiding Late Variscan collapse. Economic Geology 98: 1427-1447.
• Bennett DG and Barker AJ., 1992. High salinity fluids: The results of retrograde metamorphism in thrust zones. Geochimica et Cosmochimica Acta 56: 81-95.
• Bierlein FP, Fuller T, Stüwe K, Arne DC and Keays RR., 1998. Wallrock alteration associated with turbidite-hosted gold deposits. Examples from the Palaeozoic Lachlan Fold Belt in central Victoria, Australia. Ore Geology Reviews 13: 345-380.
• Boiron MC, Cathelineau M, Banks DA, Yardley BWD, Noronha F, Miller FM., 1996. P-T-X conditions of late Hercynian fluid penetration and the origin of granite-hosted gold quartz veins in northwestern Iberia: A multidisciplinary study of fluid inclusions and their chemistry. Geochimica et Cosmochimica Acta 60: 43-57.
• Boiron MC., Cathelineau M., Banks DA., Fourcade S., Vallance J., 2003. Mixing of metamorphic and surficial fluids during the uplift of the Hercynian upper crust: consequences for gold deposition. Chemical Geology 194: 119-141.
• Bouchot V, Milesi JP and Ledru P., 2000. Crustal-scale hydrothermal palaeofield and related variscan Au, Sb, W orogenic deposits at 310-305 Ma (French Massif Central, Variscan Belt). SGA News 10: 1-12.
• Brinkmann R., 1971. Das kristalline Grundgebirge von Anatolien. Geologische Rundschau 60: 886-899.
• Brinkmann R., 1976. Geology of Turkey. Elsevier, Amsterdam, 158 pp.
• Bucher K and Frey M., 1994. Petrogenesis of metamorphic rocks. Springer, Heidelberg, 318 pp.
• Cameron EM., 1988. Archean gold: Relation to granulite formation and redox zoning in the crust. Geology 16: 109-112.
• Coşkun Delibaş E and Genç Y., 2004. Terziali-Çayağzı (Kırşehir) gold mineralization: initial findings of saprolitic gold enrichments in Kırşehir Massif. Yerbilimleri 30: 23-33 (in Turkish with English abstract).
• Eilu PK, Mathison CI, Groves DI and Allardyce WJ., 1999. Atlas of alteration assemblages, styles and zoning in orogenic lode-gold deposits in a variety of host rock and metamorphic setting, Geology and Geophysics Department (Centre for Strategic Mineral Deposits) and UWA Extension, The University of Western Australia Publication 30: 50pp.
• Erkan Y., 1976. Isograds determined in the regional metamorphic area surrounding Kırşehir and their petrological interpretation. Yerbilimleri 2(1): 23-54 (in Turkish with English abstract).
• Erkan Y., 1980. A study on regional metamorphism of northeastern part of Central Anatolian Massif (Akdağmadeni, Yozgat). Bulletin of the Geological Society of Turkey 23: 213-218 (in Turkish with English abstract).
• Erkan Y and Ataman G., 1981. A study on the age of metamorphism of Central Anatolian Massif (Kırşehir region) by K-Ar method. Yerbilimleri 8: 27-30 (in Turkish with English abstract).
• Fayon AK, Whitney DL and Dilek Y., 1999. Constraints on the transition from Alpine crustal thickening to extension in central Anatolia. EOS 80, 1066.
• Fyon JA, Crocket JH and Schwarcz HP., 1984. The Carshaw and Malga iron-formation- hosted gold deposits of the Timmins area. In: Colvine AC (ed.) The Geology of Gold in Ontario. Ontario Geological Survey Miscellaneous Paper 110: 98-110.
• Genç Y., 2001. The metamorphic textures and structures in the Başçatak (Akdağmadeni-Yozgat) Zn-Pb-Cu sulphide deposit, 54th Geological Congress of Turkey, Proceedings CD, 54-51 (in Turkish with English abstract).
• Genç Y and Türkmen H., 2002. Gold-quartz veins in Kırşehir Metamorphic Massif, 55th Geological Congress of Turkey, Abstracts Book, 102-103.
• Genç Y., 2003. New observations on the metamorphic stratigraphy of the Kırşehir Massif, 56th Geological Congress of Turkey, Extended Abstracts Book, 55-56.
• Genç Y, Türkmen H, Coşkun E, Çamaşırcıoğlu A, Aydınlı I and Demiray B., 2003. Çayağzı-Terziali (Kırşehir) gold mineralization: the first example of unconformity-related gold mineralisations in the Kırşehir Metamorphic Massif, 56th Geological Congress of Turkey, Extended Abstracts Book, 120-121.
• Genç Y, Vennemann TW and Satir M., 2003a. Carbon, oxygen and hydrogen isotope evidence for the origin of the sediment hosted Pöhrenk (Çiçekdağı-Kırşehir-central Anatolia) fluorite deposit, Turkey. In: Eliopoulos et al (eds), Mineral Exploration and Sustainable Development, Proceedings vol. 2: 871-874. 7th Biennial SGA Meeting, Athens, Greece, 24-28 August 2003.
• Genç Y., 2004. Savcılı migmatite-dome hosted gold-quartz veins in Kırşehir Metamorphic Core Complex (KMCC), central Anatolia, Turkey. In: Chatzipetros AA and Pavlides SB (eds.), Proceedings vol. 3: 1394-1397. 5th International Symposium on Eastern Mediterranean Geology, Thessaloniki, Greece, 14-20 April 2004.
• Genç Y and Yürür T., 2004. The Kırşehir detachment faulting and a new interpretation of the “Savcılı Thrust Zone” in central Anatolia, Turkey. In: Chatzipetros AA and Pavlides SB (eds.) Proceedings, vol. 1: 73-76. 5th International Symposium on Eastern Mediterranean Geology, Thessaloniki, Greece, 14-20 April 2004.
• Genç Y and Yürür T., 2010. Coeval extension and compression in Late Mesozoic–Recent thin–skinned extensional tectonics in central Anatolia, Turkey. Journal of Structural Geology 32 (5), 623–640.
• Geven A., 1992. Mineralogy, Petrography and Geochemistry of Cefalıkdağ Plutonic Rocks (Kaman region-Central Anatolia). Ph.D. thesis, Middle East Technical University, 165 pp. (unpublished).
• Gleeson SA, Yardley BWD, Munz IA and Boyle AJ., 2003. Infiltration of basinal fluids into high-grade basement, south Norway: sources and behaviour of waters and brines, Geofluids 3: 33-48.
• Goldfarb RJ, Phillips GN and Nokleberg WJ ., 1998. Tectonic setting of synorogenic gold deposits of the Pacific Rim, Ore Geology Reviews 13: 185-218.
• Göncüoğlu MC., 1986. Geochronological age data from the southern part of the central Anatolia Massif. Bulletin of Mineral Research and Exploration Institute of Turkey 105/106: 111-124 (in Turkish).
• Göncüoğlu MC, Toprak V, Kuşçu İ, Erler A and Olgun E ., 1991. The geology of the western part of the central Anatolia Massif, chapter 1: Southern part. National Oil and Gas Company of Turkey, Report No: 2909, 140pp (in Turkish with English abstract).
• Groves DI., 1993. The crustal continuum model for late-Archean lode gold deposits of the Yilgarn Block, Western Australia. Mineralium Deposita 28: 366-374.
• Groves DI, Goldfarb RJ, Gebre-Mariam M, Hagemann SG and Robert F., 1998. Orogenic gold deposits: A proposed classification in the context of their crustal distribution and relationship to other gold deposit types. Ore Geology Reviews 13: 7-27.
• Groves DI, Goldfarb RJ, Robert F and Hart CJR., 2003. Gold deposits in metamorphic belts: overview of current understanding, outstanding problems, future research, and exploration significance. Economic Geology 98: 1-29.
• Guha J and Kanwar R., 1987. Vug brines – fluid inclusions: a key to understanding of secondary gold enrichment processes and the evolution of deep brines in the Canadian Shield. In: Fritz P and Frape SK (eds) Saline Water and Gases in the Crystalline Rocks. Geological Association of Canada Special Paper 33: 95-101.
• Haynes DW., 2000. Iron Oxide Copper (-Gold) Deposits: Their Position in the Ore Deposit Spectrum and Modes of Origin. In: Porter TM (ed.) Hydrothermal Iron Oxide Copper-Gold and Related Deposits: A Global Perspective, Australian Mineral Foundation, Adelaide, 71-90.
• Hagemann SG and Ridley JR., 1993. Hydrothermal fluids in epi- and katazonal crustal levels in the Archean: implications for P-T-X-t evolution of lode-gold mineralisation. In: Williams PR and Haldane JA (eds) Kalgoorlie ’93: An International Conference on Crustal Evolution, Metallogeny and Exploration of the Eastern Goldfields: Australian Geological Survey Organisation, Record 1993/54: 123-130.
• Hitzman MW., 2000. Iron oxide-Cu-Au deposits: what, where, when, and why. In: Porter TM (ed.) Hydrothermal Iron Oxide Copper-Gold and Related Deposits: A Global Perspective. Australian Mineral Foundation, Adelaide: 9-25 ICS., 2004. International Commission on Stratigraphy: 2004: International Stratigraphic Chart.
• Ilbeyli N, Pearce JA, Thirlwall MF and Mitchell JG., 2004. Petrogenesis of collision-related plutonics in central Anatolia, Turkey. Lithos 72(3-4): 163-182.
• Kadıoğlu YK., Dilek Y., Güleç N. and Foland KA., 2003. Tectonomagmatic evolution of bimodal plutons in the Central Anatolian Crystalline Complex, Turkey. Journal of Geology 111: 671-690.
• Ketin I., 1955) On the geology of Yozgat region and the tectonic features of the Central Anatolian Massif (Kırşehir Crystallines). Bulletin of the Geological Society of Turkey VI (1): 1-20 (in Turkish with English abstract).
• Ketin I., 1966. Tectonic units of Anatolia (Asia Minor). Bulletin of the Mineral Research and Exploration Institute of Turkey 66 (foreign edition): 23-34.
• McCuaig TC. and Kerric R., 1994. P-T-t deformation-fluid characteristics of lode gold deposits: Evidence from alteration systematics. In: Lentz DR (ed.) Alteration and Alteration Processes associated with Ore-Forming Systems. Geological Association of Canada, Short Course Notes 11: 339-379.
• Mehnert KR., 1968. Migmatites and the origin of granitic rocks. Elsevier, New York, 393pp.
• Möller P, Weise SM, Althaus E, Bach W, Behr HJ, Borchardt R, Bräuer K, Drescher J, Erzinger J, Faber E, Hansen BT, Horn EE, Heunges E, Kämpf H, Kessels W, Kirsten T, Landwehr D, Lodemann M, Machon L, Pekdeğer A, Pielow H-U, Reutel C, Simon K, Walther J, Winlich FH, Zimmer M., 1997. Paleofluids and recent fluids in the upper continental crust: results from the German Continental Deep Drilling Program (KTB). Journal of Geophysical Research 102, B18233-18254.
• MTA., 2002. Geological maps of Turkey, 1/500,000 scale, Ankara sheet, MTA (General Directorate of Mineral Research and Exploration), Ankara.
• Mullis J, Dubessy J, Poty B, and O’Neil J ., 1994. Fluid regimes during late stages of continental collision: Physical, chemical, and stable isotope measurements of fluid inclusions in fissure quartz from a geotraverse through the Central Alps, Switzerland. Geochemica et Cosmochimica Acta 58/10, 2239-2267.
• Munz IA, Yardley BWD, Banks DA and Wayne D., 1995. Deep penetration of sedimentary fluids in basement rocks from southern Norway: evidence from hydrocarbon and brine inclusions in quarz veins. Geochimica et Cosmochimica Acta 59(2): 239-254.
• Özcan A. and Çağatay MN., 1989. Tungsten exploration in semiarid environment: Central Anatolian Massif, Turkey. Journal of Geochemical Exploration 31, 185-199.
• Özer S. and Göncüoğlu MC., 1983. Interesting mineral parageneses from the eastern part (Akdağmadeni-Yıldızeli) of the Central Anatolian Massif. Bulletin of Mineral Research and Exploration Institute of Turkey 95/96: 173-174 (in Turkish).
• Pehlivan AN. and Alpan T., 1986. The preliminary report on gold, tin and heavy mineral explorations in Niğde Massif. MTA report, Ankara (in Turkish).
• Pettke T., Diamond LW. and Villa IM., 1999. Mesothermal gold veins and metamorphic devolatilization in the NW Alps: the temporal link. Geology 27: 641-644.
• Pettke T., Diamond LW. and Kramers JD., 2000. Mesothermal gold lodes in the north-western Alps: a review of genetic constraints from radiogenic isotopes. Eur. J. Mineral. 12: 213-230.
• Pollak A., 1958. Über einige geologische Beobachtungen im zentral-anatolischen Massiv. Notizbl. Hess. Landesamt Bodenforschung 87: 239-245.
• Pollard PJ., 2000. Evidence of a magmatic fluid and metal source for Fe-oxide Cu-Au mineralization. In: Porter TM (ed.) Hydrothermal Iron Oxide Copper-Gold and Related Deposits: a Global Perspective. Australian Mineral Foundation, Adelaide: 27-41
• Pollard PJ., 2001. Sodic (-calcic) alteration in Fe-oxide-Cu-Au districts: an origin via unmixing of magmatic H2O-CO2-NaCl + CaCl2-KCl fluids. Mineralium Deposita 36: 93-100.
• Robert ., 1995) Gold-quartz veins in metamorphic terranes and their bearing on the role of fluids in faulting. Journal of Geophysical Research 100-B7: 12861-12879.
• Seymen I., 1981. Stratigraphy and metamorphism of the Kırşehir Massif around Kaman (Kırşehir-Turkey). Geological Society of Turkey Bulletin 24(2): 101-108 (in Turkish with English abstract).
• Seymen., 1982. Geology of Kırşehir Massif around Kaman. ITU Min.Fac. Istanbul, 164pp. (unpublished Thesis, in Turkish with English abstract).
• Seymen I., 1984. Geological evolution of the metamorphic rocks in the Kırşehir Massif. Türkiye Jeoloji Kurumu, Ketin Symposium Book, 133-148 (in Turkish with English abstract).
• Seymen I., 2000. Geology of the Kırşehir Massif between Savcılıebeyit (Kaman) and Yeşilli (Kırşehir) villages. Cumhuriyetin 75. Yıldönümü Yerbilimleri ve Madencilik Kongresi, Bildiriler Kitabı I, MTA-Ankara, 67-91 (in Turkish with English abstract).
• Sezerer-Kuru G. and Genç Y., 2003. Fluid inclusion studies in the gold bearing quartz veins in Savcılıebeyit (Kaman-Kırşehir) Region. 56th Geological Congress of Turkey, Extended Abstract Book, pp 92.
• Smith MP., Savary V., Yardley BWD., Valley JW., Royer JJ. and Dubois M ., 1998. The evolution of the deep flow regime at Soultz-sous-Forêts, Rhine Graben, Eastern France: evidence from a composite quartz vein. Journal of Geophysical Research 103, 27223-27237.
• Stober I. and Bucher K ., 1999. Deep groundwater in the crystalline basement of the Black Forest region. Applied Geochemistry 14, 237-254.
• Stüwe K ., 1998. Tectonic constraints on the timing relationships of metamorphism, fluid production and gold-bearing quartz vein emplacement. Ore Geology Reviews 13: 219-228.
• Tolluoğlu Ü., 1986. Petrographical and petrotectonic investigations in the southwestern part of the Central Anatolia Massif, Kırşehir region. Ph.D. thesis, Hacettepe University, Ankara. 237pp. (in Turkish with English abstract, unpublished).
• Tolluoğlu Ü. and Erkan Y., 1989. Regional progressive metamorphism in the central Anatolian crystalline basement, NW Kırşehir Massif, Turkey. METU Journal of Pure and Applied Sciences 22(3): 19-41.
• Tülümen E., 1980. The petrographic and metallogenic investigation of the Akdağmadeni region. Ph.D thesis, Karadeniz Technical University, 157pp (in Turkish with English abstract, unpublished).
• Türkmen H., Demiray B., Karabalık N., Konya S., Yüce N., Çamaşırcıoğlu A. and Bilgin R., 2000. Geological map of the Savcılıebeyit gold mineralisation (unpublished data), MTA, Ankara.
• Whitney DL. and Dilek Y., 1998. Metamorphism during Alpine crustal thickening and extension in central Anatolia, Turkey: the Niğde metamorphic core complex. Journal of Petrology 39(70): 1385-1403.
• Whitney DL., Teyssier C., Dilek Y. and Fayon AK., 2001. Metamorphism of the Central Anatolian Crystalline complex, Turkey: influence of orogen-normal collision vs. wrench-dominated tectonics on P-T-t paths. Journal of Metamorphic Geology 19: 411-432.
• Whitney DL., Teyssier C., Fayon AK., Hamilton MA. and Heizler M., 2003. Tectonic controls on metamorphism, partial melting, and intrusion: timing and duration of regional metamorphism and magmatism in the Niğde Massif, Turkey. Tectonophysics 376: 37-60.
• Yardley BWD. and Bottrell SH., 1992. Silica mobility and fluid movement during metamorphism of the Connemara schists, Ireland. Journal of Metamorphic Geology 10: 453-464.