(Simav-Kütahya) Cu-Pb-Zn-(Ag) Mineralization, NW TURKEY
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Cent. Eur. J. Geosci. • 5(3) • 2013 • 435-449 DOI: 10.2478/s13533-012-0139-2 Central European Journal of Geosciences Fluid Inclusion and Sulfur Isotope Thermometry of the Inkaya (Simav-Kütahya) Cu-Pb-Zn-(Ag) Mineralization, NW TURKEY Research Article Yeșim Özen∗ and Fetullah Arik† Geological Engineering Department, Selçuk University, Konya, Turkey Received 14 May 2013; accepted 18 August 2013 Abstract: The Inkaya Cu-Pb-Zn-(Ag) mineralization, located about 20 km west of the Simav (Kütahya-Turkey), is situated in the northern part of the Menderes Massif Metamorphics. The mineralization is located along an E-W trending fault in the Cambrian Simav metamorphics consisting of quartz-muscovite schist, quartz-biotite schist, muscovite schist, biotite schist and the Arıkayası formation composed of marbles. Mineralized veins are 30-35 cm in width. The primary mineralization is represented by abundant galena, sphalerite, chalcopyrite, pyrite, fahlore and minor amounts of cerussite, anglesite, digenite, enargite, chalcocite, covellite, bornite, limonite, hematite and goethite with gangue quartz. Fluid inclusion studies on the quartz samples collected from the mineralized veins indicate that the temperature range of the fluids is 235°C to 340°C and the salinities are 0.7 to 4.49 wt. % NaCl equivalent. The wide range of homogenization temperatures indicates that two different fluid generations were trapped in quartz. Sulfur isotope studies of the sulfide minerals showed that all of the δ S values are between − : and 2.6 per mil. These values are a typical range for hydrothermal sulfide minerals that have sulfur derived from a magmatic 34 source. 2 1 Pyrite-galena and pyrite-chalcopyrite sulfur isotope fractionation is consistent with an approach to isotopic equi- librium, and calculated temperatures are 254.6 and 277.4°C for pyrite-galena and 274.7°C for pyrite-chalcopyrite. The microthermometric data and sulfur isotope thermometry indicate the existence of a hydrothermal fluid that circulated along the fault crossing the Simav metamorphics and Arıkayası formation. Fluid inclusion and sulfur isotope thermometry can be used in combination with ore petrographical and geological information to provide site-specific targets for meso-hypothermal metal concentrations. Keywords: Fluid inclusion • sulfur isotope thermometry • Inkaya Cu-Pb-Zn-(Ag) mineralization • Simav • meso-hypothermal © Versita sp. z o.o. 1. Introduction ∗ † E-mail: [email protected] E-mail: [email protected] The study area is located in Ahmetli (Simav-Kütahya) in the Western Anatolia Region which is one of Turkey’s most important metallic provinces. The area is located in the western part of the Anatolian tectonic belt, in the south- ern part of the İzmir-Ankara zone, and in the northern 435 Fluid Inclusion and Sulfur Isotope Thermometry of the Inkaya (Simav-Kütahya) Cu-Pb-Zn-(Ag) Mineralization, NW TURKEY part of the Menderes Massif and it is part of the Inner volcano-sedimentary sequence affected by HP/LT meta- West Anatolian of the Aegean Region. The Inkaya Cu- morphism, and this blueschist belt rests with a tectonic Pb-Zn-(Ag) mineralization is located about 20 km west of contact on the Afyon Zone at the south [12]. The Afyon the Simav (Kütahya-Turkey) (Fig. 1). The İnkaya Cu-Pb- zone was overthrusted by the Tavşanlı Zone and con- Zn-(Ag) mineralization is located along the E-W trending sists of shelf-type metasediments of Paleozoic-Mesozoic fault in the Simav metamorphics and the Arıkayası forma- age affected by low grade, regional, greenschist metamor- tion belonging to Menderes Massif Metamorfics, is vein phism [2, 4, 12, 13]. The Afyon Zone rests directly on the type mineralization (Fig. 2, Fig. 3). gneisses of the Menderes Massif [8]. [14] suggested that The WNW-ESE trending Simav Graben is located in the the Afyon zone of the Anatolides uncomformably overlies study area (Fig. 2). The Simav Graben was formed due to the Menderes Massif mentioned as a “core complex”. [15] the activation of the lateral component of the Simav Fault suggested that the north-south shortening of NW Turkey by N-S extension [1]. Several mineralizations (Arpaçukuru ceased at the end of the Oligocene and is replaced by N- Fe-Cu, Değirmenciler Sb, Gürkuyu Sb, Pınarbaşı Fe- S extension in the Lower Miocene. Thus, the extensional Cu-Pb-Zn mineralizations etc.), occur along the Simav regime formed the E-W extending graben systems in the Graben, and were formed in association with a tectono- region [16, 17] (Fig. 1 and Fig. 2). The Menderes Massif magmatic period. is interpreted as a “metamorphic core complex” formed on Geological studies on the metamorphic rocks of the region account of the listric faults, e.g. [14], [18–23] which consti- were carried out by [2–4]. [5, 6] studied the granitoids from tute the boundary of the graben. The development of the the petrogenetic point of view. [7] investigated the chem- magmatic activity in the western Anatolia is closely asso- ical composition and origin of volcanic rocks of Cenozoic ciated with the tectonic evolution of the region [12, 17, 24– age in the Simav region. [8] determined that mineraliza- 33]. As a result of the N-S compressional tectonic regime, tion is related to the faults of the Simav Graben. [9] stud- calc-alkaline volcanism closely associated with the gran- ied five mineralizations in the region that are products of itoids was developed in the region. syn-extensional magmatism related to the Menderes core The Simav Graben trending WNW-ESE is located in the complex. study area (Fig. 2). The alluvium is commonly shown in The present study was carried out in order to investigate the north part of the Simav Graben, whereas metamorphic the chemical-physical conditions and formation tempera- and plutonic rocks commonly crop out in the south part tures of the hydrothermal fluids and the mechanism of the (Fig. 2). The region is crossed by E-W trending faults İnkaya Cu-Pb-Zn-(Ag) mineralization using isotopic and which are nearly parallel to the Simav graben fault. The fluid inclusion data. In this study, fluid inclusion and sul- other fault system is a N-S trending set which cut the fur isotope thermometry data along with field observations former set of faults. and ore petrographical data were interpreted to constrain chemical and temperature conditions of the mineralizing Pre-Cambrian Menderes Massif Metamorphics (Kalkan fluids in the İnkaya Cu-Pb-Zn-(Ag) mineralization. The formation, Simav metamorphics, Sarıcasu formation, study of the İnkaya Cu-Pb-Zn-(Ag) mineralization and Arıkayası formation) form the basement in the region similar mineralizations along Simav Graben will poten- (Fig. 2). The massive is composed of a Precambrian tially be used to resolve problems regarding other similar “Gneiss core” and Paleozoic and Mesozoic “schist cover” mineralizations in the world. series [34–36]. According to [14] the “Gneiss core” con- 2. Geological settings stitutes the base of the lithological units within the stud- ied area. It consists of the Kalkan formation represented 2.1. Regional geological setting by migmatite and biotite-bearing gneiss. The “schist cover” includes the Simav metamorphics, the Sarıcasu for- mation and the Arıkayası formation from bottom to top. Simav metamorphics which constitute the basal unit of The study area is located at the Menderes Massif (meta- the schist cover begin with muscovite schist, and con- morphic core complex) in the Western Turkey. In Western tinue with muscovite-biotite schist comprising metamafic- Turkey, the Pontides and the Anatolide-Tauride Block are metaultramafic levels in the middle part of the unit [8]. separated by an ophiolitic belt, known as the Izmir-Ankara The Sarıcasu Formation consists of quartz, albite, chlorite, suture zone, thrust southwards onto the Anatolides and muscovite bearing schists representing lower grade meta- Taurides [10] (Fig. 1). The region is within the Anatolides morphic facies than the Simav Metamorphics [8]. Arıkayası tectonic unit [11]. The Anatolides consist of the Tavşanlı formation has both lateral and vertical gradation to the zone, the Afyon zone and the Menderes Massif from north Sarıcasu Formation, the unit is composed of marble [8]. to south, respectively. The Tavşanlı zone consists of a The Budağan limestone unconformably overlies the meta- 436 Y. Özen, F. Arik Figure 1. Geological and geotectonical maps of the Western Anatolia (after [45]). morphics, starting with a conglomerate level including replacement-type kaolinite and alunite deposits related abundant and quartz pebbles. Granitoids crop out in the to the Simav Graben [8, 9, 37–44]. The İnkaya Cu-Pb-Zn- northern part of the studied area to the north of the Simav (Ag) mineralization, the Arpaçukuru Fe-Cu mineralization Graben. According to modal compositions of the Eğrigöz and the Değirmenciler Sb mineralization are shown along Granitoid, the pluton comprises granite, monzogranite and 2.2.the Simav Local Graben geological in Figure setting2. - ˙Inkaya deposit granodiorite, and is calc-alkaline in compositon [8,9]. The Kızılbük formation, uncomformably overlying the grani- toids, is composed of the alternation of sandstone, clay- stone, marl and clayey limestone, all of dirty yellow to Mesothermal base-metal (Cu-Pb-Zn) veins are located in beige colours [8]. The Kızılbük formation grades to the the northern block of the Simav Graben [46–49]. These Civanadağ tuffs and is related to the Akdağ volcanites. mineralizations occur in the Eğrigöz granitoids and in the The Civanadağ tuffs consist of white and gray coloured gneisses of the Menderes Massif. The İnkaya Cu-Pb- tuffs with agglomerates in the upper levels. The tuffs are Zn-(Ag) mineralization is a similar Cu-Pb-Zn vein in the rhyolitic, andesitic and dasitic in composition. The Ak- southern block of the Simav Graben. The mineralization dağ volcanites consist of andesite, rhyolite, rhyodacite and occurs in the “schist cover” of the Menderes Massif as a dacite [8,9] (Fig.2).