Fluid-Inclusion and Stable-Isotope Characteristics of the Inler Yaylasi Lead-Zinc Deposits, Northern Turkey (original) (raw)
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2007
The Eastern Black Sea Region of Turkey contains over 400 massive (Kuroko-type) and vein-type Cu-Pb-Zn deposits. The Inler Yaylasi lead-zinc deposits are typical examples of the vein type and have been economically mined for 15 years. Three ore veins were identified along E-W-trending fault zones, hosted by extensively altered, Upper Cretaceous volcano-sedimentary rocks. A Tertiary granitoid intrusion occurs near the area of mineralization. The ore veins contain sphalerite, galena, and minor amounts of pyrite, chalcopyrite, fahlore, chalcocite, and covellite as ore minerals, with quartz and calcite as gangue minerals. Fluid-inclusion studies show that the salt composition, salinity, and temperature of the hydrothermal fluids changed during various mineralization episodes. The temperature and salinity of the fluid were high (average temperature of 312.9°C and average salinity of 7.0% NaCl equiv.), and the fluid contained CaCl 2 , MgCl 2 , and NaCl during an early episode of mineralization characterized by quartz crystallization. During the sulfide crystallization, temperature and salinity were lower (average temperature of 272.0°C and average salinity of 4.0% NaCl equiv.), and the salts were mainly MgCl 2 , NaCl, and FeCl 2. During subsequent mineralization episodes, temperature and salinity were still lower (average temperature 138.5 °C and average salinity 2.6% NaCl equiv.), and the salt content was dominated by NaCl, Na 2 CO 3 , NaHCO 3 , Na 2 SO 4 , and KCl. Oxygen-and hydrogen-isotope results (δ 18 O; +4.2 to +6.7 ‰ VSMOW and δ D;-83.0 to-59.0 ‰ VSMOW) suggest that magmatic water dominated the ore fluid. It is possible, however, that small amounts of meteoric water and/or formation water of meteoric origin were also involved. This isotopic composition may also be the result of interaction of meteoric water with magmatic rocks, as has been suggested for other deposits in the eastern Black Sea region. The decrease in temperature and salinity of the fluid and the increase in δ 18 O values of the water from 1725 to 1803 m levels also supports the hypothesis that these deposits formed where upwelling hot fluids met cold surfical fluids.
Hydrothermal vein-type deposits of the Kabadüz region (Ordu, NE-Turkey) are located in Upper Cretaceous andesitic–basaltic rocks and were formed in fault zones along NW–SE direction lines, with thicknesses varying between a few centimetres up to 2 m. The primary mineral paragenesis of the many different ore veins consists of pyrite, chalcopyrite, sphalerite, galena and tetrahedrite–tennantite, with quartz and lesser amounts of calcite and barite as gangue minerals. Electron microprobe analyses indicate that the sphalerite and tetrahedrite– tennantite have low Fe contents, with values less than 3.37 wt.% and 1.56 wt.%, respectively. The very low Ni and Co contents of the pyrites (b 0.04 wt.%) and the Zn/Cd ratio of the sphalerite (~ avg. 100) indicate that the hydrothermal solutions were related to felsic magmatic activity. The homogenisation temperatures and calculated salinity data vary between 180–436 °C and 0.4–14.7 NaCl % eq., respectively. A well-defined negative correlation between the Th and the salinity data suggests that meteoric water was involved in the hydrothermal solutions. Based on the measured first melting temperatures, CaCl2, MgCl2, NaCl and KCl were dominant in the fluid inclusions. The δ34S compositions of the pyrite, chalcopyrite, sphalerite, and galena mineral separates of the investigated ore veins were measured at between 2.14 and −1.47‰, and the oxygen and hydrogen isotope compositions varied between 7.8–8.5‰and−40−57‰, respectively. Based on the sulphur, oxygen and hydrogen isotope compositions, magmatic sourceswere confirmed for the hydrothermal solutions. Taking into account all of the above data and the granitic intrusions around the area, we concluded that younger granitic intrusions were responsible for the ore mineralisation around the Kabadüz region.
International Geology Review, 2009
The Akgüney copper–lead–zinc deposit (Ordu Province) is actively mined in the eastern Black Sea Region of Turkey. This deposit consists of ore‐bearing veins emplaced along fault zones and hosted by slightly altered Upper Cretaceous andesites. Seven ore veins, D‐1 to D‐7, have been identified. These veins strike N 70–80°W with a dip of 50–60°NE, except for D7 which strikes E–W with a dip of 25°S. The ore‐bearing quartz vein outcrops are slightly limonitized and hematitized. Two different ore associations are distinguished within the D‐1 and D‐2 veins. The first contains only pyrite, whereas the second consists of coarse‐grained sulphides such as chalcopyrite, galena, sphalerite, tetrahedrite, and secondary limonite veinlets in addition to pyrite. Quartz and calcite are the gangue minerals. The mineral paragenesis has been identified as: pyrite→galena→chalcopyrite (I)→sphalerite→chalcopyrite (II)→(tetrahedrite ?)→quartz→calcite. Fluid inclusion data indicate that the ore‐forming fluids contained significant concentrations of divalent cations in addition to NaCl. The salinity of the fluids lies in the range 14–24% (ave. = 19.0) NaCl equivalent; liquid homogenization temperatures range from 276 to 349°C (ave. = 307°C) and decrease to 211°C through the later stages of mineralization. Oxygen and hydrogen isotope data are consistent with the mineralizing fluid being of meteoric origin, with modification of the oxygen isotope composition by exchange with the volcanic host rocks. However, low δD values suggest a magmatic water component in some samples. The combination of fluid inclusion and stable isotope data suggest that the Akgüney Cu–Pb–Zn vein‐type deposits were formed by the leaching of metals and sulphur from the surrounding volcano‐sedimentary rocks by deep‐circulating meteoric water.
Bulletin Of The Mineral Research and Exploration, 2016
The Kocadal base and precious metal mineralizations are located in the southwest of Gümüşhane province of the eastern Pontide orogenic belt. In the vicinity of the Kocadal mineralization, Gümüşhane granite, lithologies of the Hamurkesen, Berdiga, and Mescitli formations, dacite porphyry and andesite porphyry are present with abundant alluvium. Based on geological, mineralogical, and geochemical features, three mineralization styles have been recognized at the Kocadal area: (i) Mineralizations around Batarya tepe include (ia) Zn mineralization within the conglomerates and sandstones of the Hamurkesen formation and (ib) Zn-Pb-Ag-(Au) mineralization associated with dacite prophyry, (ii) Au mineralization, which occurs to the southwestern of Batarya tepe, and (iii) Cu mineralizations related to quartz veins and veinlets at Gözelerin Dere. Mineralized gravels within the conglomerates contains mainly sphalerite and pyrite, whereas hydrothermal mineralizations associated with porphyritic dacite comprise pyrite and sphalerite, with minor galena, chalcopyrite, pyrrhotite, arsenopyrite, marcasite, fahlerz, pyrargyrite, and proustite. Alteration patterns of hydrothermal mineralization in the field, from older to younger, are classified as: (i) tremolite-actinolite±garnet, (ii) quartz-sericite-chlorite, and (iii) carbonatequartz. Mineralized gravels within the conglomerates contains mainly sphalerite and pyrite, whereas pyrite, chalcopyrite, and galena are common in quartz veins at Gözelerin Dere. Geostatistical studies based on the results of geochemical analysis of core samples reveal the presence of the distinct element associations for the different styles of mineralizations. Table 2-In whole of the drill core samples, elements showing meaningful correlations with each other. SouthWest of Batarya Hill (
Ore Geology Reviews, 2017
Upper Cretaceous volcano-sedimentary sequences of the Eastern Pontide orogenic belt, NE Turkey, are host to significant VMS mineralization, including near Tunca. The initial stages of felsic volcanism within the mineralized area are marked by the eruption of dacitic lavas and breccias of the Kızılkaya Formation. This was accompanied by the emplacement of domelike hematitic dacites. Autobrecciated and volcaniclastic rocks, both in situ and resedimented, were likely generated from extrusive portions of these dacite bodies. Basaltic volcanism is marked by the eruption of the lava flows and pillow lavas of the Çağlayan Formation. Hiatuses in basaltic activity are marked by thin horizons of volcaniclastics and mudstones. The uppermost felsic volcanic units were accompanied by resedimentation of autoclastic facies from previous volcanism and represent the latest phase of Upper Cretaceous volcanism in the area. The semimassive sulfide mineralization is associated with a late stage of the initial felsic volcanism. U-Pb LA-ICP-MS zircon dating of a dacitic tuff breccia yielded an age of 88.1 ± 1.2 Ma (Coniacian-Upper Cretaceous), which is interpreted to be the age of the sulfide occurrences. A concentric zoned alteration pattern is observed in the footwall rocks. The alteration pattern is considered to have formed by lateral migration of hydrothermal fluids which had ascended along the discharge conduit. Fluid inclusion data indicate precipitation or mobilization processes within a relatively narrow temperature range of 152° to 255°C (avg. 200°C). The low-salinity fluids in the fluid inclusions, less than 5.9 wt.% NaCl equivalent, are consistent with typical modified seawater-dominant hydrothermal vent fluids. Sulfur isotope analysis of the Tunca sulfides yields a narrow range of 1.5 to 4.1 per mil. These δ 34 S values are also typical of many VMS deposits. Most of the recorded δ 18 O values (+7.1 to +14.0 per mil) are greater than 9 per mil. The most intensely hydrothermally altered rocks tend to have lower δ 18 O values relative to the less altered rocks. Collectively, the geologic relationships, mineralization style, and the lack of seafloor ore facies suggest that mineralization is principally of sub-seafloor origin. The most geologically reasonable interpretation of the genesis of the Tunca mineralization is the continuous interaction between the host rocks and seawater-derived fluids, without significant involvement of a magmatic fluid.
Central European Journal of Geosciences, 2013
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 ...
International Geology …, 2008
The Arapuçandere Pb-Zn-Cu ores are typical examples of vein-type lead-zinc deposits in the Biga Peninsula. Permian-Triassic metamorphic, Triassic metaclastic and metabasic rocks, Oligocene-Miocene granitoids, Miocene volcanic rocks, and Quaternary terrestrial sediments crop out in the study area. The veins occupy fault zones in Triassic metasandstone (meta-arkose and subarkose) and metadiabase, and contain galena, sphalerite, chalcopyrite, pyrite, marcasite, covellite and specular hematite as ore minerals, with quartz, calcite, and barite as gangue minerals. Based on macro-and micro-petrographic investigations, sulfide minerals formed in the earliest stage of mineralization, and were followed by quartz and calcite crystallization. Fluid inclusion studies showed that salinity (avg. 18.3%) was low, but that temperature was relatively high (avg. 301.4°C) during stages of sulfide precipitation. In contrast, the salinity (avg. 27.1% NaCl equiv.) increased and the temperature (avg. 240.2°C) decreased during crystallization of the quartz. Finally, the salinity and temperature of the fluid gradually declined through the later episode of mineralization when the primary and secondary inclusions in calcite formed. Isotopic compositions of the aqueous fluid (δ 18 O = -7.5 to -1.7‰, and δD = -90 to -55‰) indicate the presence of meteoric water modified slightly by fluid-rock interaction.
Geology of Ore Deposits, 2008
The Karalar galena-barite deposits are typical examples of the carbonate-hosted barite-galena deposits widely occurring in the Central Tauride Belt. These deposits are located in Permian limestones as ore veins along fault zones that are discordant to the bedding planes and as thin veinlets within hardly brecciated bottom zones of Permian limestones. The ore deposits contain mainly barite and galena and small amounts of sphalerite, pyrite, fahlore, limonite, quartz, and calcite. Barites occur during the earlier episode of mineralization and were mylonitized before the formation of galena. Galena and other minerals occur epigenetically with barite along porous zones between brecciated barite crystals and are especially abundant in the hardly mylonitized zones. Fluid inclusion studies indicate that the ore deposits of the area were developed by hydrothermal fluids with following characteristics: they contained NaCl, CaCl2, and MgCl2; the salinity of the fluids was relatively high and their temperature was low during the crystallization of barites in the earlier episode of mineralization; and the salinity of the fluids decreased and their temperature increased during the crystallization of sulfide minerals through the later episode of mineralization. δ18O and the δD results indicate that the water in the mineralizing fluid was of meteoric origin. The deposits were formed by deep meteoric water circulating through marine sediments. Shallow circulating and slightly warmed fluids dissolved Ba and sulfate from marine sediments of the basement and transported them to the mineralization environment during the early episode, while deep circulating and more heated fluids dissolved Pb, Zn, and other elements from the basement and reached the environment during the later episode of mineralization.
Engineering Sciences, 2016
Sh. Abullayeva, V. Baba-zadeh, S and M Kekeliya, N.A. Imamverdiyev N., A. Romanko. Abstract. Genetic peculiarities, gold-containing volcanogenic deposits of the non-ferrous metals of the paleoisland-arc structures of the Lesser Caucasus and East Pontids according to gas-fluid inclusions data and isotopic investigations Abstract: The geological settings of deposits' exploration in Turkey, Azerbaijan, Armenia and Georgia have been determined in the article. Most of them can be related to the Kuroko type and they are differed by ore accumulation nature: the copper-zinc deposits formed apparently in the conditions of the deep sea basin are known in Turkey but to the east-we have only epigenetic deposits examples. Moreover Madneuli deposit is developed in Bolnisi region. It is an example of polyformational deposit and therefore is unique. The barite deposits, barite-polymetallic veins, gold-bearing secondary quartzites and large-scale stockworks of copper ores are concentrated in a confined space (known as biclinal structure on large volcano slope). Gadabey and Alaverdi ore districts are of interest because there are copper, copper-zinc and barite-sulphide ores in the Jurassic volcanic depressions but copper-porphyry deposits-Garadag and Tekhut are known in upstanding wedge-shaped blocks limiting volcanic depressions. All deposits of Gadabey and Alaverdi ore districts including copper-porphyry are commercially important. The solutions from which the sulphides deposited were similar to seawater according to salinity and were weakly acidic; copper-containing sulphides were formed at maximum 410-390 0 C temperatures but barite-sulphide ones-at ~ 280 0 C. In all probability the fluid pressure didn't exceed 200 bar in the epigenetic deposits. The stable accumulation of hydrothermal-sedimentary deposits occurred at the bottom of the sea which depth reached 2-3 km. Apparently the fluid boiling didn't occur and mineral zonation in deposits being similar to modern " ore hills " can be explained by redistribution of the ore-forming components as a result of " hills " destruction, their diffusion from the lower levels up to the upper ones in the process of ores " washout " by ore-bearing fluids.