Boron isotope ratios and origin of boron in thermal fluids of some geothermal areas in Western Anatolia Murat TOKCAER Journal of the Faculty of Engineering and Architecture of Gazi University, 2023 Batı Anadolu’nun tektonik olarak aktif graben bölgeleri, birçok jeotermal aktivite ve jeotermal sularda oldukça yüksek bor zenginleşmesi ile karakterizedir. Köken konusunda farklı kaynakları belirlemek için bor izotop jeokimyasının jeolojik çalışmalarda yaygın olarak kullanımı oldukça yenidir. Borun jeotermal akışkanlardaki kökenini belirleyebilmek amacıyla, örneklenen termal suların B izotop oranları, suların kimyasal analiz sonuçları ve bölgelerin jeolojileri birlikte değerlendirilmiştir. İncelenen termal suların genellikle Na-HCO3, Ca, Na- HCO3, Ca-HCO3,Cl ve Na-Cl tipinde oldukları saptanmıştır. Yüksek sıcaklığa sahip, soğuk sular ile seyrelmenin az olduğu bölgelerde B konsantrasyonları oldukça yüksek (B=52,1mg/l; Salihli), B izotop oranları ise litolojik farklılıklardan dolayı geniş bir aralıkta çıkmıştır (δ11B=-7,73‰ / +10,83‰; n=15). Tüm sularda sıcaklık ile çözülü iyonlar arasında ve benzer şekilde B - Cl ve B-elektriksel iletkenlikleri arasında pozitif korelasyon saptanmıştır. Ayrıca termal sulardaki B izotop oranları suların etkileşimde oldukları kayaçların B izotop oranları ile uyumlu çıkmış olması borun kökeni konusunda su-kaya etkileşimini destekler. Na-Cl tipindeki termal suların yüksek pozitif δ11B değerleri ise diğer kimyasal verilerin de desteklediği gibi denizel karışım sonucudur.
Petrology, geochemistry, and evolution of the iron skarns along the northern contact of the Eǧrigöz Plutonic Complex, Western Anatolia, Turkey TOLGA OYMAN, İSMET ÖZGENÇ, MURAT TOKCAER, MEHMET AKBULUT Turkish Journal of Earth Sciences, 2013 The Çatak and Küreci skarn districts are located approximately 10 km NW of Emet (Kütahya) in Western Turkey. The skarn and associated ore formations mainly occur at the contact between intrusive rocks of the Eğrigöz Plutonic Complex (EPC) and calcareous pelitic schists with limestone lenses of the Sarıcasu Formation and meta-carbonate rocks of the Arıkaya Formation. The major, trace, and rare earth element analysis of the igneous rocks indicate that they are high level, subalkaline, calc-alkaline, peraluminous to metaluminous I-type intrusions, generated in a continental arc setting. Three distinct skarn-type mineralization, differing in their host rocks and distance from the intrusive body, were chosen to establish the ore-forming conditions in different episodes of skarn formation. The Küreci iron mineralization is hosted in a skarn zone with well-developed zoning from unaltered granodiorite and endoskarn, andradite-diopside exoskarn, to diopside-wollastonite exoskarn towards a marble reaction front. In Sakari, the iron mineralization and associated skarn have formed due to successive fracturing and infiltration processes. From early contact metamorphic rocks to late prograde skarn at the Sakari prospect, the composition of clinopyroxene ranges from (Di_{50-70} Hd_{28-53} Jo_{1-2}) to (Di_{19-73} Hd_{26-77} Jo_{2-6}) and the composition of garnet ranges from (Ad_{95-99} Gr_{1-5}) to (Ad_{40-61} Gr_{36-58}), respectively. The presence of anisotropic grossular garnet with high Fe^{2+}/Fe^{3+} in crosscutting pyrrhotite-pyrite-bearing veinlets coupled with hedenbergitic pyroxene (Mg-poor clinopyroxene with higher Fe^{2+}/Fe^{3+}) is consistent with reducing conditions during the later stage of prograde skarn alteration. The Çatak iron skarn is characteristic, with its high sulphide content due to the presence of pyrrhotite, pyrite, and arsenopyrite, and low proportion of garnet to pyroxene. The sulphur isotope (\delta^{34}S) compositions in the pyrrhotite-dominant skarn zones range between +0.84 to -2.23&permil. We interpret the bulk of the sulphur in the system as of igneous derivation and there has not been any significant sulphur contribution from a crustal source. Fluid inclusion measurements conducted on skarn minerals of the proximal zone and distal zone+vein skarn revealed high homogenization temperatures (371 to >600°C) and varying salinity values (10.5 to >70 wt% NaCl). The fluid inclusion data indicate that there are at least three fluids associated with the genesis of the proximal skarn where the high garnet/pyroxene ratios are found. Fluid inclusions that represent the early stages both in garnet and pyroxene plot in 'Primary Magmatic Fluid' and 'Metamorphic Fluids' fields. A magmatic fluid, presumably located at deeper parts of the system, mixed with a metamorphic fluid during its
Volcanic rocks from Foça-Karaburun and Ayvalık-Lesvos grabens (Western Anatolia) and their petrogenic-geodynamic significance SAMUELE AGOSTINI, MURAT TOKÇAER, MEHMET YILMAZ SAVAŞÇIN Turkish Journal of Earth Sciences, 2010 The Foça-Karaburun and Ayvalık-Lesvos grabens (western coast of Anatolia, Turkey) are two important NW-SE-trending extensional areas generated in response to the Early Miocene-Holocene extension of the Western Anatolian region, related to the opening of the "unconventional" back-arc basin of the Aegean Sea. The abundance of geo-structural evidence and the occurrence of volcanic rocks representing all the stages of the Aegean-Western Anatolia volcanism render the Foça-Karaburun and Ayvalık-Lesvos Grabens key localities to exemplify the petrogenetic and geodynamic evolution of the area. In this context, the Foça-Karaburun and Ayvalık-Lesvos grabens, possibly formerly a single graben, formed along an original NE-SW-trending extension, later dissected by E-W-trending transtensional faults, are investigated to constrain the petrogenetic and geodynamic evolution of the whole Aegean region. Calc-alkaline and shoshonitic volcanic rocks with scattered ultrapotassic-shoshonitic or lamproitic lavas and dykes represent the orogenic phase of the magmatic activity, while the younger K- and Na-rich alkaline basaltic rocks are the result of later magmatism characterized by an intraplate geochemical signature reflecting progressively decreasing subduction rates. While the tectonic lineaments and the structures of the study area allow the reconstruction of the tectonic evolution of Western Anatolia and Aegean Sea, the volcanic rocks from the different stages of Neogene volcanism within the two studied grabens and surrounding areas permit a precise record of the geochemical evolution of the magma sources.
Geotectonic setting and origin of the youngest Kula volcanics (western Anatolia), with a new emplacement model Turkish Journal of Earth Sciences, 2005
RECENT SCHOLAR PUBLICATIONS
Batı Anadolu’daki bazı jeotermal alanların termal akışkanlarında bor izotop oranları ve borun kökeni M Tokcaer Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi 38 (3), 1361-1374 , 2023 2023 Citations: 2
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Clay mineralogy and geochemistry of fossil and active hydrothermal alteration in the Hisaralan Geothermal Field (Sındırgı‐Balıkesir), western Turkey C Kocabaş, M Tokçaer, M Çolak Afyon Kocatepe Üniversitesi Fen Ve Mühendislik Bilimleri Dergisi 16 (1), 132-154 , 2016 2016 Citations: 4
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Volcanic rocks from Foça-Karaburun and Ayvalik-Lesvos grabens (western Anatolia) and their petrogenetic-geodynamic significance S Agostini, M Tokcaer, MY SAVAŞÇIN Turkish Journal of Earth Sciences 19 (2), 157-184 , 2010 2010 Citations: 40
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Geotectonic setting and origin of the youngest Kula volcanics (western Anatolia), with a new emplacement model M Tokçaer, S Agostini, MY Savaşçin Turkish Journal of Earth Sciences 14 (2), 143-166 , 2005 2005 Citations: 105
MOST CITED SCHOLAR PUBLICATIONS
Geotectonic setting and origin of the youngest Kula volcanics (western Anatolia), with a new emplacement model M Tokçaer, S Agostini, MY Savaşçin Turkish Journal of Earth Sciences 14 (2), 143-166 , 2005 2005 Citations: 105
Volcanic rocks from Foça-Karaburun and Ayvalik-Lesvos grabens (western Anatolia) and their petrogenetic-geodynamic significance S Agostini, M Tokcaer, MY SAVAŞÇIN Turkish Journal of Earth Sciences 19 (2), 157-184 , 2010 2010 Citations: 40
Petrography, mineral chemistry, fluid inclusion microthermometry and Re–Os geochronology of the Küre volcanogenic massive sulfide deposit (Central Pontides, Northern Turkey) M Akbulut, T Oyman, M Çiçek, D Selby, İ Özgenç, M Tokçaer Ore Geology Reviews 76, 1-18 , 2016 2016 Citations: 35
Petrology, geochemistry, and evolution of the iron skarns along the northern contact of the Eğrigöz Plutonic Complex, Western Anatolia, Turkey T Oyman, I Özgenç, M Tokcaer, M Akbulut Turkish Journal of Earth Sciences 22 (1), 61-97 , 2013 2013 Citations: 31
Clay mineralogy and geochemistry of fossil and active hydrothermal alteration in the Hisaralan Geothermal Field (Sındırgı‐Balıkesir), western Turkey C Kocabaş, M Tokçaer, M Çolak Afyon Kocatepe Üniversitesi Fen Ve Mühendislik Bilimleri Dergisi 16 (1), 132-154 , 2016 2016 Citations: 4
Batı Anadolu'daki Jeotermal Alanlar ve Jeodinamik Konulmları M Tokçaer, MY Savaşcın Geosound 48 (1), 159-178 , 2006 2006 Citations: 3
Batı Anadolu’daki bazı jeotermal alanların termal akışkanlarında bor izotop oranları ve borun kökeni M Tokcaer Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi 38 (3), 1361-1374 , 2023 2023 Citations: 2
