Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2020Estimation of natural radionuclides’ concentration of the plutonic rocks in the Sakarya zone, Turkey using multivariate statistical methods
Yalcin, Fusun; Ilbeyli, Nurdane; Demirbilek, Mehmet; Yalcin, Mustafa Gurhan; Gunes, Alper; Kaygusuz, Abdullah; Ozmen, Suleyman Fatih
The study aimed to determine the natural radioactivity levels of226Ra,232Th, and40K by the Gamma-Ray spectrometry method, and radiological hazard parameters of the plutonic rocks in the Western and Central Sakarya Zone and to analyze the data using multivariate statistical methods. The average radiological values of samples were determined as40K (1295.3 Bq kg−1) >232Th (132.1 Bq kg−1) >226Ra (119.7 Bq kg−1). According to the skewness values of the distributions of the examined radionuclides,226Ra (2.1) and232Th (0.7) seemed to be positively right-skewed while40K (−0.2) had a negatively right-skewed histogram. On the other hand, the following kurtosis values were calculated for the distributions:226Ra (5.8 > 3),232Th (−0.7), and40K (−0.8). Kolmogorov–Smirnov and Shapiro–Wilk tests were applied to the data to test their normality. Therefore, Spearman’s correlation coefficient method was performed. The radionuclides of226Ra and232Th were found to have a positive correlation with radiological hazard parameters of the samples. 2 (two)-related factors identified, and the cumulative value was calculated to be 98.7% on the basis of the Scree Plot. According to the hierarchical cluster analysis, the samples that are grouped with those from Camlik region are prominent. The average radioactivity values of Camlik, Sogukpinar, Karacabey, and Sogut (except for232Th) regions were detected to be higher than the world averages while the value of40K was also found to be higher than the average values of various countries in the world.
- MakaleYalnız künye2020Eocene tonalite–granodiorite from the Havza (Samsun) area, northern Turkey: adakite-like melts of lithospheric mantle and crust generated in a post-collisional setting
Temizel, Irfan; Arslan, Mehmet; Yücel, Cem; Abdioğlu Yazar, Emel; Kaygusuz, Abdullah; Aslan, Zafer
Eocene intermediate to felsic plutons of different sizes and compositions are widespread in the Eastern Pontides Orogenic Belt in northern Turkey. Of these, the Taşlık Tepe pluton in the Havza (Samsun) area is fine-to-medium-grained, with granular, porphyritic, and micrographic textures, and include mafic microgranular enclaves (MMEs). LA-ICP-MS U-Pb zircon dating yielded emplacement ages of 42.9 (± 1.4) and 40.5 (± 1.3) Ma for the host granodioritic pluton and the dioritic MMEs, respectively. Petrochemically, the host pluton has I-type, high-K calc-alkaline, and metaluminous-to-slightly peraluminous features (A/CNK = 0.95–1.06). The host pluton also shows geochemical features of adakite-like rocks with high SiO2 (67–68 wt%) and Al2O3 (15.5–16.0 wt%) content and Ba/La (17–23), Sr/Y (40.7–61.6), and LaN/YbN (14.4–23.7) ratios and low Y (8.2–9.9 ppm) and YbN (3.1–4.4) contents. Whole-rock major and trace element variations suggest that fractional crystallisation played a significant role in the pluton evolution. The N-MORB normalised trace element patterns of the pluton are similar to those of MMEs with enrichment in large-ion lithophile elements, Th and Ce, and negative Nb and Ti anomalies. Chondrite-normalised rare earth element plots show moderate-to-highly enriched concave patterns (LaN/LuN = 14.2–21.6) with insignificant negative Eu anomalies (EuN/Eu* = 0.86–1.14), all of which imply hornblende fractionation during magmatic evolution. The pluton samples have 87Sr/86Sr ratios of 0.704767 to 0.704927, 143Nd/144Nd ratios of 0.512767–0.512774, εNd values of (+2.52)–(+2.65), and δ18O values of 7.9–9.7‰. The isotopic compositions of the host pluton and MMEs are similar to I-type granitoids derived from mantle sources. The MMEs show incomplete magma mixing/mingling, representing small bodies of mafic parental magma. Combined with regional studies, these new data suggest that the parental magma of the studied adakite-like pluton was generated from the lithospheric mantle and then modified by fractional crystallisation and assimilation in a post-collisional setting.
- MakaleYalnız künye2020Eocene I-type magmatism in the Eastern Pontides, NE Turkey: insights into magma genesis and magma-tectonic evolution from whole-rock geochemistry, geochronology and isotope systematics
Kaygusuz, Abdullah; Yücel, Cem; Arslan, Mehmet; Temizel, İrfan; Yi, Keewook; Jeong, Youn-Joong; Siebel, Wolfgang; Sipahi, Ferkan
The Eastern Pontides orogenic belt in NE Turkey hosts numerous I-type plutons of Eocene epoch. Here, we report new U–Pb SHRIMP zircon ages and in situ zircon Lu-Hf isotopes along with bulk-rock geochemical and Sr-Nd-Pb-O isotope data from the Kemerlikdağı, Aydıntepe and Pelitli plutons and mafic microgranular enclaves (MMEs) to constrain their parental melt source(s) and evolutionary processes. U-Pb SHRIMP zircon dating yielded crystallization ages between 45 and 44 Ma for the studied plutons and their MMEs. The plutons range from gabbro to granite and have I-type, medium to high-K calc-alkaline, and metaluminous to slightly peraluminous characteristics. On the primitive mantle-normalized multi-trace-element variations, the plutons and their MMEs are characterized by significant enrichment in LILE/HFSE. Chondrite-normalized REE patterns of the plutons and their MMEs are close to each other and show moderate enrichment with variable negative Eu anomalies. The studied plutons have fairly homogeneous isotope composition (87Sr/86Sr(i) = 0.70502 to 0.70560; εNd(i) = +0.9 to–1.4; δ18O = +5.0 to +8.7‰, εHf(i) =–2.2 to +13.5). The MMEs show medium to high-K calc-alkaline and metaluminous character. Although the isotope signatures of the MMEs (87Sr/86Sr(i) = 0.70508 to 0.70542; εNd(i) = +0.9 to −1.1; δ18O = +5.8 to +8.0, εHf(i) = +4.3 to +10.4) are very similar to those of the host rocks. Fractionation of plagioclase, amphibole, pyroxene and Fe-Ti oxides played an important role in the evolution of the plutons. The isotopic composition of the studied plutons and MMEs are similar to I-type plutons derived from mantle sources. The MMEs show incomplete magma mixing/mingling, representing small bodies of mafic parental magma. The parental magma(s) of the studied plutons were generated from the enriched lithospheric mantle and then modified by fractional crystallisation, and lesser assimilation and mixing/mingling in the crustal magma chambers.
- MakaleYalnız künye2019U-Pb geochronology, bulk-rock geochemistry and petrology of Late Cretaceous syenitic plutons in the Gölköy (Ordu) area (NE Turkey): Implications for magma generation in a continental arc extension triggered by slab roll-back
Temizel, İrfan; Arslan, Mehmet; Yücel, Cem; Yazar, Emel Abdioğlu; Kaygusuz, Abdullah; Aslan, Zafer
Late Cretaceous felsic plutons in the Eastern Pontides orogenic belt of Turkey are found in varying ages, sizes and compositions. The Late Cretaceous syenitic bodies, namely Direkli and Yeniköy Tepe plutons in the Ordu area, intruded into the Late Cretaceous volcanics and volcanoclastics, and compositionally consist of syenite and minor quartz-syenite with mainly granular and rarely porphyric, poikilitic and perthitic textures. The studied plutons contain K-feldspar, plagioclase, quartz, clinopyroxene, biotite and minor hornblende, and Fe-Ti oxide, apatite, and zircon. Mineral thermobarometer estimations imply that the syenitic plutons were crystallized in P-T conditions representing mid to shallow crustal levels. Petrochemically, these syenitic plutons show I-type, metaluminous-peraluminous transitional (A/CNK = 0.85–1.04) and shoshonitic features. LA-ICP-MS U-Pb zircon dating on the syenitic plutons yielded weighted mean ages of 78.5–72 Ma. Primitive mantle-normalized trace element patterns of the studied plutons are characterized by negative anomalies of Ba, Sr, Nb, Ta and Ti, and enrichment in Rb, Th, K, Ce and La. The chondrite-normalized rare earth element (REE) plots of the studied plutons show moderately enriched concave-shaped patterns (La N /Lu N = 10.3–10.7 for the Direkli pluton; La N /Lu N = 6.8–11.7 for the Yeniköy Tepe pluton) with negative Eu anomalies. The plutons have 87 Sr/ 86 Sr ratios (0.705368–0.706954), 143 Nd/ 144 Nd ratios (0.512600–0.512672), 206 Pb/ 204 Pb ratios (19.29–19.52) and 207 Pb/ 204 Pb ratios (15.65–15.67). The geochemical data, as well as regional geology, suggest that the Late Cretaceous syenitic plutons have formed in an extensional continental arc setting triggered by slab roll-back. The parental magma of syenitic plutons was derived from melts of lower crustal materials (metabasalt/metaandesite) and lithospheric mantle component.
- Proje2018Doğu Pontid Güney Zonu’ndaki (Bayburt) Tersiyer yaşlıintruzif kayaçların Petrokimyası, Jeokronolojisi ve İzotopSistematikleri
Çakmak, Gökhan; Temizel, İrfan; Kaygusuz, Abdullah; Arslan, Mehmet; Sipahi, Ferkan
Doğu Pontid güney zonunda (Bayburt) Eosen yaşlı intrüzif kayaçlar bulunmaktadır. Bu bölgede, bugüne kadar yaşları kesin olarak tanımlanamayan sokulumların ve içlerindeki mafik mikrogranüler anklavlar (MMA)?ın mineralojik bileşimleri, tüm kayaç jeokimyasal, Sr-Nd-Pb-O izotopik özellikleri ve radyometrik yaşları ortaya konulmuştur. İncelenen plütonik kayaçların U Pb SHRIMP zirkon yaşları 43.14 ± 0.54 ila 45.81 ± 0.48 My arasında değişir. Bu kayaçlar yaklaşık KD-GB uzanımlı olup, boyutları 3-22 km2 arasında değişir. Bileşimleri diyoritten granite kadar değişmekte olup, başlıca mineralleri plajiyoklas (An02-68), ortoklas (Or01-96), amfibol (Mg#=0.03-0.93), kuvars, biyotit (Mg#=0.49-0.62), piroksen (En37-57 Fs12-45 Wo2- 48), magnetit ve ilmenit oluşturur. Genel olarak I-tipi, düşük-yüksek K?lu kalk-alkali, genellikle metalümin az oranda da peralümin karakterlidirler. Kondirite göre normalleştirilmiş nadir toprak element dağılımları konkav şekilli (LaN/LuN=2.53?12.22) olup, negatif Eu anomalisi (Eu/Eu*=0.31?0.92) gösterirler. Ana ve iz element değişimleri, kayaçların gelişiminde plajiyoklas, amfibol, piroksen ve Fe-Ti oksit fraksiyonlaşmasının etkili olduğunu gösterir. Kayaçların ?Nd(i) değerleri ?1.34 ve 0.92, 87Sr/86Sr(i) değerleri 0.7049 ve 0.7056 arasındadır. 206Pb/204Pb(i), 207Pb/204Pb(i) ve 208Pb/204Pb(i) içerikleri sırasıyla 18.43?18.69, 15.59?15.63 ve 38.44?38.83 arasındadır. İncelenen örneklerdeki ?18O değerleri ? 4.8 ila ? 8.8 arasında olup, I-tipi granitoyidlere benzer bileşime sahiptirler. Tüm veriler, incelenen plütonik kayaçların ana magmasının litosferik mantodan türediğini, kabuksal kayaçların katkısının nisbeten az olduğunu gösterir. İncelenen plütonik kayaçların içindeki MMA?lar diyorit, gabrodiyorit ve tonalit bileşimli olup, orta-yüksek K?lu metalümin karakterde ve ana kayadan daha düşük A/CNK (0.77-0.97) ve SiO2 (% 55-64) ve daha yüksek Na2O/K2O (4.9-7.2) oranlarına sahiptirler. İzotopik özellikleri dikkate alındığında, MMA?lar ana kayaçlara benzer Sr-Nd-Pb-O izotopik bileşimlere sahip olup, onlara nazaran daha düşük 143Nd/144Nd(i) (0.51253-0.51263) ve ?18O (6.1-7.4) değerlerine sahiptirler. Tüm bu veriler dikkate alındığında, MMA?lar ana kaya içerisinde soğumuş olan eş yaşlı mafik magmanın küçük kütlelerini temsil eden magma karışım ürünleri olarak kabul edilebilirler. İncelenen plütonlar ve içlerindeki MMA?larda hesaplanan kristalizasyon basınçları birbirine yakın değerlerde olup, ana kayaçlarda 0.1?2.6 kbar, MMA?larda ise 0.1?2.9 kbar arasındadır. Kristallenme sıcaklıkları ise ana kayaçlarda 506-1172 °C, MMA?larda ise 467-1155 °C arasında değişmektedir. Tüm bu veriler Eosen yaşlı plütonik kayaçların nisbeten sığ derinliklere (~ 5 to 9 km) yerleşmiş olduklarını ifade eder.
- MakaleAçık Erişim2018Petrography, mineral chemistry and crystallization conditions of cenozoic plutonic rocks located to the north of Bayburt (Eastern Pontides, Turkey)
Kaygusuz, Abdullah; Yücel, Cem; Arslan, Mehmet; Sipahi, Ferkan; Temizel, Irfan; Çakmak, Gökhan; Güloglu, Z. Samet
The Eastern Pontides comprise many intrusive bodies varying in composition, size and age from Palaeozoic to Cenozoic. Especially Cenozoic aged bodies are commonly observed in the southern part, while they are rarely exposed in the northern part of the Eastern Pontides. In this study, the petrography and mineral chemistry of the Cenozoic aged Çiçekli, Somarova, Sorkunlu, Şaşurluk, Aydintepe, Kemerlikdagi and Pelitli plutons located to the north of Bayburt are determined, and the crystallisation conditions of the studied bodies were estimated by means of thermobarometer calculations. The studied plutons extend mostly in NE-SW directions and are approximately ellipsoid in shape. The contacts between the plutons and surrounding rocks are sharp, and plutons commonly contain mafic microgranular enclaves (MMEs) of different sizes. Petrographic and mineral chemistry studies reveal some disequilibrium textures reflecting the magma mixing process. Based on modal mineralogy, the plutonic rocks are gabbroic diorite, diorite, tonalite, granodiorite and monzogranite in composition. The rocks have fine to medium granular, porphyric, monzonitic, poikilitic, occasionally myrmekitic and micrographic textures. The main minerals are labradorite and albite (An68-02), magnesiohornblende and actinolite (Mg# = 0.6-0.9), diopside and augite (Wo44-46), clinoenstatite (En53-57) and Fe-Ti oxide minerals. Crystallization temperatures calculated from amphibole, biotite, clinopyroxene, magnetite and ilmenite minerals are 405°C to 1161°C, pressure values are 0.1 to 2.7 kbar, and oxygen fugacity (log10 fO2) is -20 to -12. Estimation of water content calculated by using amphiboles is between 2.9 and 6.8%. Based on obtained data, it is suggested that the studied plutons were emplaced at shallow depths (∼ 1-8 km).
- MakaleYalnız künye2018Geochemical and Sr-Nd-Pb isotope characteristics of the Miocene to Pliocene volcanic rocks from the Kandilli (Erzurum) area, Eastern Anatolia (Turkey): Implications for magma evolution in extension-related origin
Kaygusuz, Abdullah; Aslan, Zafer; Aydınçakır, Emre; Yücel, Cem; Gücer, Mehmet Ali; Şen, Cüneyt
This paper presents Sr-Nd-Pb isotopic and whole-rock geochemical data of Miocene to Pliocene volcanic rocks in the Eastern Anatolia (Turkey) aiming to unravel their sources and evolutionary history. The wide compositional range of lavas and pyroclastics includes basaltic andesite, basaltic trachyandesite, trachyandesite, andesite and trachydacite. These calc-alkaline volcanics are enriched in large ion lithophile elements and light rare earth elements and depleted in the high field strength elements. Sr-Nd isotope data indicate low values for 87Sr/86Sr(i) (0.70432–0.70464) and high values for 143Nd/144Nd(i) (0.51272–0.51282). Further, these data are within the mantle array of the isotope ratio diagram. The lead (Pb) isotopic compositions (206Pb/204Pb(i) = 18.33 to 18.62, 207Pb/204Pb(i) = 15.51 to 15.60, 208Pb/204Pb(i) = 38.10 to 38.45) reveals the presence of an enriched source. The main petrological processes involved fractional crystallization and the mixing of at least two fractionated magmas having same source characteristics. All evidence supports the findings that the Kandilli volcanic rocks were derived from a partial melting of the both spinel and garnet bearing subcontinental lithospheric mantle, which had been previously metasomatized by mostly fluids derived from subducted slab during the collisional and post-collisional extension-related geodynamic setting in the Eastern Anatolia region of Turkey.
- MakaleAçık Erişim2018Mineral chemistry, whole-rock geochemistry and petrology of Eocene I-type shoshonitic plutons in the Gölköy area (Ordu, NE Turkey)
Temizel, Irfan; Abdioǧlu Yazar, Emel; Arslan, Mehmet; Kaygusuz, Abdullah; Aslan, Zafer
The Eocene intermediate to felsic plutons are widespread in varying sizes and compositions throughout the Eastern Pontides Orogenic Belt in NE Turkey. Of these, two monzonitic bodies (namely the Eriko Tepe and Göl Tepe Plutons) in the Gölköy (Ordu) area, extend nearly in the orientation of NWSE and E-W and were emplaced into the Upper Cretaceous and/or Eocene volcanic and sedimentary rocks. Petrographically, the studied monzonitic plutons are compositionally fine to medium grained monzonite, monzodiorite and subordinate quartz-monzonite. They consist of plagioclase (An35-67), K-feldspar (Or61-96), quartz, clinopyroxene (Wo28-49En35-51Fs10-25), biotite (Mg#: 0.53-0.73) ± hornblende (Mg#: 0.65-0.82), Fe-Ti oxide with monzonitic, poikilitic, perthitic, rare antirapakivi and graphic textures. Mineral thermobarometer estimations imply that the plutons were crystallized in P-T conditions of mid to shallow crustal levels. Petrochemically, these monzonitic plutons show post-collisional, I-type, metaluminous (A/CNK=0.76-0.93) and shoshonitic features. The wholerock major oxide and trace element variations suggest that fractionational crystallization played a significant role in the evolution of these monzonitic plutons. The primitive mantle-normalized trace element patterns of the studied plutons are similar to each other with enrichment in large ion lithophile elements, Th, Ce and negative Nb and Ti anomalies. Moreover, the chondrite-normalized rare earth element plots of the plutons show moderately enriched concave-shaped patterns (LaN/LuN=9.3-12.6) with negative Eu anomalies (EuN/Eu∗=0.69-0.84), all of which imply plagioclase and clinopyroxene ± hornblende fractionations during their evolution. The geochemical data suggest that the monzonitic plutons have evolved from parental magmas derived from the melts of enriched lithospheric mantle, in a post-collisional setting.
- Proje2017Granitoidlere (Gümüşhane, Kd Türkiye) Bağlı Gelişen Skarn Cevherleşmelerinin Jeolojisi, Jeokimyası Ve Jeokronolojisinin Araştırılması
Saydam Eker, Çiğdem; Kaygusuz, Abdullah; Vural, Alaaddin; Sipahi, Ferkan
Kopuz Fe ve Karadağ Fe-Cu skarn cevherleşmeleri Gümüşhane'nin (KD Türkiye) kuzeybatısında bulunmaktadır. Kopuz ve Karadağ (Torul, Gümüşhane) çevresinde granitoyid, tortul ve volkanik kayaçlar yer almaktadır. Kopuz Granitoyidi 79.9 My, Karadağ Granitoyidi 44 My yaşlı olarak belirlenmiştir. Kopuz?da kireçtaşı ile volkanitlere 79.9 My yaşlı granitoyidin sokulumu ile dokanak metamorfizması ve skarn zonu gelişmiştir. Kopuz Fe skarn cevherleşmesine sebep olan granitoyid yüksek K?lu kalk-alkali karakterde ve metalimünyum özellikte olup yay granitlerine benzerlik göstermektedir. Granodiyoritten kireçtaşına doğru endo- ve ekzoskarn zonları gelişmiştir. Skarn zonunda piroksen, granat, biyotit-flogopit, amfibol, epidot, kuvars, kalsit ve aktinolit mineralleri oluşmuştur. Skarn zonunda piroksen türü diyopsitik hedenberjit ve diyopsit, granat türü andradit ile grossular andradittir. Kopuz Fe skarn cevherleşmesinde cevher minerallerinin parajenezi manyetit, pirit ve hematit şeklinde belirlenmiştir. Karadağ?da 44 My yaşlı granitoyidlerin Geç Kretase yaşlı kireçtaşı ve volkanitlere sokulumu sonucu skarn cevherleşmesi oluşmuştur. Karadağ Fe-Cu skarn cevherleşmesine sebep olan granitoyid yüksek-orta K?lu kalk-alkali karakterde olup kuvars monzonit, granodiyorit ve kuvars porfirler peralimünyum; diyoritler metalimünyum özellikte ve genelikle yay granitlerine benzerlik göstermektedir. Karadağ Fe-Cu skarn cevherleşmesinin ekzoskarn zonundaki skarn mineralleri piroksen, granat, epidot, kuvars ve kalsittir. Karadağ Fe-Cu skarn cevherleşmesinde piroksenler diyopsit olup çok az hedenberjit, vollastonit veya johansinit bileşiminde, granatlar ise andradit ile grossular andradittir. Cevher minerallerinin parajenezi manyetit, pirit, hematit ve kalkopiritten oluşmaktadır. Kopuz Fe skarn cevherleşmesindeki granitoyidlerdeki apatit ve zirkon termometre hesaplamalarında yerleşim sıcaklığı 758-907 ºC arasındadır. Kopuz Fe skarn cevherleşmesinin ekzoskarn zonunda andradit-diyopsit çiftinin mineral kimyasından 344-434 oC arasında sıcaklık değerleri belirlenmiştir. Karadağ Fe-Cu skarn cevherleşmesi çevresindeki granitoyidlerde apatit ve zirkon termometresi yerleşim sıcaklığı 668-1021 ºC arasında hesaplanmıştır. Karadağ Fe-Cu skarn cevherleşmesinde ekzoskarn zonunda andradit-hedenberjitik diyopsit ve grossular andradit-diyopsit çiftinin mineral kimyasından 412- 503 oC arasında sıcaklık değerleri belirlenmiştir. Kopuz Fe ve Karadağ Fe-Cu skarn cevherleşmelerinde ekzoskarn zonu kuvars ve kalsit mineralleri sıvı kapanımları birincil ve Tip I kapanımlardır. Kopuz?da homojenleşme sıcaklığı 224-349 °C ve tuzluluk % 4.18 (NaCl eşdeğeri tuzluluk); Karadağ?da ise sırasıyla 175-430 oC ve % 0.2-14.8 (NaCl eşdeğeri tuzluluk) arasında belirlenmiştir. Sıvı kapanım verileri skarn kökeni desteklemekle birlikte nispeten farklı iki sıvının izotermal karışımı ile soğumanın mineral çökeliminde etkili olduğunu belirtmektedir. Kopuz Fe ve Karadağ Fe-Cu skarn cevherleşmelerinde piritin manyetit ve hematitle birlikte az miktarda olması, Kopuz Fe skarn cevherleşmesindeki piritin S-izotop değerinin dar bir aralıkta değişmesi ve magmatik kaynağı göstermesi her iki cevherleşmeyi oluşturan sıvıların başlangıçta kükürt içeriğini desteklemekte olup düşük ?S ve yüksek ?O2 ortam şartlarında oluştuğunu belirtmektedir. Kopuz Fe skarn cevherleşmesinde skarn mineralleri olarak diyopsitik hedenberjit ve diyopsit, andradit ve grossular andradit, epidot, bol manyetit, hematit ve çok az piritin olması; Karadağ Fe-Cu skarn cevherleşmesinde ise diyopsit, andradit ve grossular andradit, epidotun, manyetit ve hematitce zengin, çok az kalkopirit ve piritin varlığı; sıcaklıkların 200-500oC arasında olması; her iki cevherleşmeyi oluşturduğu düşünülen sıvıların tuzluluğunun magmatik sıvıları belirtmesi; oksijen ve karbon izotop verilerinin magmatik kökeni desteklemesi, cevherleşmelerin magmatik yayda, başlangıçta kükürtlü daha sonra oksitli şartların egemen olduğu sığ sokulum oluşumunu işaret etmektedir.
- MakaleYalnız künye2017Formation of the Eğrikar (Gümüşhane) Fe–Cu skarn type mineralization in NE Turkey: U–Pb zircon age, lithogeochemistry, mineral chemistry, fluid inclusion, and O-H-C-S isotopic compositions
Sipahi, Ferkan; Akpınar, İbrahim; Eker, Çiğdem Saydam; Kaygusuz, Abdullah; Vural, Alaaddin; Yılmaz, Meltem
The Eğrikar Fe–Cu skarn type mineralization is located approximately 100 km NW of Gümüşhane in NE Turkey. Geochemical analyses of diorite, which is thought to cause skarn, indicate medium K calc-alkaline (1.3 to ~ 2.3 wt% K2O), metaluminous to peraluminous (A/CNK = 0.76 to 1.13) and resembles a continental arc granite. The age of U–Pb zircon obtained from diorite is 42.3 ± 1.0 Ma, which reflects the age of skarn metasomatism after intrusion into Late Cretaceous sandy carbonates. Skarn formation zones are recognized as endo- and exoskarn. The endoskarn zone mainly consists of pyroxene with hedenbergite (Di4.31–28.14Hd59.29–80.82Jo5.0–35.55) at prograde stage. Mn content of pyroxene increases a slight from endo to exoskarn. Pyroxene is replaced by epidote and hornblende at the retrograde stage. The exoskarn zone comprises garnet with andradite (Ad91-99Gr01–07) and grossular-andradite (Ad44-95Gr05–54), epidote and quartz as silicate minerals, and magnetite and hematite as ore minerals. Magnetite is the abundant ore mineral and is accompanied by chalcopyrite and minor pyrite at retrograde stage. On the basis of fluid inclusion values of minerals, the temperature range for hedenbergite in endo-exoskarn is 350 °C–425 °C, for epidote in exoskarn is 365 °C–376 °C, and for quartz in exoskarn 200 °C–380 °C. NaCl equivalent salinity for hedenbergite 6.88–10.73 wt% and for quartz is 3.9–15.38 wt. The δ18O values of hedenbergite is 4.1 to 4.7‰ and for garnet 3.4‰ at prograde stage, for epidote 7.9–9.2‰, for magnetite 1 to 4.4‰, for hematite − 2.9 to − 1.6‰ and for quartz range between 8.5‰ and 15.2‰. The δ18O value of epidote suggests that oxygen is a magmatic fluid whereas hedenbergite, garnet, quartz and magnetite show the mixing of magmatic and meteoric fluids. In addition, the C isotope values (− 3.2 to 2.8‰) of calcite and marble in Eğrikar Fe–Cu skarn reflect those of metamorphic, and skarns. Based on oxygen isotope data from mineral pairs, the retrograde skarn formation is characterized by epidote–magnetite assemblage formed at 255 °C–438 °C. Fluid oxygen isotope compositions of magnetite and epidote pairs of the exoskarn skarn zone indicate a mixing of magmatic and meteoric fluids with narrow δ18O values between 7.17‰ and 8.9‰. The δ34S values of the pyrites exhibit a narrow range of 3‰ and 4.4‰, thereby indicating that sulfur were probably leached from magmatic rocks. Based on the field and laboratory observation, mineral chemistries, fluid inclusion studies and isotope composition analysis, it is suggested that the Eğrikar Fe–Cu skarn mineralization occurs in a magmatic origin fluids being initially under reduced conditions, subsequently under oxidized conditions, and at shallow depth.
- MakaleYalnız künye2016Mescitli (Torul/Gümüşhane) ve Çevresindeki Eosen Yaşlı Volkanik Kayaçların Petrografik, Jeokimyasal ve Petrolojik Özellikleri
Kaygusuz, Abdullah; Şahin, Kübra
Doğu Pontid'lerin Güney Zonunda Mescitli (Torul/Gümüşhane) ve çevresinde yüzeylenen Eosen yaşlı volkanik kayaçlar mineralojik, petrografik ve jeokimyasal olarak incelenmiştir. Mescitli volkanitleri bazaltik andezit, bazaltik traki andezit, traki andezit, andezit, dasit ve riyolit bileşiminde olup, başlıca plajiyoklas, alkali feldispat, kuvars, hornblend, ojit ve biyotit minerallerinden oluşurlar. Volkanitler kalk-alkali karakterli olup, orta-yüksek K içeriğine sahiptirler. Büyük iyon yarıçaplı litofil elementler ve hafif nadir toprak elementlerce zenginleşmiş, yüksek çekim alanlı elementler bakımından tüketilmişlerdir. Kondrite normalize edilmiş nadir toprak element dağılımları, düşük-orta derecede zenginleşmeyle konkav şekilli olup (LaN/LuN=514), volkanitleri oluşturan kayaçların benzer kaynaktan itibaren oluştuklarını gösterirler. Volkanitlerin gelişiminde başlıca ayrımlaşma, daha az oranda da özümleme ± magma karışımı rol oynamıştır. Tüm bu veriler, volkanitlerin köken magmasının muhtemelen daha önce yitimle ilişkili olaylardan türeyen sıvıların metazomatizması yoluyla zenginleşmiş, yarı kıtasal litosferik manto kaynağı olabileceğini gösterir
- Proje2016Avliyana (Torul-Gümüşhane) Antimonit Cevherleşmesinin Jeolojisi-Mineralojisi ve Kökeninin Araştırılması
Kaygusuz, Abdullah; Vural, Alaaddin
Projenin amacı, Gümüshane Torul Ilçesi sınırları içinde bulunan Avliyana antimonit cevherlesmesinin; jeolojisi, mineralojik özellikleri ve kökeninin arastırılmasıdır. Avliyana antimonit cevherlesme sahasında, Üst Kretase yaslı sedimanter kayaç arakatkılı andezit lav ve piroklastlar ve bu kayaçlara sokulum yapmıs Eosen yaslı diyorit, kuvars diyorit, kuvars monzodiyorit bilesimli intrüzif kayaçlar yüzeylenmektedir. Sahada, granitik genç intrüzif kayaçlar ve bu kayaçların sokulum yaptıgı yankayaçlarda hidrotermal damar tipte gelismis antimonit cevherlesmesi mevcuttur. Cevherlesmenin oldugu bölgede yaygın olmamakla birlikte, silislesme, killesme, hematitlesme, limonitlesme, yer yer epidotlasma ve kloritlesmeler seklinde hidrotermal alterasyonlar gözlenmistir. Antimonit cevherlesmelerinin 20?100 cm arasında degisen kalınlıklardaki silislesmelerin gelistigi hematize-limonitize zon içinde 2-10 cm arasında degisen kalınlıklarda olustugu tespit edilmistir. Sb cevherlesmesi ile Ag ve Au elementi arasında çok güçlü olmamakla birlikte dogru orantılı bir iliski görülmüs, Sb cevherlesmesinin yogunlastıgı kesimde Clark degerlerine göre bir miktar yüksek Ag ve Au degerlerinin oldugu tespit edilmistir. Sıvı kapanım çalısmalarında homojenlesme sıcaklıkları 150-380 oC arasında, ortalama 234 oC bulunmustur. Cevherlesmeyle iliskili sıvıların tuzlulugun ise düsük oldugu tespit edilmistir (% 0.16- 3.67 NaCl esdegeri). Cevherlesme ile iliskili oksijen ve kükürt izotop verileri dikkate alındıgında, cevherlesmeyi olusturan akıskanların magmatik kökenli oldugu, meteorik suların da cevherlesmede katkı verdigi anlasılmıstır (?18O, silikatlarda, süfatlarda ise ? 8.0 ile 11.0 arasında; ?34S antimonit minerallerinde ? -0.2 ile 1.47 arasında; sülfatlarda ? 2.3 ile 14.1 arasındadır). Alterasyon ürünü serizit ve illitlerden yapılan K-Ar ve granitik kayaçlardan yapılan U-Pb analizlerinde 44.17±0.49 Ma ile 45.60 ±0.55 Ma arasında degisen yaslar tespit edilmis olup, sahadaki cevherlesmenin Avliyana granitoyidinin sokulumu ile iliskili oldugu sonucuna varılmıstır.
- Proje2016Egrikar (Torul, Gümüshane, Kd Türkiye) Skarn Cevherlesmesinin Mineral Kimyası, Sıvı Kapanım Ve Duraylı Izotop Bilesimlerinin Arastırılması
Saydam Eker, Çiğdem; Kaygusuz, Abdullah; Vural, Alaaddin; Sipahi, Ferkan
Egrikar Fe?Cu skarn yatagı Gümüshane?nin (KD Türkiye) yaklasık 100 km kuzeybatısında bulunmaktadır. Inceleme alanı, tabanda Geç yaslı Kretase Egrikar Monzograniti, bunun üzerine sırasıyla andezit, kireçtası içeren dasit ve hornblenli andezitten olusmaktadır. Bu kayaçlar Orta Eosen yaslı Erik Granitoyidi (granodiyorit ve diyorit) tarafından kesilmektedir. Andezitler, porfirik, camsı ve bosluklu dokuda olup plajiyoklaslardan olusmaktadır. Dasitik kayaçlar porfirik dokuda olup, baslıca kuvars, plajiyoklas, biyotit ve opak minerallerden olusmaktadır. Kireçtasları ise yer yer mermere dönüsmüs ve kristalize olmustur. Hornblendli andezitler mikrogranü porfirik ve glomeroporfirik dokulu olup ve plajiyoklas, hornblend, biyotit ve kuvars minerallerini içermektedir. Geç Kretase yaslı Egrikar monzograniti baslıca plajiyoklas, kuvars, ortoklas, biyotit ve muskovitten olusmaktadır. Orta Eosen yaslı Erik Granitoyidi ise granodiyorit ve diyorit bilesimli olup plajiyoklas ve hornblend minerallerinden ibarettir. Egrikar Fe-Cu skarn yatagındaki volkanitler kalk-alkali karakterdedir. Egrikar Monzograniti orta K?lu kalk-alkali bilesimde olup peralüminyum karakterdedir. Egrikar Monzogranitinin iz element karakteristikleri, genel olarak yay granitlerine benzerlik gösterirler. Erik Granitoyidi orta K?lu kalk-alkali özellikte ve metalüminyum karakterdedir. Egrikar Fe-Cu skarn sahasında Fe-skarn ile iliskili Erik Granitoyidi çarpısma sonrası meydana gelmistir. Erik Granitoyidi?nin kireçtasına sokulumu sonucu dokanak metamorfizması olusmus ve skarn zonu gelismistir. Granitoyidden kireçtasına dogru endo- ve ekzoskarn zonlarının olustugu belirlenmistir. Skarn zonunda piroksen, granat, epidot, kuvars, kalsit ve aktinolit-tremolit skarn minerallerini olusturmaktadır. Skarn zonunda piroksen türü hedenberjit, granat türü andradit ile grossular andradittir. Egrikar Fe-Cu skarn yatagının cevher minerallerinin parajenezi manyetit, pirit, hematit, kalkopirit, altın ve nabit bakırdan olusmaktadır. Ikincil cevher mineralleri olarak götit, limonit, dijenit, malakit, azurit, bornit ve lepidokrozit belirlenmistir. Egrikar Fe-Cu skarn yatagındaki endo-ekzoskarn zonunda hedenberjit, epidot ve kuvars minerallerinde yapılan sıvı kapanım çalısmalarında, sıvı kapanımlar birincil ve Tip I kapanımlar olarak sınıflandırılmıstır. Hedenberjit, epidot ve kuvarslarda yapılan sıvı kapan çalısmalarında sıcaklık 200-425 ve tuzluluk % 2.7-15.38 arasında olup skarn kökeni desteklemektedir. Hedenberjit, granat, manyetit, epidot, amfibol, kuvars ve pirit minerallerinden belirlenen oksijen ve kükürt izotop degerleri dar bir aralıkta degismekte ve magmatik kökeni desteklemektedir. Endo-ekzoskarn geçis zonu için hedenberjit-granat çiftinin mineral kimyasından 446-377 oC sıcaklık ve ekzoskarn zonunun termodinamik sartları manyetitepidot çiftinin izotop bilesiminden 255-438oC olarak belirlemistir. Sıcaklık degisimine baglı olarak düsük kükürtlü, nispeten yüksek oksitli magmatik sıvılardan itibaren mineral çökelimi gerçeklesmistir. Egrikar Fe-Cu skarn yatagında; piroksenin hedenberjit, granatın andradit ve grossular andradit türünde, bol manyetit, hematit ve çok az pirit ve kalkopirit bilesimli olması, sıvı kapanım sonucu elde edilen sıcaklık ve tuzluluk verileri ile skarn minerallerinin duraylı izotop bilesimleri bu yatagın magmatik sıvılardan baslangıçta düsük sülfürlü sonradan yüksek oksitli sartlar altında sıg sokulum sonucu olustugunu göstermektedir.
- MakaleYalnız künye2016U–Pb zircon chronology and petrogenesis of Carboniferous plutons in the northern part of the Eastern Pontides, NE Turkey: Constraints for Paleozoic magmatism and geodynamic evolution
Kaygusuz, Abdullah; Arslan, Mehmet; Sipahi, Ferkan; Temizel, İrfan
Numerous intrusive rocks of varying ages and compositions exist in the Paleozoic to Tertiary periods in the Eastern Pontides. Carboniferous intrusive rocks are commonly observed in the southern part of the Eastern Pontides. The nature of the rocks in the northern part of the region has not been determined because of Upper Cretaceous and Tertiary volcano-sedimentary units. Whole-rock geochemical, isotopic and geochronological data obtained from five different mapped granitoid bodies located in the northern part of the Eastern Pontides allow for the proper reconstruction of Carboniferous magmatism and the geodynamic evolution of the region. According to laser ablation ICP-MS U–Pb zircon dating, the Özdil, Soğuksu, Seslikaya, Kızılağaç and Şahmetlik plutons have similar 206Pb/238U vs. 207Pb/235U concordia ages of 340.7 ± 1.8 Ma and 323.1 ± 1.5 Ma, 348.4 ± 1.6 Ma, 335.4 ± 1.4 Ma, 337.2 ± 0.6 Ma and 334.5 ± 1.4 Ma, respectively. The aluminium saturation index (ASI) values of all of the samples from the plutons are between 1.0 and 1.32, which indicate peraluminous melt compositions. The plutons have SiO2 contents between 59 and 79 wt.% and show low- to high-K calc-alkaline characteristics. The plutons are enriched in large-ion lithophile and light rare earth elements and are depleted in high-field strength elements. Chondrite-normalized rare earth element patterns are characterized by concave-upward shapes and pronounced negative Eu anomalies, with LaCN/YbCN = 1.9–46.8 and EuCN/Eu* = 0.19–1.76. The studied plutons show considerable variations in 87Sr/86Sr(i) (0.70255 to 0.71006) and εNd(i) values (− 4.8 to − 7.1), as well as Nd model ages (1.15 to 2.47 Ga). The Pb-isotopic ratios are 206Pb/204Pb = 17.11–18.60, 207Pb/204Pb = 15.58–15.64 and 208Pb/204Pb = 36.95–38.62. The crystallization temperatures of the melts range from 676 to 993 °C, as determined by zircon and apatite saturation thermometry. These data suggest that the Carboniferous granitic magmas were produced by the partial melting of meta-mafic to meta-felsic lower crustal source rocks, with minor contributions from the mantle. Collectively, these rocks represent a late stage of Hercynian magmatism in the northern part of the Eastern Pontides.
- MakaleYalnız künye2015Geochronology, geochemistry, and petrogenesis of the Eocene Bayburt intrusions, Eastern Pontides, NE Turkey: Evidence for lithospheric mantle and lower crustal sources in the high-K calc-alkaline magmatism
Kaygusuz, Abdullah; Öztürk, Mürşit
Eocene I-type plutons are widespread in the Eastern Pontides, Northeastern Turkey. Geochemical and isotopic results on two Eocene intrusive bodies located in the southern zone of the Eastern Pontides were utilized to achieve a proper reconstruction of their origin. Based on laser ablation ICP-MS U-Pb zircon dating, Kiliçkaya and Kozluk intrusions present similar 206Pb/238U versus 207Pb/235U concordia ages of 46.75±0.79 and 46.9±0.68 Ma, respectively. Both intrusions exhibit similar petrographical, geochemical, and isotopical features, and contain abundant mafic microgranular enclaves (MMEs). The intrusive rocks are composed of diorite, tonalite, and granodiorite, whereas MMEs are composed of diorite. Both the intrusive rocks and the MMEs are I-type, high-K calc-alkaline in composition and display a metaluminous character. They are enriched in large-ion lithophile and light rare-earth elements and are depleted in high-field strength elements. The intrusive rocks show moderate variation in 87Sr/86Sr(i) (0.70531-0.70576), εNd(i) (+0.3 to -0.5), and δ18O values (+6.6 to +6.9), as well as Nd model ages (0.73-0.82Ga). Their Pb isotopic ratios are 206Pb/204Pb=18.67-18.86, 207Pb/204Pb=15.61-15.62, and 208Pb/204Pb=38.62-39.03. Although the isotope signatures of MMEs (87Sr/86Sr(i)=0.70528-0.70561; εNd(i)=+0.7 to -0.3; δ18O=+6.7 to +6.8) are significantly similar to those of the host rocks, the MMEs are characterized by relatively low contents of SiO2 (57-59wt.%), low aluminum saturation index (0.8-0.9), and high Mg numbers (31-36). All of these data suggest magma generation by mixing of enriched lithospheric mantle- and lower crustal-derived melts. Moreover, Sr-Nd isotopic modeling reveals ~17% to 23% lower crustal magma contribution to the mantle component.
- MakaleYalnız künye2014K-Ar dating, whole-rock and Sr-Nd isotope geochemistry of calc-alkaline volcanic rocks around the Gümüşhane area: Implications for post-collisional volcanism in the Eastern Pontides, Northeast Turkey
Aslan, Zafer; Arslan, Mehmet; Temizel, Irfan; Kaygusuz, Abdullah
Volcanic rocks from the Gümüşhane area in the southern part of the Eastern Pontides (NE Turkey) consist mainly of andesitic lava flows associated with tuffs, and rare basaltic dykes. The K-Ar whole-rock dating of these rocks range from 37.62 ± 3.33 Ma (Middle Eocene) to 30.02 ± 2.84 Ma (Early Oligocene) for the andesitic lava flows, but are 15.80 ± 1.71 Ma (Middle Miocene) for the basaltic dykes. Petrochemically, the volcanic rocks are dominantly medium-K calc-alkaline in composition and show enrichment of large ion lithophile elements, as well as depletion of high field strength elements, thus revealing that volcanic rocks evolved from a parental magmas derived from an enriched mantle source. Chondrite-normalized rare-earth element patterns of the volcanic rocks are concave upwards with low- to-medium enrichment (LaCN/LuCN = 3.39 to 12.56), thereby revealing clinopyroxene- and hornblende-dominated fractionations for andesitic-basaltic rocks and tuffs, respectively. The volcanic rocks have low initial 87Sr/86Sr ratios (0.70464 to 0.70494) and εNd(i) values (+1.11 to +3.08), with Nd-model ages (TDM) of 0.68 to 1.02 Ga, suggesting an enriched lithospheric mantle source of Proterozoic age. Trace element and isotopic data, as well as the modelling results, show that fractional crystallization and minor assimilation played an important role in the evolution of the volcanic rocks studied. The Eocene to Miocene volcanism in the region has resulted from lithospheric delamination and the associated convective thinning of the mantle, which led to the partial melting of the subduction-metasomatized lithospheric mantle.
- MakaleYalnız künye2014LA-ICP MS zircon dating, whole-rock and Sr-Nd-Pb-O isotope geochemistry of the Camiboǧazi pluton, Eastern Pontides, NE Turkey: Implications for lithospheric mantle and lower crustal sources in arc-related I-type magmatism
Kaygusuz, Abdullah; Arslan, Mehmet; Siebel, Wolfgang; Sipahi, Ferkan; Ilbeyli, Nurdane; Temizel, Irfan
Late Cretaceous I-type plutons are widespread in the Eastern Pontides, NE Turkey. The studied Camiboǧazi pluton is a composite pluton consisting of diorite, tonalite, monzodiorite, monzonite, quartz monzonite, granite, and mafic microgranular enclaves (MMEs). Laser ablation ICP-MS U-Pb dating of zircon yielded crystallization ages of 76.21±0.79Ma, 75.65±0.50Ma, 75.04±0.83Ma, and 74.73±0.86Ma for diorite, monzodiorite, monzonite, and granite, respectively. The rocks of the pluton have I-type, high-K to shoshonitic and metaluminous character, displaying whole-rock geochemical features of arc-related granites. They are enriched in large-ion lithophile and light rare-earth elements, and depleted in high-field-strength elements. Major element variations can be attributed to fractionation of plagioclase, clinopyroxene, hornblende, and Fe-Ti oxides. The rocks show considerable variation in 87Sr/86Sr(i) (0.70498 to 0.70622), εNd(i) (-2.79 to -0.36), δ18O values (+6.3 to +11.4) and Nd model ages (TDM) (0.81Ga to 1.26Ga). Besides, they have (206Pb/204Pb)=18.44-19.09, (207Pb/204Pb)=15.64-15.69, and (208Pb/204Pb)=38.37-38.89. Although isotope signatures of the mafic microgranular enclaves (MMEs) (87Sr/86Sr(i)=0.70551 to 0.70622; εNd(i)=-2.9 to -1.23; δ18O=+8.3 to +9.7) are largely similar to the host rocks, MMEs are characterized by relatively high Mg-numbers (32-36), low contents of SiO2 (52-56wt.%) and low ASI (0.7-0.9). Estimated crystallization temperatures for the rocks of the pluton range from 735±58°C to 844±24°C and a shallow intrusion depth (<10km) is estimated from Al-in-hornblende thermobarometry. Whole-rock geochemical and isotopic data suggest magma generation by dehydration melting of an amphibolite-type lower crustal component with additional input of a subcontinental lithospheric mantle component. Furthermore, Sr-Nd isotope mixing model reveals ~30% to 40% lower crustal magma contribution to the mantle component.
- Proje2013Doğu pontid kuzey zonunda yüzeylenen paleozoyik yaşlı granitlerin U-Pb zirkon yaşlandırması, Sr-Nd-Pb-O izotop sistematikleri ve jeodinamik evrimi
Kaygusuz, Abdullah; Arslan, Mehmet; Sipahi, Ferkan
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- MakaleAçık Erişim2013Petrogenesis of the late Cretaceous Turnagöl intrusion in the eastern Pontides: Implications for magma genesis in the arc setting
Kaygusuz, Abdullah; Sipahi, Ferkan; Ilbeyli, Nurdane; Arslan, Mehmet; Chen, Bin; Aydinçakir, Emre
A series of Cretaceous plutons is present in the eastern Pontides of northeastern Turkey. The Turnagöl intrusion is the least studied and, thus, the least understood plutons in the orogen. This intrusion consists of hornblende-biotite granodiorites emplaced at 78 Ma based on LA-ICP-MS U-Pb zircon dating. It is of sub-alkaline affinity, belongs to the medium- to high-K calc-alkaline series, and displays features typical of I-type granites. The rocks of the intrusion are enriched in large-ion lithophile elements and light rare earth-elements with negative Eu anomalies (Eu/Eu* = 0.69-0.82), but are deficient in high-field-strength elements. They have a small range of ( 87Sr/86Sr)i (0.7060-0.7063), ÉNdi(-2.6 to -3.1), and δ18O (+8.1 to +9.1) values. Their Pb isotopic ratios are 206Pb/204Pb = 18.63-18.65, 207Pb/ 204Pb = 15.62-15.63, and 208Pb/204Pb = 38.53-38.55. The fractionation of plagioclase, hornblende, and Fe-Ti oxides had key functions in the evolution of the Turnagöl intrusion. The crystallization temperatures of the melts ranged from 758 to 885 C as determined by zircon and apatite saturation thermometry. All these characteristics, combined with the low values of K2O/Na2O and (Na 2O + K2O)/(FeOt + MgO + TiO2), as well as the high values of (CaO + FeOt + MgO + TiO2), suggest an origin by dehydration melting from a metabasaltic lower crustal source.
- Proje2012Doğu pontid kuzey zonu ve kuzey-güney zon geçişinde yüzeylenen kretase-paleosen yaşlı granitoyidik sokulumların petrokimyası, Sr-Nd-Pb-O izotop jeokimyası, jeokronolojisi ve jeodinamik gelişimi
İlbeyli, Nurdane; Kaygusuz, Abdullah; Arslan, Mehmet; Sipahi, Ferkan
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