Sürdürülebilir Kalkınma Amaçları
Yayınlar
- Derleme MakaleYalnız künye2010Zigana (Gümüşhane, KD-Türkiye)volkanitlerinin alterasyon mineralojisi ve kütle değişimi
Sadiklar, M. Burhan; Sipahi, Ferkan
Doğu Karadeniz (KD-Türkiye) metalojenik provensi’nde bulunan Zigana Dağı (Gümüşhane) civarındaki Geç Kretase volkanik kayaçları yoğun hidrotermal alterasyona ve çok az yüzeysel ayrışmaya maruz kalmışlardır. Tabanda bulunan Geç Kretase bazalt, andezit ve bunların piroklastitleri yine aynı yaşlı Dasit-I ve Dasit-II olarak adlandırılan dasitik kayaçlar tarafından üstlenmektedir. Volkanik kayaçlar bimodal karakterde olup, volkanik yay ortamlarında gelişmişlerdir. Volkanitler serizit/illit-klorit fasiyesinde bozunmuşlardır ve alterasyon ürünü olarak serizit/illit, klorit, kuvars, karbonat mineralleri (ankerit ve kalsit), demir oksit ve nadiren kaolinit, simektit ve epidot içerirler. Serizitleşme/illitleşme volkanitlerinde görülen en yaygın hidrotermal alterasyon türüdür. İllitten sonra en yaygın görülen alterasyon türü klorittir. Piritleşme tüm volkanitlerde görülmekle birlikte en yaygın dasitlerde gözlenir. Bazı alanlarda, yer yer limonitleşme mevcuttur. Epidotlaşma ise nadirdir ve özellikle bazalt ve andezitlerde görülür. Hidrotermal alterasyonun bir sonucu olarak Zigana volkanitlerinde oluşan kütle kazanç ve kayıplarını hesaplamak için isocon analizi uygulanmış ve genel olarak bazalt ve andezitte %2-61 kütle kazancı, Dasit-I %71 kütle kazancı ve %42 kütle kaybı ve Dasit-II’de %44 kütle kazancı ve %32 kütle kaybı hesaplanmıştır. Dolayısıyla, ana kayacın hidrotermal alterasyonu esnasında volkanitlerde hem kütle kazancı hem de kütle kaybı meydana gelmiştir. Genellikle, az altere kayaçtan çok altere kayaca doğru illit-klorit-kaolinit artarken karbonat mineralleri azalır. Volkanitlerde, serizitleşme/illitleşme, kloritleşme ve silisleşmeye sebep olan sıvıların Cu, Pb ve Zn gibi metalleri arttırmadığı, gerçekte bu sıvıların bu metallerce fakir olduğu söylenebilir. Bu aynı zamanda onların değişik hidrotermal şartlar altında geliştiğine işaret eder.
- MakaleYalnız künye2010The Alteration Mineralogy and Mass Change of the Zigana (Gumushane) Volcanics of NE Turkey
Sipahi, Ferkan; Sadiklar, M. Burhan
The Late Cretaceous volcanic rocks around Zigana Mountain (Gumushane) in the eastern Black Sea metallogenic province in NE Turkey show intensive hydrothermal alteration but less weathering alteration. The basement of the study area is formed by Late Cretaceous basalt, andesite and their pyroclastics. These rocks are overlain by dacitic rocks of the same age, namely Dacite-I and Dacite-II. These volcanic rocks are bimodal in character and have developed in a volcanic arc environment. The volcanic rocks in the study area have been altered to the sericite/illite-chlorite facieses, and contain sericite/illite, chlorite, quartz, carbonate minerals (ankerite and calcite), iron-oxide, and rare kaolinite, smectite and epidote as the products of alteration. Sericitization/illitization is the most common type of hydrothermal alteration associated with these volcanics, and chloritization is the most common alteration type after illitization; pyritisation is seen in all volcanics, and is the most common in dacites. In some fields limonitisation is occasionally present. Epidotization is rare, and especially seen in basalt and andesite. Isocon analysis was undertaken to estimate the mass gains and losses of the Zigana Volcanics as a result of hydrothermal alteration. In general terms, the results shows that, basalt and andesite have 2-61% mass gain, Dacite-I 71% mass gain and 42 % mass loss, and Dacite-II 44% mass gain and 32% mass loss. Namely, both mass gain and mass loss occurred in the volcanics during the hydrothermal alteration of the parent materials. From less altered rock to highly altered rock there was an increase in illite-chlorite-kaolinite whereas there was a decrease in carbonate minerals. In the volcanics, fluids which cause sericitization and chloritization did not increase metals like Cu, Pb and Zn and, in fact, it can be said that these fluids are poor in point of these metals. This also shows that the metals developed under different hydrothermal conditions.
- BildiriYalnız künye2009Mineralogy and geochemistry of dacitic rocks accompanying the Murgul (Artvin, NE Turkey) massive sulfide deposit
Sipahi, Ferkan; Sen, Cueneyt; Sadiklar, M. Burhan; Demir, Yilmaz
- BildiriYalnız künye2009Alteration of Late Cretaceous dacites in the Murgul Area (Artvin, KD Turkey)
Sipahi, Ferkan; Sadiklar, M. Burhan; Sen, Cueneyt; Demir, Yilmaz
- MakaleYalnız künye2008Mineralogy, mineral chemistry, and fluid inclusion investigation of Köstere hydrothermal vein-type deposit (Gümüşhane, NE-Turkey)
Demir, Yilmaz; Uysal, Ibrahim; Sadiklar, M. Burhan; Sipahi, Ferkan
Vein type Köstere ores were deposited along cracks formed as a result of NE-SW fault system in the late Cretaceous felsic volcanic rocks in the northeastern Black Sea Region of Turkey. Total silver content of the Köstere ore is controlled by total silver content of the hydrothermal solution, homogenization temperature of the ore minerals and modal abundances of the tetrahedrite-tennantite serie minerals. The Zn/Cd ratios of sphalerites from the Köstere deposit are close to those of granite-related classical vein-type hydrothermal deposits. Furthermore Co/Ni ratio in pyrite separates, higher than unit, suggests an acidic source for the ore forming fluids. Homogenization temperatures of 200-370 °C and salinity of 0-9.85 eq. wt% NaCl were obtained on the basis of fluid inclusions studies measured in quartz minerals. These data indicate that ore formation conditions for the Köstere ore are similar with the vein-type epithermal-mesothermal deposits, related to the magmatic fluids. The overall low salinities of fluids (on average: 5.4 eq. wt% NaCl) suggest that meteoric waters were involved in mineralization. The possibility of interactions between ascending hydrothermal fluids and dilute meteoric waters is supported by geological features and mineralogical data which indicate a shallow depth of mineralization. Torul Pluton, which is the younger acidic unit (72 my) in the area, is suggested to be related to the formation of Köstere deposit.