Sipahi, F.; Kaygusuz, A.; Saydam Eker, Ç.; Vural, A.; Akpınar, İ.

The geochemical and Sr–Nd–Pb isotope properties, as well as the Laser Ablation Inductively Coupled Plasma and Mass Spectrometry (LA-ICP-MS) U–Pb zircon age, of Eğrikar Monzogranite in the eastern Pontides, are primarily investigated in this study with the aim of determining its magma source and geodynamic evolution. The U–Pb zircon age obtained from Eğrikar Monzogranite is 78 ± 1.5 Ma, thereby reflecting the age of monzogranite. The I-type Eğrikar Monzogranite comprises quartz, plagioclase (An35–45), orthoclase, muscovite, and biotite. The geochemical analyses of the Eğrikar Monzogranite indicate being medium K calc-alkaline, peraluminous, and resembling magmatic arc granite. The Eğrikar Monzogranite is enriched in large ion lithophile elements and light rare earth elements relative to high field strength elements. Chondrite-normalized rare earth element patterns have concave upward shapes (LaN/YbN 2.47–8.58) with pronounced negative Eu anomalies (EuN/Eu* = 0.29–0.65). Initial εNd(i) values vary between 1.85 and 2.18 and initial 87Sr/86Sr values between 0.7048 and 0.7067. Fractionation of plagioclase, hornblende, and apatite played an important role in the evolution of Eğrikar Monzogranite. The crystallization temperatures of the melts ranged from 770°C to 919°C based on zircon and apatite saturation temperatures. The geochemical and isotopic data suggest being generated by the partial melting of mafic lower crustal sources.

Vural, A.

Geochemical and biogeochemical methods in mineral exploration have been widely used in recent years because of the depletion of known deposits and the need to explore buried deposits. The aim of this study was to investigate the gold and silver content of Helichrysum arenarium, popularly known as the golden flower, for possible exploration of precious ore deposits. For this purpose, plant samples of the respective plant parts (roots, stem-leaves and flowers) collected from Demirören village of Gümüşhane in the northeastern Turkey were analysed for gold and silver by using inductively coupled plasma mass spectrometry. Gold and silver contents of the plants was assessed on the basis of different statistical approaches. The results indicate that the plant has elevated levels of gold and silver concentrations, particularly in the case of gold. As a result, it was determined that the gold content of Helichrysum arenarium is remarkable and the gold accumulation capacity of the plant is high in the the stem-leaves, whereas the silver accumulation capacity of the plant is high in roots.

Vural, A.

Is it feasible to use K-Ar dating method in determination of the age of mineralization by utilizing alteration minerals? The purpose of this study was to examine the utility of the K-Ar dating method to accurately determine the age of mineralization. In ideal circumstances, dating of alteration products, such as illite and serisite minerals, gives the age of alteration event, which is indirectly associated with mineralization. In the study site, referred to as Avliyana, antimony mineralization (Gümüşhane, Turkey), stibnite (antimony) mineralizations of hydrothermal vein type were observed in granitic young intrusive rocks and the host rocks. In the study area, alteration was observed in the form of a small amount of weak silicification, argillitization (sericitization and illitization), hematitization, limonitization close to the mineralization and of epidotization and chloritization far from the mineralization. In order to determine the limits of the age of antimony mineralizations of the area, the K-Ar method was used to date illite and serisite minerals, which are alteration products related to mineralization. Two samples containing sericite and illite were collected from Avliyana antimonite mineralization. The alteration origin of these minerals was confirmed by supporting petrographic, XRD and scanning electron microscope studies. These samples were analysed for K-Ar dating.

Vural, A.

The element contents of sessile oak (Quercus petraea L.) leaves which grow on hydrothermally altered area with high element contents were studied at Gümüshane and its near vicinity. The aim of this study is to determine threshold element contents of Q. petraea L. leaves growing on the area. For this purpose, oak leave samples collected were analyzed by inductively coupled plasma-mass spectrometry for concentrations of some elements which were the group of most common trace elements in exploration geochemistry studies. The assessment of the element contents of the oak leaf is based on the descriptive statistics and computations of threshold values of leaves depending on statistical parameters and average element contents of the plants growing on lands in normal background values for the elements. According to Q-Q (normal quantile-quantile) plots, the Kolmogorov-Smirnov tests etc., all the elements, do not pass normality tests. Because of that, threshold values of the elements in leaves of oak were computed by median+median absolute deviation (MAD) and median+2MAD used in raw values for the elements. The data revealed that concentration levels of the examined elements in the leaves in the study area were determined as above and/or exceeded the upper limit of the normal range than in leaf of oak (Q. petraea L.) which grows on lands with normal elements background. Therefore, it is concluded that leaves of Q. petraea L. can be used as bioindicator in exploration geochemistry, especially for base metal ore deposits.