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- MakaleAçık Erişim2023Scopus SJRQ2A study on the magnetite skarn mineralization (Gümüşhane, Türkiye): a magnetic survey
Sipahi, Ferkan; Sadiklar, M. Burhan; Gücer, Mehmet Ali; Aydin, Ali; Kara, Rasim Taylan
Iron (Fe)-skarn mineralizations (Çambaşı, Dereli, Eğrikar, Karadağ, Kopuz, Sekü, Donguldere, Arnastal, Özdil, Ögene, İkizdere, Ovit Dağı, Kartiba, etc.) in the eastern part of the Pontides (NE Türkiye) are accommodated in the Pontide paleomagmatic arc and the eastern part of the Pontides Metallogenic Belt containing numerous various deposits. Fe-skarn mineralization around the Arnastal Plateau (Gümüşhane-Türkiye) is fragmentary in this area, which is covered with plants (grasses, flowers, etc.). Thus, it was attempted to describe the subsurface structures and Fe mineralization using an interpretation of the available geological and existing magnetic data in this area. Granitoid and volcano-sedimentary series (Upper Cretaceous) outcrop in the study area. These volcanosedimentary series consist of limestone, sandy limestone, marl, andesite, quartz andesite, basalt, and their equivalent pyroclastics. They include a thin layer of the red limestone (Upper Cretaceous) and olistolith recrystallized limestones (Jurassic-Lower Cretaceous). Zigana granitoid, intruding into all of these rocks, is high-K calc-alkaline and metaluminous and is classified as quartz monzonite, monzogranite, granite, and syenogranite as a result of its modal composition. Contact pyrometasomatic mineralization occurs in between the limestone and granitoids in the Arnastal Plateau. In addition to petrographic and mineralogical studies, magnetic methods were applied to an area of approximately 10 km2 to find any covered Fe deposits. Magnetic susceptibility values measured on the outcropped rocks ranged from 1 to 34 (10–7 SI) for limestone, 78 to 3750 (10–7 SI) for basalt, and 105 to 3946 (10–7 SI) for granitoids. It is considered that these ranges express the alteration (physical or chemical) of the rocks, their homogeneity, and the lack or presence of Fe minerals. The magnetic survey was conducted along a study area measuring 12,075 m long with 25 and/or 50 m station spacing. Processing of the magnetic data revealed the presence of eight buried Fe ores that could represent either massive or disseminated mineralization between the Sarıtaş and Kurtdere plateaus. Magnetite ore bodies may be present from the surface to a depth of approximately 15–25 m inside the limestone. In addition to the identification of new magnetite ore mineralization or bodies, a new geological map was designed by determining probable formation boundaries with this magnetic survey.
AtıfScopus3WoS2OpenAlex3TR Dizin1
İncele - MakaleYalnız künye2008Scopus SJRQ1An application of the interaction matrices method for slope failure susceptibility zoning: Dogankent settlement area (Giresun, NE Turkey)
Ceryan, Nurcihan; Ceryan, Sener
Large-scale instability phenomena frequently occur in slopes in such geologically complex areas as Dogankent in NE Turkey. This study presents an application of the interaction matrices (IM) methodology, as a semi-qualitative method sensitive to large-scale slope instability. For both rock and soil slopes, the main interactive factors were distance from faults, degree of weathering and slope angle. Using IM, a slope failure susceptibility map was created for the Dogankent area and checked again field evidence. The results indicated that IM could be a useful method for slope stability assessment.
AtıfScopus24OpenAlex22İncele - MakaleYalnız künye2008Scopus SJRQ1Petrochemistry and petrology of I-type granitoids in an arc setting: The composite Torul pluton, Eastern Pontides, NE Turkey
Kaygusuz, Abdullah; Siebel, Wolfgang; Şen, Cüneyt; Satir, Muharrem
The Upper Cretaceous Torul pluton, located in the Eastern Pontides, is of sub-alkaline affinity and displays features typical of volcanic arc granitoids. It is a composite pluton consisting of granodiorite, biotite hornblende monzogranite, quartz monzodiorite, quartz monzonite and hornblende biotite monzogranite. The oldest syenogranite (77.9 ± 0.3 Ma) and the youngest quartz diorite form small stocks within the pluton. Samples from the granodiorites, biotite hornblende monzogranites, quartz monzodiorites, quartz monzonites and hornblende biotite monzogranites have SiO2 between 57 and 68 wt% and display high-K calc-alkaline, metaluminous to peraluminous characteristics. Chondrite-normalized REE patterns are fractionated Lacn/Lucn = 6.0-14.2) with pronounced negative Eu anomalies (Eu/Eu* = 0.59-0.84). Initial εNd(i) values vary between -3.1 and -4.1, initial 87Sr/86 Sr values between 0.7058 and 0.7072, and δ18O values between +4.4 and +7.3‰. The quartz diorites are characterized by relatively high Mg-number of 36-38, low contents of Na2O (2.3-2.5 wt%) and SiO2 (52-55 wt%) and medium-K calc-alkaline, metaluminous composition. Chondrite-normalized REE patterns are relatively flat [(La/Yb)cn = 2.8-3.3; (Tb/Yb)cn = 1.2] and show small negative Eu anomalies (Eu/Eu*= 0.74-0.76). Compared to the other rock types, radiogenic isotope signatures of the quartz diorites show higher 87Sr/ 86Sr (0.7075-0.7079) and lower εNd(i) (-4.5 to -5.3). The syenogranites have high SiO2 (70-74 wt%) and display high-K calc-alkaline, peraluminous characteristics. Their REE patterns are characterized by higher Lacn/Lucn (12.9) and Eu/Eu* (0.76-0.77) values compared to the quartz diorites. Isotopic signatures of these rocks [εNd(i) = -4.0 to -3.3; 87Sr/86Sr(i) = 0.7034-0.7060; δ18 O = + 4.9 to + 8.2] are largely similar to the other rock types but differ from that of the quartz diorites. Fractionation of plagioclase, hornblende, pyroxene and Fe'Ti oxides played an important role in the evolution of Torul granitoids. The crystallization temperatures of the melts ranged from 800 to 900°C as determined from zircon and apatite saturation thermometry. All these characteristics, combined with low K2 O/Na2O, low Al2O3/(FeOT + MgO + TiO2), and low (Na2O + K2O)/ (FeOT + MgO + TiO2) ratios suggest an origin through dehydration melting of mafic lower crustal source rocks.
AtıfScopus181OpenAlex156İncele