Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2016Scopus SJRQ1/r/munzur/3293
  Geochemistry of the metavolcanic rocks from the Çangaldağ complex in the central pontides: Implications for the middle jurassic arc-back-arc system in the neotethyan intra-pontide ocean

  Çimen, Okay; Göncüoğlu, M. Cemal; Sayit, Kaan

  The Cangaldağ Complex in northern central Turkey is one of the main tectonic units of the Central Pontide Structural Complex that represents the remains of the poorly known Intra-Pontide branch of the Neotethys. It comprises low-grade metamorphic rocks of intrusive, extrusive, and volcaniclastic origin displaying a wide range of felsic to mafic compositions. Petrographically the complex consists of basalts-andesites-rhyodacites and tuffs with minor amount of gabbros and diabases. On the basis of geochemistry, the Cangaldağ samples are of subalkaline character and represented by both primitive and evolved members. All rock types are variably depleted in Nb compared to LREEs, similar to the lavas from subduction-related tectonic settings. In N-MORB normalized plots, the primitive members are separated into 3 groups on the basis of levels of enrichment. The first group is highly depleted and displays characteristics of boninitic lavas. The second group is relatively enriched compared to the first group but still more depleted than N-MORB. The third group, however, is the most enriched one among the three, whose level of enrichment is around that of N-MORB. The overall geochemical features suggest that the Cangaldağ Complex has been generated with the involvement of a subductionmodified mantle source. The chemistry of the primitive members further indicates that the melts generated for the formation of the Cangaldağ Complex probably occurred in both arc and back-arc regions above an intraoceanic subduction within the Intra-Pontide branch of the Neotethys.

  AtıfScopus39·WoS39·OpenAlex31

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• MakaleAçık Erişim2013Scopus SJRQ2/r/munzur/4159
  RARE EARTH ELEMENT (REE) GEOCHEMISTRY AND GENESIS OF OIL SHALES AROUND DAGHACILAR VILLAGE, GOYNUK-BOLU, TURKEY

  Çimen, Okay; Koç, Sukru; Sari, Ali

  The study area is located in the south of Daghacilar village of Goynuk town in Bolu Province, Turkey. This study is a pioneering work in Turkey on the genesis and environmental characteristics of oil shales and other shallow marine-type sedimentary rocks regarding their major and rare earth element contents. The abundances of SiO2, Al2O3, TiO2, K2O and Fe2O3 decrease in the following order: claystone > oil shale > marl. CaO and MgO abundances are ranked in the decreasing order as follows: marl > oil shale > claystone. These results reveal the presence of two different genetic groups - detrital and marine. The same groups were also established in the correlation studies of elements. TOT/C and TOC contents of rocks observe the following order: oil shale > marl > claystone, and as a result of variations in redox conditions they also vary in a wide range. Total carbon and total organic carbon are positively correlated with the group representing clays and negatively correlated with CaO, MgO and MnO. That is why TOT/C and TOC are associated with clays. The positive correlations between some major oxides (e.g. SiO2, Al2O3, Fe2O3, TiO2 and K2O) and REE might indicate that clays and iron oxy-hydroxyls play an important role in transportation and deposition processes. The only slight negative Ce and positive Eu anomalies and Ce/Ce* and Eu/Eu* values recorded in the depositional environment indicate low oxygenated and anaerobic (reducing) conditions.

  AtıfWoS6·OpenAlex9

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