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ELDİVAN OFİYOLİTİ'NE (ÇANKIRI) AİT HARZBURJİTİK TEKTONİTLERİN MİNERALOJİK, PETROGRAFİK VE JEOKİMYASAL ÖZELLİKLERİ

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Abstract (2. Language): 
The Eldivan Ophiolite is located at the central part of the İzmir-Ankara-Erzincan Ophiolitic Belt and between Şabanözü, Eldivan and Korgun towns. Ophiolite consists of volcanic-sedimentary series, metamorphic series, tectonites, cumulates and sheeted dikes from bottom to top. Tectonites, which are the main subject of the study, are generally represented by harzburgites and occassionally include dunite, pyroxenolite and chromitite levels. Harzburgites display of traces of plastic deformation (foliation, lineasyon, fold) A clear orientation in minerals can be observed as a result of in the tectonic sequence and grinding mechanisms. The degree of deformation decreases upwards. Harzburgites are generally composed of olivine (60-90%) and orthopyroxene (10-35%). Clinopyroxene is rarely observed in the lower levels. A decrease in the amount of orthopyroxene and an increase in chromite ratio is observed in the upper levels. The composition of olivines is usually forsterite and orthopyroxene is enstatite. A slight decrease in Mg content noticed towards top direction. Furthermore, a decrease in chromium and an increase in aluminum content in chromites is observed towards top in the upwards direction. This situation can be explained by difference in the primary composition of the upper mantle and degree of partial melting processes.
Abstract (Original Language): 
Eldivan Ofiyoliti, İzmir-Ankara-Erzincan kuşağının merkezi bölümünde, Şabanözü, Eldivan ve Korgun ilçeleri arasında yer alır. Ofiyoliti oluşturan birimler alttan üste doğru, volkanik-sedimanter seri, metamorfik seri, tek-tonitler, kümülatlar ve levha dayklarından meydana gelir. Çalışmanın konusunu oluşturan tektonitler, genel olarak harzburjitlerle temsil edilir ve yer yer dünit, piroksenolit ve kromitit seviyeleri içerir. Plastik deformasyon izleri taşıyan (foliyasyon, lineasyon, kıvrım) harzburjitlerde, mineraller kristal içi kayma ve öğütülme mekanizmaları sonucunda belirgin bir yönlenme gösterir. İstifte deformasyon derecesi yukarıya doğru azalır. Olivin (%60-90) ve ortopiroksen (%10-35) minerallerinden meydana gelen harzburjitlerin alt seviyelerde az miktarda klinopiroksene rastlanır. Üst bölümlere doğru ortopiroksen miktarında bir azalma, kromit oranlarında ise bir artış gözlenir. Olivinler genellikle forsterit, ortopiroksenler enstatit bileşimindedirler ve üst kısımlara doğru Mg bakımından hafif bir fakirleşme gösterir. Kromitlerde ise, yukarıya doğru krom miktarında bir azalma, buna karşılık alüminyum mik¬tarında bir artış görülür. Bu durum üst mantonun ilksel bileşimi ve kısmi ergime süreçlerinin bir sonucu olarak açık¬lanabilir.
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