Çalışmanın konusunu oluşturan kalsedonlar Tokat merkeze bağlı Nebi Köy ve çevresinde bulunmaktadır. Kalsedonlar Permiyen-Triyas yaşlı metamorfik kayaçlar içerisinde birkaç mm’den 10 cm kalınlığa kadar ulaşan damarlar halinde gözlenmektedir. Açık mavi-mavi tonlarında renge sahip olan genellikle bantlı yapıda olup yer böbreğimsi yapı da sunmaktadır.
 Çalışma alanından alınan kalsedon örnekle...

Abstract The impact origin of the Early Cretaceous (140.82 ± 0.51 Ma) 20‐km diameter Dellen structure was proven in late 60s based on discovery planar deformation features (PDFs) quartz grains. Although decades have passed, impactites found from crater not received much attention. Thus, this study provides a detailed petrological and mineralogical description Dellen. Impactites were classified ...

this paper presents the petrographic examination results on the thirteen pottery sherds from the first season of excavation of tepe gratziani in sistan plain. in order to specify whether the pottery were local or imported, conducted experiments have been performed by polarizing microscope of jame swift model in the petrographic lab of the institute of cultural heritage which based on the review...

the qom formation, which hosts the mazraeh celestite deposit, contains dominantly limestones, marl and subordinate evaporites deposited in shallow marine environments. petrographic evidence indicates that the celestite deposits were formed by replacement of limestone. the presence of carbonate inclusions within celestite crystals as well as the pseudomorphic habits of some crystals suggests tha...

<p style="text-indent:20px;">The spectral norm and the nuclear of a third order tensor play an important role in completion recovery problem. We show that is equal to square root three positive semi-definite biquadratic tensors, roots norms those tensors are lower bounds tensor. This provides way estimate evaluate Some upper for tensor, by radii some symmetric matrices, presented.</p>