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Full-Text Articles in Physical Sciences and Mathematics
Clay Mineral Association In The Salt Formation Of The Transylvanian Basin And Its Paleoenvironmental Significance, Nicoleta Bican-Bris̡An, Alexandru Hosu
Clay Mineral Association In The Salt Formation Of The Transylvanian Basin And Its Paleoenvironmental Significance, Nicoleta Bican-Bris̡An, Alexandru Hosu
Studia UBB Geologia
The investigated clay fraction was separated from salt samples recovered from three boreholes located in the Praid salt deposit area. For comparison, samples collected from Turda deposit (Franz Josef adit, the Rudolf and Ghizele chambers) and from the salt massif from Sărăţel were also analyzed. The qualitative investigations evidenced a clay minerals association dominated by illite and chlorite accompanied by subordinate amounts of kaolinite, smectite, fibrous clays (sepiolite, palygorskite), and in minor amounts, by 14/14 chlorite/vermiculite and chlorite/smectite interstratifications. A quantitative evaluation (%) including a standard graphical representation was performed only for the borehole samples (Praid), according to the vertical …
Characterisation Of Some Clays Used For Whiteware Ceramics, Ii. Technological Characterization, Maria Gorea, Marcel Benea
Characterisation Of Some Clays Used For Whiteware Ceramics, Ii. Technological Characterization, Maria Gorea, Marcel Benea
Studia UBB Geologia
The paper investigates the mineral composition of four diferent clay types used for whiteware ceramics, correlated to the measured mineralogical and chemical composition, particle size distribution and technological characteristics (plasticity, drying, and firing shrinkage, dry resistance). According to their particle size distribution, the U-II, U-III and ESV3 clay types are almost identically, but the mineralogical composition is different. On the other hand, the CARO clay type has a very similar kaolinite and quartz content with U-II clay, but shows a completely different particle size distribution. Based on the mineralogical and particle size distribution, CARO clay type shows the most suitable …
Characterisation Of Some Clays Used For Whiteware Ceramics I. Mineralogical Composition, Marcel Benea, Maria Gorea
Characterisation Of Some Clays Used For Whiteware Ceramics I. Mineralogical Composition, Marcel Benea, Maria Gorea
Studia UBB Geologia
In order to obtain a semiquantitative mineralogical composition of raw materials used for whiteware ceramics, four different clay types were analysed by X-ray diffraction. Studies were carried out by using a combination of analyses of the bulk sample, and of the fine fraction. Using a well-established pre-treatment methodology (use of chemicals, ultrasonic treatment, dispersion procedures), clay mineral concentration by centrifugation and sedimentation, oriented and random powder preparation, cation saturation, expansion/dehydration methods, 12 X-ray diffractometer traces were obtained from each sample. Based on these informations it was possible to establish the qualitative mineralogical composition, and also a semiquantitative one using peak …
Late Quaternary Palaeoclimate Reconstruction Based On Clay Minerals Assemblage From Preluca Tiganului (Gutai Mountains, Romania), Lucreția Ghergari, Bogdan P. Onac
Late Quaternary Palaeoclimate Reconstruction Based On Clay Minerals Assemblage From Preluca Tiganului (Gutai Mountains, Romania), Lucreția Ghergari, Bogdan P. Onac
Studia UBB Geologia
Several core samples were extracted from the overgrown crater lake of Preluca Tiganului, NW Romania. The overall lithology and the mineral assemblages (mostly clay) described from different levels within these cores, suggest three main periods having humid or dry conditions. Based on these findings, palaeoclimate conditions can be reconstructed the over the time period spanning 15,000 to 13,500 cal. years BP.
Date Noi Privind Compozitia Mineralogica A Siltului Lutitic De La Dumbrava, Judetul Cluj (New Mineralogical Data On The Clayey Silt From Dumbrava (Cluj County), Lucreția Ghergari, Corina Ionescu, Cristina Mariș
Date Noi Privind Compozitia Mineralogica A Siltului Lutitic De La Dumbrava, Judetul Cluj (New Mineralogical Data On The Clayey Silt From Dumbrava (Cluj County), Lucreția Ghergari, Corina Ionescu, Cristina Mariș
Studia UBB Geologia
New Mineralogical Data on the Clayey Silt from Dumbrava (Cluj County). New mineralogical data on the lutitic silt occurrence from the Dumbrava (Cluj County, Romania), based on TEM and X-ray diffraction studies, are presented in the paper. Mainly kaolinite, and subordinately illite and illite/montmorillonite represent the mineralogical compounds of the clayey fraction of the rock. The lutitic silt represents a local facies, sedimented in subaquatic environments (a small lake or pool) after a short-distance transport from the sources. The source for the brown clays was probably a paleosoil formed nearby magmatic rocks. The source for the light coloured clays (creamy …