engleski

Ivošević Gaj ceramic clay deposit in the vicinity of Vojnić

Ceramic clays in the “ Ivoševićev Gaj” deposit are used by the Inker d.d. company from Zaprešić, as raw materials for ceramic tiles, and to lesser extent, the production of sanitary ceramics. Ceramic clays interlayered by Pliocene-Pleistocene gravels, sands and silts, whose overlie the Middle to Upper Triassic dolomites with erosional contact. Ceramic clays occur as larger or smaller discrete lenses in several levels with an average thickness of 3.2 - 3.9 m. Their chemical composition expressed in weight % is: SiO2 (69– 79) and Al2O3 (14– 28). The lower values have the other oxides (Fe2O3, TiO2, CaO, MgO, K2O, Na2O). The values are from 0, 1 to 3, 3%. According to the results of mineralogical investigations (of the clay minerals), kaolinite (15-28%) and illite (10-20%) present in concentrations are more abundant than montmorillonite (10%). The geological column Katinovac– 1 is situate in the western part of the “ Ivoševićev Gaj” ceramic clay deposit. Sediments within the column comprise three facies: Facies of massive clays, Facies of sands with gravel lenses and Facies association A. Lithostratigraphically these layers belong Pliocene - Pleistocene “ Bistra formation” . The Facies of Massive clays (raw materials for explotation) was observed in the lower part of the column as well as in the upper part as two intercalations. Clays were deposited from suspension in stagnant water. The association with other facies, together with the observed palinomorphs and lignohumin remains, indicates that these sediments were most probably deposited in oxbow lakes and flood plains of fluvial environments. The Facies of sands with gravel lenses occurs in the lower part and in the upper part of the column. These sediments have the main characteristics of alluvial channel environments as result of river bank collapse with a short term of flood plain ecology. Facies association A is present in the upper part of the column. Sediments are composed of a succession of small fining-upward cycles, which generally contain gravel, sand and clay. Fining-upward cycles suggest current speed decrease, occasional channel abandonment and formation of short-term flood plains. The sedimentary succession within the Katinovac– 1 column, beginning with a flood plain environment and finishing with the development of channel sediments, generally show coarsening-upward tendency and suggests progradation of a river system.

Gaj; ceramic clay; deposit; Vojnić; Pliocene-Pleistocene

nije evidentirano