Charakterystyka mineralogiczna dolnotriasowych surowców ilastych ze Skoków (Góry Świętokrzyskie)

Abstract

Kompleks skał ilastych z rejonu Skoków reprezentowany jest przez wiśniowe mułowce i iłowce, odpowiadające serii hieroglifowo-pseudooolitowej pstrego piaskowca środkowego. W składzie mineralnym dominują minerały ilaste: illit, kaolinit, klinochlor i minerał mieszanopakietowy iIlit-smektyt. W zmiennych proporcjach występują: kwarc, hematyt. getyt, gips i kalcyt. Pod względem ceramicznym surowce te można wykorzystać w przemyśle ceramiki budowlanej do wyrobów grubo-i cienkościennych oraz drążonych. a także do produkcji wyrobów o czerepie spieczonym typu klinkierowego lub kamionkowego.MINERALOGICAL CHARACTERISTICS OF LOWER TRIASSIC CLAY RAW MATERIALS FROM THE SKOKI AREA (GÓRY SWIĘTOKRZYSKIE MTS) The paper presents the results of studies on mineral composition of cherry-red claystones and siltstones of Middle Buntsandstein hieroglyph-pseudooolite series from the vicinities of Skoki (Fig. 1). Ten core samples from 2 boreholes were studied in detail (Table 1). Table 2 shows results of granulometric analysis, Table 3 - the results of qualitative and quantitative studies carried out with the use of x-ray powder analysis, Table 4 - DTA data., and Tables 5 and 6 - chemical composition of rock samples and separated fractions below 2 μm. The share of clay minerals in the studied rocks was found to be close to 50% llIite clearly predominates among clay minerals (about 60 - 70%), being accompanied by kaolinite, clinochlore, mixed-layer illite-smectite mineral and smectite of the beidellite-nontronite series (sample R-41). Clay mineral assemblage of the iIIite-clinochlore-mixed layer illite-smectite mineral type occurs in lower part of the clay rock sequence, and that of the iIIite-kaolinite-chlorite-type - in its top part. Content of clinochlore increases in basal layers of the sequence, resulting in their enrichment in MgO, whereas content of kaolinite slightly decreases in top parts. Other minerals present here include quartz, finely-dispersional hematite and goethite. There were also identified plagioclases, gypsum and calcite. The studies involved basic tests of rocks as potential raw materials for ceramic industry (Tables 7 - 8). The rocks were found to match requirements for material for producing thick- and thin-walled and hollow products in the range of porous material. They may be also used for producing articles with kilned body of the stoneware and klinkier types.