Szekessy Vilmos (szerk.): A Magyar Természettudományi Múzeum évkönyve 57. (Budapest 1965)

Csalogovits, I. J.: Geological and petrological conditions of the Szanda - Bercel area

The intensity of decomposition can be summed up in the following degrees; a. The dusting, green material of chlorovulcanites discernible on the andésite block occurring in the veins. The feldspars are completely decomposed, the small augite grains of the basic material are replaced by chlorite. A similarly extreme degree of decomposition appears in the violescent-rust-red hydroandesite blocks that Fig. 6.: Different types of the decomposed andésites. 1. Original andésite. 2. Contact andésite. 3. Andésite decomposed hydrothermally. 4. Andésite decomposed by wethering Fig. 7.:Differential-thermal investigation of samples. 1. Bercel-Istenhegy: hydroandesite vein-montmorillonite-calcite. 2. Szanda: contact, clayey sand (2.4 m), clay mineral, quartz, calcite of the montmorillonite type. 3. Szanda: contact andésite (1—15 cm); no characteristic peak values are discernible. 4. Szanda: contact andésite (1.60 m), little calcite montmorillonite. 5. Szanda: contact andésite (1.8 m) ; no characteristic peak values are discernible. 6. Szanda: contact andésite (0.5 cm), montmorillonite clay mineral content, very few ferric-hydroxide minerals. 7. Bercel: andésite, very little calcite. 8. Bercel: hydrothermally decomposed andésite I, clay mineral of the montmorillonite type. 9. Bercel: hydrotermally decomposed andésite II, no characteristic peak values. 10. Bercel: hydrothermal vein material high content in clay minerals of the montmorillonite type