DIAGENETIC TRANSFORMATION OF CLAY MINERALS IN LOWER CAMBRIAN ARGILLACEOUS SEDIMENTS OF NORTH ESTONIA

Abstract

. Clay mineral diagenesis in the Lower Cambrian sediments of the Lontova and Liikati formations in North Estonia, accompanying the main process of illite neoformation, was studied by means of X-ray powder diffraction. Fe-rich chlorite as well as microcrystalline quartz are typically diagenetic byproducts in the clay fraction, formed during illitization. Higher contents of kaolinite and of very fine clay subfraction (< 0.06 pm), consisting of only diagenetically formed minerals, in the silty sediments ofthe Liikati Formation are probably a result of meteoric water influx.