1. XRD INVESTIGATION OF THE CLAY FRACTION IN SOME ROMANIAN ZEOLITIC VOLCANIC TUFFS AND DIATOMITES. Authors: DANA POP, IOAN BEDELEAN, HOREA BEDELEAN.2. NEW DATA ON THE VOLCANIC TUFF FROM PETREŞTII DE JOS (CLUJ DISTRICT). Authors: HOREA BEDELEAN, IOAN IVAN, DANA POP, IOAN BEDELEAN, GHEORGHE PLEŞOIU.