The presence of interstratified minerals in some of the studied clays
(Group 1 samples and AR1 sample of Group 3) is indicated by either the
presence, in their diffraction patterns, of an ancillary low-angle tail,
shoulder or minor peak, or separate 10 and 17 Å peaks. In order to estimate
the nature of these phases, we simulated the XRD patterns of the
two samples of the Group 3 (AR1 and AR7), in which the clay fraction
was significant (e.g. N10%) and the reflection was better developed,