INTERSTRAT - AN EXPERT-SYSTEM TO HELP IDENTIFY INTERSTRATIFIED CLAY-MINERALS FROM POWDER XRD DATA .1. DESCRIPTION OF THE PROGRAM

The INTERSTRAT program has been specifically designed to aid the geolo gist in the identification of the phyllosilicates from powder XRD data . The program achieves this by comparing the experimental 001 d-spacin gs with a knowledge base of diffraction parameters; a set of likely so lutions is then displayed. The method employed by INTERSTRAT is analog ous to that used by the clay mineralogist whereby the clays are initia lly identified down to the group level from the d(001) data alone. Thi s procedure also utilises the d-spacings collected from clays that hav e been subjected to standard clay mineral treatments, i.e. glycolation and heating to 300 degrees and 500 degrees C. One of the most importa nt features of INTERSTRAT is its knowledge base of d-spacings for the interstratified clay minerals in which calculated d(001) spacings for an individual mixed-layer clay are recorded with respect to its Reichw eite, the state under which the d-spacings were collected and the perc entage of the mixed-layer components.