A New Method for Clay Mineral Analysis and Its Application in Geology

X-ray diffraction (XRD) peaks in a low-angle diffraction section of clay minerals, especially those ofauthigenic origin, have broadening and tailing features in shape. Using the five basic parameters, peak position, peakheight, width, shape coefficient and asymmetry, to describe an XRD peak is more accurate, comprehensive and integratedthan using only 3 of them, position, height and width. Following the concept of the five basic parameters of an XRD peak,the program Decoform proposed in this study provides more information in mineralogical analyses by fitting actual XRDprofiles. In combination with the HW-IR plot, Decoform can be systematically and accurately used in the comprehensiveanalyses of crystallinity, domain size, lattice strain and quantitative phase. It is also of value for the geologicalinvestigations of diagenesis, metamorphism, basin maturity, structural stress field and so on.