Figure F5. Representative examples of X-ray diffractograms. A. Typical result for <2-µm oriented aggregate with identification of major peaks. Ratio of intensity at low angle "saddle" to intensity of 16-Å peak can be used as a measure of expandability (Rettke, 1981). Percent illite in I/S clay also can be calculated using the d-value of I(002)/S(003) reflection (Reynolds and Hower, 1970). * = Used to calculate relative abundance of clay minerals. ** = Used to calculate percent illite in mixed-layer I/S clay. *** = Used to correct peak positions. B. Results before and after treatment with HCl to dissolve chlorite. C. Display of smectite (060) peak. The d(060) values were corrected using the reference patterns for quartz (112) and quartz (211).

Figure F5. Representative examples of X-ray diffractograms. A. Typical result for <2-µm oriented aggregate with identification of major peaks. Ratio of intensity at low angle "saddle" to intensity of 16-Å peak can be used as a measure of expandability (Rettke, 1981). Percent illite in I/S clay also can be calculated using the d-value of I(002)/S(003) reflection (Reynolds and Hower, 1970). * = Used to calculate relative abundance of clay minerals. ** = Used to calculate percent illite in mixed-layer I/S clay. *** = Used to correct peak positions. B. Results before and after treatment with HCl to dissolve chlorite. C. Display of smectite (060) peak. The d(060) values were corrected using the reference patterns for quartz (112) and quartz (211).