Figure F3. Interlayer cation contents of smectites. Formulas calculated as smectites (total layer charge = 44; all Fe as Fe2+). Two nontronite analyses have high K content (center bottom of plot).

Figure F3. Interlayer cation contents of smectites. Formulas calculated as smectites (total layer charge = 44; all Fe as Fe²⁺). Two nontronite analyses have high K content (center bottom of plot).