Figure F5. Total formula Al content of phyllosilicates vs. depth. Formulas calculated as chlorites (total layer charge = 56; all Fe as Fe2+). Smectites include saponite, nontronite, and Mg montmorillonite. Note the absence of smectite below ~1300 mbsf (see "Phyllosilicate Mineralogy," p. 4, in "Results" for discussion).

Figure F5. Total formula Al content of phyllosilicates vs. depth. Formulas calculated as chlorites (total layer charge = 56; all Fe as Fe²⁺). Smectites include saponite, nontronite, and Mg montmorillonite. Note the absence of smectite below ~1300 mbsf (see "Phyllosilicate Mineralogy" in "Results" for discussion).