Figure F1 illustrates the <2-µm talc normalized peak areas of smectite, illite, kaolinite, chlorite, quartz, plagioclase, and calcite of sediments recovered from Site 1146 (Table T1). Illite, chlorite, quartz, and plagioclase concentrations steadily decrease with increasing depth through Unit I. Kaolinite and calcite concentrations increase with depth, whereas smectite values are constant in this unit. Illite, quartz, and plagioclase show relatively high variability in this unit compared with the underlying sediments. Unit II demonstrates much more uniform sediment composition, with illite, chlorite, and quartz concentrations remaining relatively constant throughout the unit. Kaolinite concentration increases with depth, following a drop in concentration across the Unit I/II boundary. Plagioclase concentration shows a small but steady decrease throughout this unit. Smectite concentration does not change across the Unit I/II boundary, decreases to a steady low value from 310 to 400 mcd, and increases again toward the bottom of Unit II. Calcite concentrations are highest between 250 and 300 mcd, followed by a steady decrease toward the bottom of the unit.
Figure F2 illustrates the <2-µm talc normalized peak areas expressed on a calcite-normalized basis to correct for any calcite dilution effects on the terrigenous mineral concentrations (Table T2). None of the mineral concentration trends described above are significantly changed by this normalization; however, there is a slight increase in the concentration of most mineral phases over the interval of highest calcite concentration (250-300 mcd).
Figure F3 illustrates some mineral ratios for the <2-µm sediments (Table T3). The illite/quartz and chlorite/quartz ratios are essentially constant throughout the interval investigated. The smectite/quartz ratio indicates intervals of relatively higher smectite concentrations from 240 to 290 mcd and below 400 mcd. Kaolinite/quartz increases from Unit I through the upper 20 m of Unit II, is relatively low from 275 to 325 mcd, and is a constant high concentration through the remainder of the interval studied. The kaolinite/chlorite ratio increases with depth in Unit I, is constant in the upper part of Unit II, and is high below 400 mcd.