Figure F73. Chemical stratigraphy of Hole 735B from 500 to 1508 mbsf, based on the composition of gabbros with <1 wt% TiO₂. The troctolitic samples recovered between 500 and 520 mbsf belong to lithologic Unit VI defined by the Leg 118 shipboard party. The boundaries between successive units are based solely on abrupt changes in chemical composition except for the boundary at 800 mbsf. However, the boundaries also coincide with changes in lithologic, alteration, and structural properties. Symbols are as in Figure F64.