Figure F7. A. Mineral mass proportions (e.g., represented by cpx#) do not correlate with mineral compositions (e.g., represented by whole-rock Mg#) in gabbroic rocks. B. The apparent correlation of whole-rock Ca#, which is often used to reflect mineral compositional variation only (e.g., as in plagioclase), with cpx# is in fact also controlled by mineral modes because Ca is dominated by clinopyroxene (cpx), whereas Na is dominated by plagioclase (plag) in the whole rock. Symbols are as in Figure F3, p. 20.

Figure F7. A. Mineral mass proportions (e.g., represented by cpx#) do not correlate with mineral compositions (e.g., represented by whole-rock Mg#) in gabbroic rocks. B. The apparent correlation of whole-rock Ca#, which is often used to reflect mineral compositional variation only (e.g., as in plagioclase), with cpx# is in fact also controlled by mineral modes because Ca is dominated by clinopyroxene (cpx), whereas Na is dominated by plagioclase (plag) in the whole rock. Symbols are as in Figure F3.