TEXTURAL AND MICROANALYSIS OF IGNEOUS ROCKS: TOOLS ...

Figure 2.9. Trace element ratio plots for parent magmas of OJP plagioclase
phenocrysts and xenolith plagioclase crystals. Error bars represent the total
potential error obtained by combining the uncertainty of LA-ICP-MS
measurements and that inherent in calculating the partition coefficients (D)
using uncertainties reported in Bindeman et al. [7] using standard error
propagation. Fields defined by published OJP whole-rock basalt data are
displayed [46, 133]. A) Ti vs Mg # [Mg + (Mg+Fe)] data show no distinct
differences between xenolith crystals and phenocrysts, except that An-rich
crystals tend to have lower Ti and trend to greater Mg#; B) Sr/Ti vs. La/Y:
note phenocryst parent magmas extend to higher La/Y ratios than higher
An xenolith crystals; C) La/Y vs. Ba/Sr: vectors defined by clinopyroxene
and plagioclase crystallization of relatively primitive Kroenke basalt are
shown as labeled arrows. For illustrative purposes, the head of the arrow on
the clinopyroxene vector corresponds to a crystallinity of ∼70%; D) La/Y vs.
Eu and vectors defined by clinopyroxene and plagioclase crystallization of
relatively primitive Kroenke basalt. Again, the head of the arrow on the
clinopyroxene vector corresponds to a crystallinity of ∼70%. Parent magmas
of xenolith crystals and phenocrysts from Site 1183 Unit 7 extend to lower
Eu and La/Y.
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