Figure F147. A. Backscatter SEM image of amphiboles replacing clinopyroxene in diabase (Sample 304-U1309D-16R-2, 58–61 cm). For electron microprobe data, see Table T9. Anorthite (An) content of plagioclase (Plag) is marked on the photo. Amphibole compositions are ferroactinolite at A, fluorine-rich ferroedenite at B, and magnesiohornblende at C. B. Complex zoning in secondary amphibole replacing clinopyroxene (Cpx). Note that the cleavage traces show that this is a single crystal. No electron microprobe data are available from this area, but the main reason for contrast is probably variations in Fe/Mg ratio. The complex truncated zoning suggests generation of open porosity during reaction. (Photographs taken by Eric Condliffe, Leeds University.)
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