Fig. 33. Carlsbad- and albite-twinned plagioclase (dark gray and light tan; center) is penetrated and replaced by K-feldspar (light gray; upper right). K-feldspar (light gray; upper left) also replaces biotite (brown, left side), leaving remnant shreds of biotite in the K-feldspar. Wartlike myrmekite (top and bottom) occurs locally along borders of the plagioclase against K-feldspar. From same thin section as in Fig. 32.