Figure F49. Extensively altered felsic vein in Sample 176-735B-160R-6 (Piece 6, 118-134 cm). Plagioclase is highly altered to secondary plagioclase, prehnite(?), and zeolite. Clinopyroxene is pervasively replaced by amphibole and chlorite. This vein also contains biotite, apatite, and trace amounts of quartz; magnetite is common along the vein margins, both in the vein and wall rock.