Figure F4. Photomicrograph, with crossed polars, of Sample 187-1162A-5R-1 (Piece 15, 73-75 cm; see "Site 1162 Thin Sections"), showing part of a plagioclase glomerocryst in altered metabasalt. One original crystal (occupying most of the field of view) is now four separate grains. Oscillatory zoning can still be seen within the three grains that make up the top left of the field of view, but these grains have different extinction angles. The dark area (top left) is clay replacing olivine.