Figure F7. Photomicrograph in plane-polarized light of Sample 187-1162B-3R-1 (Piece 22, 116-120 cm; see "Site 1162 Thin Sections"), a dolomite-cemented basalt breccia. An altered basaltic clast (bottom) has a chilled margin that has been replaced by brown palagonite (P, top of clast). Dolomite crystals along the edge of the clast are larger and elongate perpendicular to the clast; these larger crystals have fewer impurities than those farther into the matrix. This can be seen as a clear rim in hand specimen.