Figure F17. Photomicrographs showing titanomagnetite morphologies. A. Alteration of titanomagnetite to maghemite along cleavage planes and around rims in the weathered flow top of Unit 10 (Sample 197-1205A-24R-2 [Piece 19, 124-130 cm]) (reflected light; f

Figure F17. Photomicrographs showing titanomagnetite morphologies. O, P. Early stages of maghemite (bright blue-gray) replacement of titanomagnetite (dull pink-gray) in the Site 1205 basement lava units (reflected light; field of view = 0.25 mm): (O)maghemite development around the rim of and along a fracture in titanomagnetite in Subunit 26a; ilmenite oxidation lamellae are also evident (Sample 197-1205A-41R-5 [Piece 1A, 24-26 cm]) (photomicrograph 1205A-267). (P) maghemite development along titanomagnetite cleavage planes in Unit 27; one titanomagnetite crystal is unaltered (Sample 197-1205A-43R-2, 58-60 cm) (photomicrograph 1205A-254).