Previous   |   Close   |   Next

Figure F27. Photomicrographs of variation of exsolution and dissolution of groundmass titanomagnetite with depth, Hole U1349A. A. Skeletal titanomagnetite with fine ilmenite exsolution lamellae (right) next to spinel in olivine that has reticulate alteration on two sides but is unaltered within the rim of the olivine and has a titanomagnetite rim with exsolution lamellae; 168.05 mbsf (Thin Section 210; Sample 324-U1349A-7R-3, 111–113 cm). B. Unusually broad ilmenite exsolution lamellae in an altered titanomagnetite; 166.25 mbsf (Thin Section 208; Sample 324-U1349A-7R-2, 78–81 cm). C. Spongy titanomagnetite with some exsolution features, but which is mainly irregularly dissolved around the crystal; 186.84 mbsf (Thin Section 222; Sample 324-U1349A-13R-3, 97–99 cm). D. Well-formed skeletal titanomagnetite with a gridwork of exsolution lamellae in three different shades of gray; 205.05 mbsf (Thin Section 234; Sample 324-U1349A-12R-2, 111–113 cm). E. Titanomagnetite that has been almost completely eaten away, presumably leaving mainly a gridwork of ilmenite exsolution lamellae as the skeletal backbones of the crystals; 215.65 mbsf (Thin Section 241; Sample 324-U1349A-13R-3, 69–72 cm). Oil immersion and reflected light.

Previous   |   Close   |   Next  |   Top of page