Figure F19. Multichannel seismic reflection profile (MAR07) showing the location of Site 1198 and basement reflection (dashed line). Shown are examples of thin sections of altered olivine basalts that comprise basement in this region. A. Thin section view under cross-polarized light showing the groundmass, olivine phenocrysts and plagioclase lathes. B. View of altered plagioclase phenocrysts under cross-polarized light showing olivine phenocrysts and plagioclase lathes. C. Thin section view showing the products of alteration (quartz) infilling an amygdaloid under cross-polarized light. D. Magnetic inclination of recovered basalts.