Figure F18. Multichannel seismic reflection profile (MAR13) showing the location of Site 1193 and basement reflection (dashed lines). Shown are examples of thin sections of altered olivine basalts that comprise basement in this region. A. Thin section view showing the products of alteration (zeolites-natrolites) infilling an amygdaloid under cross-polarized light. B. Thin section view under normal light showing the "ghost" residuals of plagioclase lathes and pyroxenes. C. Thin section view under cross-polarized light showing the "ghost" residuals of plagioclase lathes and pyroxenes. D. Magnetic inclination data from recovered basalts.