Figure F14. Site 1262 lithostratigraphic composite illustrating downhole variation in magnetic susceptibility (MS), natural gamma radiation (NGR), carbonate content, and color reflectance (L*, lightness). Major lithologic unit boundaries coincide with step changes in these parameters. MS and NGR variations largely correlate with clay and volcaniclastic content. The P/E and K/P boundaries are distinct from adjacent sediments in their MS and NGR values as they represent intervals of decreased carbonate deposition/preservation and increased clay and volcanic ash accumulation, both of which produce distinctive increases in MS and NGR. A single value reached 625 on the MS scale as indicated in the figure.
Next Figure | Table of Contents