Figure F10. Composite digital photographs of the middle/upper Eocene boundary "pentachert" interval of Site 1218 plotted vs. gamma ray attenuation (GRA) bulk density in Sections 199-1218A-25X-1 and 25X-2, 199-1218B-25X-1, and 199-1218C-18X-3 and 18X-4. Five chert layers in chalks were recovered intact and can be observed through all holes drilled at Site 1218. The contacts of the radiolarite of Unit III and these lithified chert layers are gradational. More of these intact chert layers were observed in Cores 199-1218A-27X and 199-1218C-18X, 19X, and 20X.

Figure F10. Composite digital photographs of the middle/upper Eocene boundary "pentachert" interval of Site 1218 plotted vs. gamma ray attenuation (GRA) bulk density in Sections 199-1218A-25X-1 and 25X-2, 199-1218B-25X-1, and 199-1218C-18X-3 and 18X-4. Five chert layers in chalks were recovered intact and can be observed through all holes drilled at Site 1218. The contacts of the radiolarite of Unit III and these lithified chert layers are gradational. More of these intact chert layers were observed in Cores 199-1218A-27X and 199-1218C-18X, 19X, and 20X.