Figure 4. Photographs of gypsum cycles in Holes 975B and 975C. Thin-section sample intervals are marked with black shading to right of scale. A. Section 161-975B-34X-2, 0-32 cm. Contact between gypsum cycles 1 and 2 (as defined in Figure 2) is at 28 cm. Components of gypsum cycle 2: thin clay bed (25-28 cm), laminated to thinly bedded gypsiferous chalk (8-25 cm), and planar-laminated gypsum (0-8 cm; note few planar-wavy laminae at 3 and 5.5 cm). Components of gypsum cycle 1: nodular gypsum (28-30 cm) and planar-laminated gypsum (30-32 cm; note planar-cumulus lamina at 31 cm). B. Section 161-975C-34X-1, 46-72 cm. Contact between gypsum cycles 1 and 2 (as defined in Figure 2) is at 69 cm. Components of gypsum cycle 2: thin clay bed (66.5-69 cm), laminated to thinly bedded gypsiferous chalk (48-66.5 cm), and planar-laminated gypsum (46-48 cm). Components of gypsum cycle 1: nodular gypsum (69-71 cm), and planar-laminated gypsum (71-72 cm).

Figure 4. Photographs of gypsum cycles in Holes 975B and 975C. Thin-section sample intervals are marked with black shading to right of scale. A. Section 161-975B-34X-2, 0-32 cm. Contact between gypsum cycles 1 and 2 (as defined in Figure 2) is at 28 cm. Components of gypsum cycle 2: thin clay bed (25-28 cm), laminated to thinly bedded gypsiferous chalk (8-25 cm), and planar-laminated gypsum (0-8 cm; note few planar-wavy laminae at 3 and 5.5 cm). Components of gypsum cycle 1: nodular gypsum (28-30 cm) and planar-laminated gypsum (30-32 cm; note planar-cumulus lamina at 31 cm). B. Section 161-975C-34X-1, 46-72 cm. Contact between gypsum cycles 1 and 2 (as defined in Figure 2) is at 69 cm. Components of gypsum cycle 2: thin clay bed (66.5-69 cm), laminated to thinly bedded gypsiferous chalk (48-66.5 cm), and planar-laminated gypsum (46-48 cm). Components of gypsum cycle 1: nodular gypsum (69-71 cm), and planar-laminated gypsum (71-72 cm).