Figure F9. Ash layer in bioturbated chalk of Subunit IC (Oligocene; interval 192-1183-15R-1, 101-117 cm). Volcanic ash has been dispersed upward by bioturbation mixing and partially fills the underlying burrows.

Figure F9. Ash layer in bioturbated chalk of Subunit IC (Oligocene; interval 192-1183-15R-1, 101-117 cm). Volcanic ash has been dispersed upward by bioturbation mixing and partially fills the underlying burrows.