Figure F11. Close-up photograph of some of the volcanic glass-rich layers constituting Horizon A at the boundary between lithostratigraphic Subunits IIIA and IIIB. A. Last occurrence of volcanic glass (interval 204-1250C-19X-7, 5-23 cm). B. Thick volcanic glass-rich layer (interval 204-1250F-10X-4, 0-10 cm).

Figure F11. Close-up photograph of some of the volcanic glass-rich layers constituting Horizon A at the boundary between lithostratigraphic Subunits IIIA and IIIB. A. Last occurrence of volcanic glass (interval 204-1250C-19X-7, 5-23 cm). B. Thick volcanic glass-rich layer (interval 204-1250F-10X-4, 0-10 cm).