Cores from the CAM-DOR and SDB sites were sampled at approximately 1ft (0.30 m)
intervals after spot sampling was done to detect intervals barren of diatoms. Samples were
initially prepared as smear slides, using a small amount of sediment mounted with Norland
optical adhesive. This method, though not useful for statistical analysis, can highlight diatombearing
sections suitable for more refined treatment of strewn samples. After an initial
reconnaissance of the samples via light microscopy, diatom-bearing intervals with suitable
marker species were identified and assigned approximate ages based on the revised diatom
zonation of Andrews (1988).