Figure F6. Hardground marking the top of Unit VI (114-117.5 cm). The hardground is mineralized, and the burrow gallery at 119-120 cm was empty at the time of hardground formation, as seen by the mineralized and bored underside of the hardened layer at 119 cm. The 2-mm-long boring in the lower right (119.2 cm) is clearly visible due to the white burrow fill. The upper surface of the hardground is also bored, notably to the upper left. A 1- to 2-mm-wide crack, filled with sediment from above, extends obliquely downward from the top of the hardground. It is a Neptunian dike (interval 182-1132C-31R-105-120).