Blue Lake Varves

(a) Thin section photomicrograph from core A-99 showing the fine laminations characteristic of the varved sediments during the Little Ice Age. The lighter layers are the clay caps that overlie the darker silty portion of the varves. (b) High-resolution digital photograph of surface core D-06 showing the same interval represented by the thin section in part (a). The black line designates where the couplets were measured. (c) Image of core C-06 from the lower portion of the core (below 100 cm) where varve thickness increases. Note that the color and structure of the varves are the same as in (a) and (b), only thicker