I timed this fieldwork to coincide with a Sierra Club project: all week a group of Sierra Club members volunteered in Acadia. On Tuesday, they joined me and the BEAST lab as we hauled coring equipment — including giant inflatable pontoons and two 4x8’ plywood deck pieces — up to Sargent Mountain Pond. We carried in giant inflatable pontoons for a raft and two 4x8’ plywood decks: a major feat on a challenging trail. We hiked it all in, assembled the raft and inflated a kayak, and then launched our floating field site on to the pond. From our raft, we extracted cores of sediment from the deepest basin of the pond — over 11 feet deep — using a piston corer. The piston corer allows us to push deep into the lake bottom and pull up 1 m of sediment in each drive. Over the course of three days we cored nearly 9 meters of sediment. These cores represent a journey through over 4 meters of organic material under Sargent Mountain Pond, into the grey sands of a glacial landscape. We cored 4 meters deep twice: two overlapping records will give us a continuous chronicle of pollen through the last 15,000 years.
We cored Sargent Mountain Pond because it sits just below treeline in Acadia and subalpine plant communities grow at its edge. As the Laurentide ice sheet retreated, Sargent Mountain Pond emerged as the “first pond in Maine”; the rest of its limnological siblings were under still ice. Previous coring research at Sargent Mountain Pond has confirmed this and sediments in the basin are over 16,000 years old.