Emerald Bog: The Oldest Peat in the Catskills

by Michael Kudish

In 1994, I had an idea. Workers in other regions were using macrofossils (needles, leaves, cones, twigs, wood, bark, roots, seeds, fruits, etc.) preserved in bog peat and/or lake sediments to reconstruct the vegetational history of their regions… Could I possibly do that in the Catskills?

Since 1995, I have studied 111 bogs. Previously, the oldest peat samples were from the bottoms of two Catskill bogs tied for first place at about 14150 years. That record held until 2016.


On May 21, 2016, I was invited to Mountain Top Arboretum to speak about the 14000-year history and ecology of hemlock in the Catskills. I noticed Emerald Bog on the Arboretum's brochure map. I had to investigate. So with two assistants, Director Joan Kutcher, and Elizabeth Petty, we exhumed peat samples from two different depths in the bog.

Removing the macrofossils from the peat and identifying them is a time-consuming, painstaking job, so only a preliminary look has been made. It is the radiocarbon date on the deepest sample at 341 centimeters (135 inches) that broke the previous record: about 14900 years! Radiocarbon dating materials that old is somewhat inexact, so the peat could be anywhere between 14700 and 15100 years – still a record by far.

The oldest peat samples from Emerald are very silty and gravelly, informing us that the bog basin was once an open pond, filling in with mineral deposits washing off the freshly-exposed surrounding glacial till upland shortly after the ice sheet melted. The forest had not yet moved in so there were nil tree roots to prevent erosion. The pond continued to accumulate silt for probably several centuries and had aquatic plants – water naiad and pondweed – growing in it. I have saved their seeds.

The silting stopped shortly after the forest migrated in from the south and surrounded the pond. Tree parts of red spruce, balsam fir, eastern hemlock, and yellow birch began to fall in. These four species are still dominant around and in the bog today – showing hardly any change in the forest in about 14000 to 13000 years.

Another peat sample, taken at a depth of 118 centimeters (46 inches), dated to 11650 years. By this time, the aquatic plants were gone. The pond had fully filled in with forest.

Many paleoecologist and geologist colleagues have asked me when the ice sheet retreated from the Catskills. We now know, because of Emerald Bog's record age, that we were already free of ice about 14900 years ago.

For a more complete Emerald history, we need to return to the bog and obtain a FULL core peat sample from bottom to top, identify the macrofossils, and have subsamples radiocarbon-dated at frequent intervals up and down the peat core. Anyone want to try?