Catskills 📍

I was fascinated by this post on Glacial Lake Windham by the Catskill Geologist and thought it would be ineresting to pull the LIDAR of the area.

Let’s learn some more this week. We would like you to drive west from Windham on Rte. 23. You may have done this before, perhaps many times. But, as always, we want you to be paying more attention to the landscape that you are passing. We, especially, want you to take heed of the flat landscapes down at the bottom of the valley. It would be easy to dismiss this as a floodplain, after all valley floors are supposed to display floodplains. But, you would be wrong; this flat landscape is the floor of an ice age lake. Lake deposits are almost always spread out as flat sheets. That’s what we see here.

These lake bottom landscapes continue at least as far west as Ashland. They speak to us of a glacial lake. It was a big one, extending at least five miles from the Windham moraine to a bit west of Ashland. Rte. 23 lies on a platform that runs parallel to the old lake. That platform also has an ice age origin. It is composed of sediments that were dropped down the northern valley wall and deposited as a lakeshore deposit called a glacial terrace. That terrace was irresistible to highway engineers when they were making Rte. 23. It lifted the highway up onto a well-drained surface.