We did a short hike to the Glacial Erratic at Rockefeller State Park Preserve (ny.gov)in Pleasantville, New York in Westchester County in the afternoon of Sunday September 15th. The granite rock is tilted 90 degrees from how it was originally metamorphosed deep beneath the Earth’s surface. There are white veins of lower meting po9int quartz that separated out during metamorphosis. 600 million years old. This mass of free-standing gneiss, almost 20 feet high and 65 feet in circumference, is probably the largest ”glacial erratic” to be found anywhere in the county. The glacier that transported the glacial erratic to Rockefeller State Park Preserve was part of the Late Wisconsin glaciation, which occurred approximately 20,000 to 25,000 years ago.
The activates look interesting. Maybe I’ll get a chance to try one or two.