This earthcache is located in Franconia Notch State Park in New Hampshire. No parking sticker or fees are required to enter the park.
Melting ice during the glacial retreat of the North American ice sheet over 25,000 years ago generated huge torrents of meltwater. Meltwater streams flowing on top of the ice would frequently plunge through a hole and impact the underlying bedrock, creating a giant kettle. This meltwater contained large amounts of small rock sediment which would produce extensive abrasion of the underlying rock. Thus, the kettle would become smoothed by the small stones and sand whirling around in it.
The Basin is a classic example of one of these kettles created along the Pemigewasset River in the heart of Franconia Notch State Park at the base of a beautiful waterfall. It is composed of granite, with a diameter spanning 30 feet and a depth of over 15 feet. The Basin continues to be smoothed by the small particles of stone and sand whirled around by the Pemigewasset River. Below the Basin is “Old Man’s Foot”, a distinctively shaped rock formation, which is also the natural result of the Pemigewasset River’s erosive energy.
To receive credit for this earthcache, send the answers to the following questions to my Geocaching profile:
- Describe the color and texture of the rock that is at the bottom of the Basin. What type of rock is this? On a scale of 1-10 with 10 being the hardest, what do you think is the hardness of this rock? Why?
- Describe the clarity of the water. Why do you think it has this clarity?
- Do you think the diameter of the Basin will continue to grow wider or stay the same? Explain why.