Frequently Asked Questions
How accessible is Polar Caves?
Our animal area is accessible .
Strollers, baby-back carriers?
But I wear Flip-flops year-round….
Are the caves cold?
But it is Raining…
How long should I plan to be there?
Why is it called Polar Caves?
What is “Dog Parking”?
When is the best time of day to visit?
Interested in the Geology?
Geology of Polar Caves
Located on Route 25, 4-miles west of Plymouth, NH
Francis Haley, B.S., M. S, Head of Department of Geology, Tyler College
and Mark T. Sylvester, B. Ed. M. Ed., Science Department
Plymouth State College
The geology of the Polar Caves began during Paleozoic Era of geologic time, 200 to 300 million years ago. During that Era, hot molten masses, magma, from deep within the earth were squeezed upward into the overlying earlier deposited sea sediments where they slowly cooled underground and solidified into what are today’s widespread granite of New Hampshire.
During the 200 million years which followed the intrusion of the granite, weathering and erosion removed thousands of feet of the overlaying sediments, eventually exposing the large bodies of granite until they became high mountains. The essential features of the Polar Caves were sculptured during that period.
About fifty thousand years ago, a great continental glacier formed in Canada and advanced slowly southward over the mountains of New Hampshire, over the site of today’s Polar Caves. The glacier thickened, reaching a height of well over a mile to cover the highest mountains and fill the deepest valleys.
Such a massive accumulation of ice in motion, though the movement was slow, had a tremendous destructive force. As the ice ground over Mt. Haycock, it plucked and quarried boulders from the lee side of the mountain, forming a cliff on that side. The top of the cliff was badly fractured and cracked by the time the glacier ceased its advance and began to melt. As the ice sheet thawed, frost action was intense. Great blocks of granite cracked and loosened. With the northward recession of the glacier, this loosened material was deposited at the base of the cliff in a jumbled mass of large granite boulders.
These massive granite blocks fell at the base of the cliff forming a series of caves and passages through which people can walk. Thus, fourteen to twenty thousand years ago the Polar Caves were formed.
Nature did not end her work with the formation of the Caves alone; she also exposed a variety of minerals embedded in the granite boulders. The principal rock type is granite and igneous rock, but there are some metamorphic to be seen, notably schist and gneisses.
There are many coarse exposures of quartz, feldspar, mica, garnet and rare deposits of beryl and limestone dissecting many of the huge granite boulders.