The most recent glacial episode in Maine began about 25,000 years ago, when the Laurentide ice sheet overspread New England. During its peak development, this ice sheet was centered over eastern Canada and flowed east to southeast across Maine. It became several thousand feet thick and covered the highest mountains in the state. Climatic warming forced the Laurentide ice sheet to start receding as early as 21,000 years ago, soon after it reached its terminal position on Long Island, New York. The ice margin also withdrew from the continental shelf east of Long Island and reached the present position of the Maine coast by 15,000 to 14,000 years ago. By 12,000 years ago the glacier had shrunk to a local ice cap covering northern Maine and parts of neighboring Quebec and New Brunswick. This local ice mass had been cut off from the principal Laurentide ice sheet in Canada by encroachment of the sea up the St. Lawrence River valley. The residual ice cap developed a new flow pattern such that ice in northernmost Maine actually flowed back toward Canada! The last remnants of glacial ice probably were gone from Maine by 10,000 years ago.
In this area there is evidence that the glacial ice sheet slowed and stopped for a period of time before it finally retreated forming this kame field and its associated kettles. The thickness of the glacial deposition in this area is about sixty feet of sand and gravel. A kame is mound-like hill of poorly sorted drift, mostly sand and gravel, deposited at or near the terminus of a glacier. It is generally believed that a kame may be produced either as a delta of a meltwater stream or as an accumulation of debris let down onto the ground surface by the melting glacier. A group of closely associated kames is called a kame field and can be interspersed with kettle holes.
A kettle hole is formed by blocks of ice that are separated from the main glacier - perhaps the ice front stagnated or retreated or perhaps ice blocks were washed out from the glacier during a glacier flood. If conditions are right, the isolated blocks of ice then become partially or wholly buried in outwash till. When the ice blocks eventually melt they leave behind holes or depressions that fill with water to become kettle hole lakes. The name derives from an old meaning of 'kettle', as in a deep iron basin for heating water over a fire. A 'kettle drum' has a similar derivation.
These kettle holes dot the landscape in this area. Ones that are filled with water are characterized by not only their shape but the fact that they often do not have either inlets or outlets. In the areas surrounding these small pond you will find very sandy soil that once covered the ice block. As you look at these holes it is hard to imagine the size of the ice block that once fill these holes. But looking at the shape of the ponds and around the edges you can see where the ice block that was once covered with till formed deposits along the edge of the pond in this area. The glacier was moving in a southeast direction before it stopped to form these ponds.
To log this Earthcache: Send an email to me through my profile with the following information: At Waypoint #1 when you look at kettle holes on both sides of the road describe how they differ or at final coordinates describe how the texture of the soil on the beech and the gravel cut 50 meters to the southeast differ. They were deposited in different manners. Please begin your email with the name of the earthcache and make sure your log includes the number of people in your group. It also would be nice if you would post a photo so others would know what they have to look forward to at this earth cache.
If you enjoy this earthcache you may want to check the Maine Geological Survey located at http://www.youtube.com/watch?v=OK8VDsPKz5E&feature=relmfu They have developed a number of information sheets or field localities giving a great deal of information about geologic features. They also have a number of books and maps about Maine’s natural history/ geology that you might find interesting.