Lamoiners Learn Their Ice Age History

Dr. Hal Borns

On June 7, 2017 Friends of Lamoine sponsored a talk by Hal Borns, Professor Emeritus of Glacial and Ice Age Geology at the University of Maine. It was well attended, filling up our Town Hall to capacity. Video of the entire talk can be watched by clicking here.

Dr. Borns began by talking about the history of understanding about  Maine’s unique geology, beginning with the early 19th century belief that it was shaped by Noah’s flood to later evidence-based glaciology which emerged after 1850 with the theories of Swiss scholar Louis Agazziz.

He then covered the topic of esker formation and the “contact deltas” which formed at the point they reach the ocean. Lamoine’s Cousins Hill, he explained, is such a delta, and is a stop (#8) on his Ice Age Trail.

Click to enlarge.

He then showed a chart depicting the changes in temperature during and after the last period of glaciation to the present day. He pointed to a twenty-year period in which abrupt climate change occurred, a reversal of the overall warming trend in which trees were replaced by tundra. He emphasized that abrupt climate change is common in earth history and will occur again.

Click for larger view.

Returning to Lamoine’s Cousins Hill, Professor Borns presented a cross section showing how water is stored inside. The water table he said, mirrors the shape of the contours of the hill. At the edges of the hill, the ground water can emerge under pressure, an artesian well or spring. An audience member asked if removing gravel decreased the amount of water stored in the hill, he answered yes. In fact, he added, as pits are dug deeper, the water table will continue to drop, reflecting the contour of the land above it, resulting in decreased water storage. In addition, disturbing the top layer compromises the purifying ability of the gravel, since the “good bacteria” live in the soil above the gravel. Gravel alone does a poor job of filtering water he explained, and the state law which allows extraction to five feet above the water table is inadequate in Dr. Borns’ opinion. In the case of Lamoine’s Cousins’ Hill, if the water table were lowered to the level of marine mud, it could seriously impact the aquifer. Left alone, new soil will form in the pit and again purify the ground water, but only if there is enough separation between the soil surface and the water table. Continual disturbance of the pit floor as the gravel is extracted, along with the constant danger of spills will not protect our ground water.

How the proposed expansion of Harold MacQuinn’s Kittridge Pit will affect the Cold Spring Water Company’s water quantity and quality was clearly a concern in the question and answer session after the talk. Watch the whole video here.


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