CHESTERVILLE — There once was beachfront property in New Sharon and Chesterville — deep in Franklin County — according to researchers studying strange mounds about town.

Dr. Patricia Millette and her Mt. Blue High School students began studying strange mounds found on Cape Cod Hill in New Sharon. Two years ago, one of her students thought that mounds found near his Chesterville home might have a similar origin and Chesterville Hill and Zions Hill were added to the investigation.

According to Millette, the story begins in New Sharon. The bridge in that town is a lot higher than the one in Farmington Falls. As glaciers retreated, she said, they sought out low-lying areas. The glaciers came in two directions and dumped a lot of ice in the Sandy River. Some scientists believe that a glacial lake formed along the Sandy River when all of the low-lying areas were backed up with water.

Marine sediments have been found in New Sharon and as far away as Strong, indicating seawater was there at one point. Delta remnants have also been found along Wilson Stream and McGurdy Brook, and significant deposits of silts and clay have been found in Farmington Falls.

Millette and her students developed several theories for the mounds and how they were formed. One idea was that they were a continuation of the Chesterville esker, but she wasn’t sure whether there was too much disruption by the upland to continue on to the larger hills in the area.

Another theory centered on kames, big sediment piles that collect on the surface of the glacier and fall into piles on the ground as the glacier melts.

The third idea was that of dunes. Deposits of this type depend on an adequate sediment supply and an appropriate wind regime. Author D.W. Caldwell, who wrote “Roadside Geology of Maine” in 1998, had suggested this theory several years ago, but no supporting evidence was available.

Millette’s final idea was that the mounds were ancient burial grounds.

“With the help of very clever high school students, we investigated,” Millette said.

They took soil samples and completed standard grain-size analysis to separate the particles according to size.

Preliminary work was done on Cape Cod Hill, but some landowners denied access and it was easier to get at locations in Chesterville, so the focus shifted to that area.

Junior Roshan Luick did an independent project to study the cemetery on Pope Road. She found several small mounds. Similar findings were on Cape Cod Hill, where there were mounds within mounds.

Almost all of the mounds are made up of about 80 percent sand and 20 percent mud, according to Millette. One eagle-eyed student found tiny shell fragments.

Sophomore Ben Andrews studied the Zions Hill area, but one mound didn’t follow the same pattern as others.

Millette said the findings were getting complicated. From the work completed to date, the data suggest most of the mounds are coastal sand dunes.

“The folks on Chesterville and Zions Hill and Cape Cod Hill once had beachfront property,” she said.

The findings of Millette and her students suggest that the dune on Cape Cod Hill formed well before any of the others. At one time, all three hills were surrounded by water, they theorized.

Luick said, “When the water receded, marine sediments draped over other objects or piles of glacial till.” 

Millette said the findings are inconclusive. She would like to look for more dunes and see if they moved over time. She would also like to monitor groundwater flow, since all dunes have good aquifer potential, and re-examine the mounds already mapped using ground-penetrating radar.

Luick said she wants to continue in science. Her involvement with Millette’s research made Luick see science in a different way.

“I never would have seen it in a chemistry class,” she said.

Luick wrote a long paper on the students’ work and presented her findings at the Spring Conference of the Geology Society of Maine.

Millette said Luick’s work was similar to that done by undergraduate- or graduate-level students. The society created a new category this year to reward Luick for her efforts.

Andrews plans to present next year with other students in his class. They studied one mound and he is considering doing an independent study.

“I am very interested in STEM (science, technology, engineering and math),” he said.

Millette said that a lot of the work she has undertaken came about from word of mouth. If anyone is interested in having their property studied, they should contact her through her school email at pmillette@mtbluersd.org.

pharnden@sunmediagroup.net