Williston

Physical Landscape

The physical landscape of Williston may be thought of as the canvas on which the cultural and ecological landscapes are painted. It consists of the bedrock geology, surficial geology, soils, and hydrology, which all interact to provide the environmental conditions that determine broad-scale patterns of vegetation and wildlife, as well as human activities on the landscape.

The story of Williston’s physical landscape begins about 1.2 billion years ago with the formation of an ancient mountain range that has long since eroded away. This story continues with collisions between continental plates floating atop Earth’s molten mantle that formed Williston’s various bedrock types and essentially ‘squeezed up’ the Green Mountains. Then during the last ice age the two-mile-thick Laurentian ice sheet scoured the landscape and deposited a mix of surficial materials called glacial till as it advanced all the way to Long Island, New York. When this ice sheet retreated, colossal volumes of melt water filled the Champlain Valley all the way up to Williston’s Green Mountain foothills.

Sediments deposited by these waters comprise the materials that underlie Williston’s lowlands. Since the ice age concluded, present-day soils have been forming through processes of erosion. These processes are associated with interactions between the climate, water, vegetation, and human land use. Today the story continues, but at much less than a snail’s pace by human standards, as North and South America drift further from Eurasia and Africa.