Vegetation, water table, surficial geology

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Some trees, like eastern white pine, prefer well-drained soils, and sandy deposits or hilltops and ridges are great locations for draining water away from the surface.  Other trees, like this larch/tamarack/hackmatack/larix laricina pictured above, are often in wetter soils, at the edge of bogs or mud holes where the swamp donkeys socialize.  If we mentally remove the vegetation, and look at the patterns of sand, mud, or rock deposits underneath, we can begin to interpret the legacy of the Laurentide Ice Sheet that covered Maine during the last ice age.  The ice sheet had rivers running through it, to drain the meltwater, think of it as the glacier’s plumbing network.  These rivers contained sand and rounded cobbles and when the ice sheet melted away, the sand and rounded cobbles rested onto the landscape.  Other parts of Maine were below sea level, and mud, clay, silt and other fine particles settled out of the ocean and onto the land surface.  As investigators of earth, we can look at the vegetation, think about the drainage of the soil and how that relates to glacial deposits in New England.

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