Flowing Artesian Well

While I was visiting my college friend, Steve, in Mount Pleasant, MI -- we went for a hike at Deerfield Park.  This is a 591 acre park located along the banks of the Chippewa River.  This recreational area includes cross country ski trails, two disc golf courses, ten remote campsites, a sledding hill, fishing, boating, and more.  The park also includes a covered bridge and an artesian well.  Here are a few pictures of our hike.....

My favorite part of the park is the artesian well.  It was very icy, but Steve carefully drank directly from the well.

So just what is an artesian well?  First of all, artesian wells are associated with confined aquifers containing groundwater that is under positive pressure. An aquifer is a geologic layer of porous and permeable material such as sand and gravel, limestone, or sandstone, in which water is stored.  An artesian aquifer is confined between impermeable rocks or clay.

When the water saturated layer is squeezed between layers of impermeable rock or clay, the geometry of the layers can create positive pressure, which can cause the water to rise to a point where it can be forced to the surface either naturally, or by being tapped with a pipe.  A well drilled into such an aquifer is called an artesian well if water reaches the ground surface under the natural pressure of the aquifer, in which case the well is called a flowing artesian well.

The source for the Artesian Well in Mount Pleasant may be the Mississippian aquifer, located under the central lower peninsula of Michigan.

CITES
Andrew Dunn: http://commons.wikimedia.org/wiki/File:Artesian_Well.png
http://en.wikipedia.org/wiki/Artesian_aquifer
http://pubs.usgs.gov/gip/gw/artesian.html
http://pubs.usgs.gov/ha/ha730/ch_j/jpeg/J065.jpeg