Earthworks

Andy Goldsworthy, Red Leaf Patch, 1983
Red Earth,
http://www.redearth.co.uk/home2a.html

Earthworks refers to art made in nature by using materials such as stones, leaves, stick, ice and dirt. It is a contemporary art, that got its beginnings in the United States in the 1960s. The premise behind it is to emphasis man's relationship with nature by making art out of natural materials in a natural setting.

Earthworks would be very easy to explore in a classroom. Take the kids outside and see what they can find and build with the natural resources in their school yard and surrounding. Document it in picture or movie form.

Includes crop art, see Stan Herd's work:
http://www.millermeiers.com/stanherd/examples.html

Robert Smithson:
http://www.robertsmithson.com/index_.htm

A good overview, with lots of artist links:
http://www.artlex.com/ArtLex/e/earthart.html