Although the elements were originally created in the stars, 92 elements are found naturally here on earth. How they travel through earth's systems is very important; where they come from and where they go affects all life.

	Rock cycle	http://www.beyondbooks.com/ear82/7.asp http://www.scienceweb.org/burgess/geology/cycle1.html http://www.earthscienceeducation.com/inset.htm
	General information	http://geology.usgs.gov/index.shtml http://www.esse.ou.edu/fund_concepts/Fundamental_Concepts3/Geochemical_Cycles/Carbon_Cycle/Carbon_Cycle.html  http://www.ucmp.berkeley.edu/exhibit/geology.html http://www.geology.enr.state.nc.us/proj_earth/proj_earth.html http://www.bbc.co.uk/education/rocks/index.shtml
	Types of rocks	http://www.dc.peachnet.edu/~pgore/geology/historical_lab/rocks_minerals.php http://www.science.ubc.ca/~geol202/petrology/rock.html
	Minerals	http://mineral.galleries.com/minerals/by_class.htm
	Virtual Cave visit	http://www.goodearthgraphics.com/virtcave/index.html
	Sand Identification exercise	http://www.paccd.cc.ca.us/instadmn/physcidv/geol_dp/dndougla/SAND/SandExrc.htm
created 7/9/02	last update 4/17/03	bonus question: How does weathering of rocks contribute to "hard water"?