Book:

1.       Charles C. Plummer, Diane H. Carlson, David McGeary, Carolyn Eyles, Nick Eyles, Physical Geology & the Environment, Second Canadian Edition (McGraw-Hill Ryerson Limited, 2007), 154, 186, 289.

Electronic Sources:

1.       Andreas Viklund,  Volcanic History and Recent Seismic Activity in the Yellowstone Region, http://skyblu.files.wordpress.com/2006/10/743px-yellowstone_caldera_map2.jpg.

2.       Andrew Alden, Basalt Columns, http://geology.about.com/library/bl/images/blbasaltcolumns.htm.  

3.       Author Unknown, Important Igneous Rocks: Basalt and Granite, http://www.atoms.albany.edu/deas/atmclasses/atm301/hydrorocks.pdf.

4.       Gary Larson, Sheep Cartoons, http://sheep.youssouf.com/old/gwynt/larsonCartoon.gif.

5.       Linda M.V. Martel, Pretty Green Mineral, Pretty Dry Mars?, http://www.psrd.hawaii.edu/WebImg/HIolivine.gif.

6.       The University of Texas at Austin, Map of Yellowstone National Park, http://www.lib.utexas.edu/maps/national_parks/yellowstone_map.jpg.

7.       Tom Pfeiffer, Thematic Volcano Photo Gallery: Basalt (Basaltic Lava), http://www.decadevolcano.net/photos/keywords/basalt.htm.  

8.       U.S. Department of the Interior, U.S. Geological Survey, Sheepeaters Cliff, Yellowstone National Park, http://volcanoes.usgs.gov/yvo/images/20010520-127-srb_caption.html.

9.       U.S. Department of the Interior, U.S. Geological Survey, Menlo Park, California, USA, Photo Glossary of Volcano Terms, http://volcanoes.usgs.gov/Products/Pglossary/basalt.html.