°Pahoehoe Lava - One of the more interesting types of pahoehoe lava is called ropey pahoehoe & looks like a series of twisted ropes spaced evenly along the ground. The twisted ropes may be fairly straight, or may loop & wind in & out much like a fingerprint.
Great culminating project ideas for a literature study of "The City of Ember". Includes a rubric. I have used this successfully in my 5th grade class for several years. The students really enjoy choosing among these projects and presenting them to the class.