I designed this WebQuest for my high school Environmental Science class. In one of our first units, we spend time on each of the Earth's "spheres".....atmosphere first, then geosphere, and finally, hydrosphere. As we study those three, we tie the biosphere in and identify interconnections along the way.
I like to think of this section of my unit as an upside-down triangle. I have students learn about the layers of the Earth (broad/triangle base; they use a YouTube video, ~5 min), narrow it down to the lithosphere, crust, and plate tectonics (narrower part of triangle; they use a Learner.org interactive website), and then we work down to the "tip of the triangle" by focusing on soil (from Discovery Education). I do it this way because we follow this WebQuest with a soil sample activity.
I have 45 minute periods and give my students an entire period to work on this. If they do not finish, it is homework. I also have an extra credit opportunity built in--watching Bozeman Plate Tectonics and attaching notes. Feel free to remove that if it does not work for your class.
While I use this in Enviro Sci, this would work equally as well in Earth Sci.
Note that I do not have a key with this version of my product.