Brian de Ruiter
Atmosphere Effects: Mine/ Cave Walls
You might be able to create the walls using those large panels of styrofoam and then carving them with hot knife tools like they sell at Hot Wire Foam Factory. With the right tool you might be able to mimic the shape left behind by pic axe type tools. Also when I think of old mine shafts I think of the old rotting beams like in this picture. You could probably make fake beams out of the styro as well. Good luck and post some pics when you are done.
Up for a Treasure Hunt?
Top 10 Treasure-Hunting Hot Spots: Thunder Eggs/Geodes- Deming, New Mexico; Opals- Denio, Nevada and Lakeview, Oregon; Meteorites- Glorietta Mountain in New Mexico and Brenham Township, Kansas; Jade- Big Sur, California; Emeralds- Hiddenite, North Carolina; Dinosaur Fossils- Devil Hills, South Dakota; Diamonds- Murfreesboro, Arkansas; Gold- Pine Grove, California; Aquamarine- Spruce Pine, North Carolina; Turquoise- Tonopah, Nevada