Explore the surface of the earth in a constant struggle with the elements of nature. Wind, gravity, temperature, and chemical reactions break down rock formations to form soils, river deposits, and dunes. 20 minutes. Grades 7-12. Shipped directly from the manufacturer. Not available with rush shipping. Delivery time estimated at 10-14 days or less. Gift wrap not available. Information on how to place your order by fax or by telephone. Product Number AM8620