Title: Our planet earth
Description: "Introduces students to the  concept of geological time (also called deep time); relative age dating of rock via the principles of stratigraphic superposition, original horizontality, and cross-cutting; absolute age dating by radioactive decay; the chemical elements, heavy and light, that make up the planet; and Earth's three main layers: crust, mantle, and core."--Container.
Subjects: Earth sciences, Geochronometry, Geological time, Video recordings for the hearing impaired