ENV100Y5 Lecture Notes - Lecture 5: Interstellar Cloud, Gravitational Collapse, Ultraviolet

• School: UTM
• Department: Environment
• Course: ENV100Y5
• Professor: Barbara Murck

Document Summary

Note: terminology is not a detail it is the basic language of the discipline. The time scale of earth history: age of sun and solar system: ~ 4. 57 ga (ga = billions of years) Based on models of stellar evolution and dating of primitive solar system objects. Carbonaceous chondrites (meteorites: age of earth: ~ 4. 54 ga. Based on ages of terrestrial rocks + age of solar systems + models of solar system formation. Oldest rock is 4 ga old ancasta gneiss: note: prof. murck showed a rock fragment in class. Tiny white spheres throughout rock called chondrules. Piece of most primitive material in solar system. White chondrules are droplets of material in solar system at the time. Primitive because it has not been affected by current earth processes (erosion, etc. : other small rock formations that have been found contain mineral grains that are much older than the rock itself. The crust of the earth is being recycled (plate tectonics)