Across
- 3. The movement of magma onto the surface of the earth through volcano craters and cracks in the earth's crust, forming igneous rock
- 5. The true age of a rock or fossil that tells scientists the number of years ago a rock layer
- 6. A widely distributed fossil of a narrow range in time, used to determine the age of related rock formations
- 8. A scientist that studies fossils
- 9. A division of geologic time marked by distinctive developments and events
Down
- 1. The entry of molten rock or magma into or between other rock formations
- 2. The remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock
- 4. The divisions that show timing and relationships between events that have occurred during the history of the Earth
- 7. cylinders of ice drilled from glaciers and ice sheets