Earth Science Crossword

3. The amount of mass in a given volume (how compact something is)
6. Swirling heat currents that move the tectonic plates
8. A fragment of an older layer included in a younger layer
10. Rock that has undergone change from intense heat and/or pressure
12. The large, ancient landmass that existed when all the continents were together
14. The processes we see on Earth today worked the same way in the past
15. Largest layer of earth containing hot, molten rock
17. A layer that cuts through other layers is younger than the layers that it cuts
18. When two plates collide
19. The first scientist to theorize that Earth's continents were moving

1. The theory that earth's crust is broken up into large, moving plates
2. Rock that forms when magma or lava cools and solidifies
4. Oldest rock layers on bottom and youngest on top
5. Layer made of liquid iron and nickel
7. When two plates move apart
9. Rock that forms when fragments of other rocks (sediments) are compacted and cemented together
11. The outermost layer of Earth
13. When two plates slide past each other
16. Layer made of solid iron and nickel