Plate Tectonics

2. The rule stating that in layers of rock, the oldest are at the bottom and the youngest are at the top.
4. This principle suggests that Earth's features were formed by the same forces—like wind and water—that we observe today.
10. The ancient supercontinent that contained all of Earth’s landmasses before they drifted apart
11. A plate boundary where crust is neither created nor destroyed, but instead scrapes along its neighbor.
13. This phenomenon occurs at divergent boundaries under the ocean, making the Atlantic Ocean wider every year (2 words)
15. The scientific theory explaining how Earth’s "puzzle pieces" shift and slide.(2 words)
16. The specific area where a denser oceanic plate sinks beneath a lighter continental plate. (2 words)
17. Alfred Wegener’s famous idea that the world’s landmasses have slowly shifted across the ocean floor over millions of years (2 words)
19. When hot, molten rock squeezes into existing rock layers and cools.
21. The raw materials—like mud, sand, and pebbles—that get squeezed together to form new rock layers

1. When these massive pieces of Earth's crust collide, pull apart, or grind past each other, they create mountains and volcanoes (2 words)
3. The solid, outer layer of Earth consisting of the crust and the very top of the mantle
5. A fossil used as a "time stamp" to help scientists identify the specific age of a rock layer. (2 words)
6. Often compared to the "pages" of Earth's history book, these are the individual layers of sedimentary rock.
7. The type of boundary where tectonic plates divide or move in opposite directions.
8. A method used to determine if a rock layer is older or younger than the ones around it without giving a specific age (2 words)
9. Unlike relative dating, this method provides a specific number for how many years ago a rock formed
12. Unlike weathering, which breaks rocks, this process transports the pieces to a new location.
14. Whether it's pulling apart or sliding, this is the physical break where tectonic plates meet and shift.
18. This boundary is a "mountain builder," created when two plates push against each other
20. This is the only rock type where you are likely to find fossils tucked between its layers.