Across
- 2. the name of the supercontinent that existed from about 300-200 million years ago
- 4. rock cycle, the process where molten rock ( magma) cools and solidifies to form igneous rocks
- 6. 541-252 million years ago means ancient life
- 9. fossil, the remains of plants and animals that have existed only for a limited geologic period
- 11. a crack in the earths crust where two blocks of rock move relative to each other
- 12. dating, a method for determining the age of a geologic structure in relation to other structures
- 14. of superposition, one of the principles of geology scientists use to determine the relative ages of rock strata, or layers
- 15. a geologic period that lasted from 252-66 million years ago
- 16. the name given to the idea that natural processes behave more or less in the same way today as they have throughout the past and will continue to do so in the future
- 17. drift, the theory that earths continents move relative to each other over time
Down
- 1. the current geological era of Earth, beginning 66 million years ago and continuing to present day
- 3. time scale, divides up the history of the earth based on life-forms that have existed during specific times since the creation of the planet
- 5. the earliest period of earths history from the formation of the planet to the beginning of the cambrian period
- 7. cores, cylindrical samples of ice taken from glaciers and ice sheets that preserve layers of ice formed over thousands of years
- 8. plates, large, irregularly shaped slabs of solid rock that make up the earths crust
- 10. rock cycle, the process where existing rocks are transformed into new rocks with different mineral compositions and textures due to intense heat and pressure deep within the earths crust
- 13. rock cycle, the process where existing rocks are weathered and eroded into smaller particles (sediments) which are then transported deposited compacted and cemented together to form new sedimentary rocks