Across
- 1. 87Sr
- 5. Number of high tides per day
- 6. Why kelvin's age was wrong
- 8. Where to measure geothermal gradient
- 10. When Theia hits proto Earth
- 12. After four half-lives
- 14. Meteorite with same composition as bulk Earth
- 15. Too abundant to be fossils
Down
- 2. Same forces, always at work
- 3. First geological map
- 4. Core
- 7. Earth's shape
- 9. Slope proportional to age
- 11. Obliquity
- 13. Tropical atmospheric circulation