Across
- 3. A flammable mixture of gases, including methane (CH4)
- 4. Oil leaking out of a drilled well
- 7. Energy resources that do not replenish within the timeframe of human society.
- 11. technique used to extract natural gas from rock formations that are normally impermeable
- 15. Forms of nonrenewable energy that arise from the remains of living organisms over millions of years.
- 16. Layers of coal within rock that are thick enough to be profitably mined
- 17. Carbon-rich liquid found within rock strata millions of years old
- 18. When plants pull carbon from the atmosphere
- 19. Needs to be turned by the steam from boiling water
Down
- 1. Most coal formed during this geologic time period
- 2. Uses explosives to blow up entire mountaintops to allow surface mining of coal seams underneath
- 5. Mining that removes coal through deep tunnels or shafts
- 6. Disease coal miners can get from breathing in dust
- 8. Energy returned on investment
- 9. The most common rock that contains methane.
- 10. Burns the coal to produce mechanical energy
- 12. Ratio that estimates how much of a resource we have left at current rates of use
- 13. Fiber in carboniferous plants that bacteria and fungi could not digest
- 14. A hard, blackish substance that is formed from plant matter that has been highly compressed and pressurized