Across
- 4. a flowing mass of ice and snow that forms on mountaintops and near the north and south poles
- 5. dating-the comparison of fossils in different rock layers to determine how old a rock or fossil is
- 7. the conditions of the atmosphere (temperature, humidity, wind speed, and precipitation)
- 8. fossil-certain fossils known to exist in a particular time and place that may be used to determine the age of rocks or other fossil
- 10. age- a global climate marked by long periods of cold temperature that cause glacial formation and expansion
- 12. when a species no longer has living members in existence
Down
- 1. record- all of the fossil that have ever been found, which scientists use to understand earth's history
- 2. cycle- the circulation of water through the hydrosphere from earth's surface to the atmosphere and back
- 3. the average weather in a location over 30 year or more
- 6. the transport of sediment by wind, water, or gravity
- 7. breakdown of rock into smaller pieces from exposure to wind, water, gravity, change in temperature, and/or biological forces
- 8. core- cylinder of ice drilled out of glaciers that contain layers of snow, dust, volcanic ash, atmosphere gases, and microbes from past time periods
- 9. till-the eroded sediment that is deposited as glacial retreat and expand
- 11. the remains of ancient animals and plants, the traces or impressions of living thing from past geologic ages, or the traces of their activities