Clues to Earth's Past

1. Fossils:
are the remains, imprints, oe traces of prehistoric organism.

2.Permineralized remains:
are fossils in which thespaces inside are filled with minerals from groundwater.

3. Carbon Film:
is a thin film of carbon,residue is left, forming a silhouette of the original organism.

4. Mold:
 is the hard part might decay or dissolve, leaving behind a cavity in the rock.

5. Cast:
is the mineral-rich water or other sediment might enter the cavity.

6. Index Fossils:
are the remains of species that existed on Earth for relatively short periods of time, were abundant, and were widespread geographically.

7. Principle of Superposition:
undisturbed layers of rocks.

8. Relative Age:
is its age in comparison to other things.

9. unconformities:
are gaps in rock sequences.

10. Absolute Age:
is the age, in years, of a rock or other object.

11. Radioactive Decay:
is the process of breaking down.

12. Half-Life:
is the time it takes for half of thecarbon -14 is 5,730 years.

13. Radiometric Dating:
 is the process of the absolute age of rock.

14.Uniformitarianism:
Is a principle is often paraphrased.

Water Erosion and Deposition

 1. Runoff:
Water that doesn't soak into the ground or evaporate but instead flows across Earth's surface.

2. Channel: 
Water moving down the same path creates a groove .

3. Sheet Erosion:
Occurs when water that is flowing as sheets picks up and carries away sediments.

4. Drainage Basin:
Is the area of land from which a stream or river collects runoff.

5. Meander:
Is the curve grows to become a broad arc.

6. Groundwater:
Water that soaks into the ground collects in these pores and empty spaces.

7. Permeable:
Water that can pass through them.

8.  Impermeable:
Water that cannot pass through them.

9. Aquifer:
A Layer of permebale rock that lets water move freely.

10. Water Table: 
Is the upper surface of this zone.

11. Spring:
Are found on hillsides or other places where the water table meets a sloping surface.

12. Geyser:
Is a hot spring that erupts periodically, shooting water and steam into the air.

13. Cave:
Are the cracks in the limestone enlarge until an underground opening.

14. Longshore current:
Water that runs parallel to the shoreline.

15. Beaches:
 Are deposits of sediment that are parallel to the shore.