Geologic Time

4. A missing piece of the rock record caused by a period of erosion, followed by the deposition of sediments.
5. type of dating that determines the order of past events, rocks, and fossils
6. Relationship between one rock or event and the rock it cuts through
10. Time needed for ½ of the radioactive atoms in a rock to decay
11. a fracture between two blocks of rock that allows the blocks to move.
12. This law states that in any undisturbed rock sequence, the youngest layer is on top and the oldest on bottom
13. Type of rock most likely to contain fossils

1. this law states that layers of sediment were originally deposited horizontally under the action of gravity. They might later be uplifted and turned
2. type of dating Used to determine the actual age of an object in years by measuring the amount of radioactive material as well as its decay product.
3. Rock formation that occurs when magma cools and solidifies inside a preexisting rock.
7. Type of rock most likely to contain minerals such as uranium
8. This type of decay involves the nucleus of an atom breaking down, changing the number of protons and the atom’s identity.
9. A fossil useful for finding the age of other fossils and rocks. Must be easily recognizable, abundant, have a wide geographic distribution and a short range through time.