1. RELATIVE AGE OF ROCKS Lesson 10-2

2. Absolute or Relative? Anthony is the youngest. Melony is 4 years old. Michael is older then Sasha. Sasha is 16 years old. Ashley is older than Melony, but younger than Sasha.

3. Relative Dating Used to determine the order of events and the relative age of rocks by looking at the position of rocks in a sequence Numbers are not used Ex: “I am older than you.”

6. Law of Superpostion In an undisturbed layer of rock, the oldest rocks are on the bottom and the younger rocks are toward the top

8. Original Horizontality Layers of rock are initially deposited in flat, horizontal layers

9. Folding

12. Inclusion Older rock included in the formation of newer rock

15. Cross-cutting Intrusions igneous dikes ↑ and sills → Faults When one geologic feature ( younger ) cuts across another geologic feature ( older )

22. Unconformity When erosion removes existing rock layers and causes a gap in the geological record

28. Index Fossils

31. ID ages of different rocks