1. DO NOW! 1. List and define the four types of fossils 2. What is the most common fossil type? 3. What 2 conditions are best for fossils to form? 4. Where is the most common place to find fossils? 5. How can fossils be used to determine the age of rocks?

2. AGENDA DO NOW DO NOW REVIEW FOSSILS & GEOLOGIC TIME REVIEW FOSSILS & GEOLOGIC TIME GUIDED NOTES GUIDED NOTES FOSSILS & AGE OF ROCKS GRAPHING ACTIVITY (PAIRED EXERCISE) FOSSILS & AGE OF ROCKS GRAPHING ACTIVITY (PAIRED EXERCISE) GEOLOGIC TIME SCALE QUESTIONS GEOLOGIC TIME SCALE QUESTIONS EXIT TICKET EXIT TICKET

3. Geologic Time Rocks record geologic events and the changing life forms of the past. Rocks record geologic events and the changing life forms of the past. Uniformitarianism: The forces and processes that we observe today are basically the same as they were in the past. Uniformitarianism: The forces and processes that we observe today are basically the same as they were in the past.

4. Relative Dating Tells us the sequence (order) in which events occurred, but NOT HOW LONG AGO they occurred. Tells us the sequence (order) in which events occurred, but NOT HOW LONG AGO they occurred.

5. Stratigraphy= Study of rock layers 3 Laws/Principles: 1. Law of Superposition: 1. Law of Superposition: In an undisturbed sequence of sedimentary rocks, each bed is older than the one above it and younger than the one below it. In an undisturbed sequence of sedimentary rocks, each bed is older than the one above it and younger than the one below it.

6. Stratigraphy

7. Stratigraphy 2. Principle of Original Horizontality: Layers of sediment are generally Layers of sediment are generally deposited in a horizontal position. deposited in a horizontal position.

8. Folds Rocks can be folded in 2 directions. Rocks can be folded in 2 directions. -Anticline (A shape fold)= youngest rocks in outside -Anticline (A shape fold)= youngest rocks in outside -Syncline (U shape fold)=youngest rocks -Syncline (U shape fold)=youngest rocks in core of fold in core of fold

9. What type of fold is this?

11. Stratigraphy 3. Principle of Cross-Cutting Relationships: States that when a fault cuts through or States that when a fault cuts through or when magma intrudes into other rocks when magma intrudes into other rocks and crystallizes, we can assume that the and crystallizes, we can assume that the fault or intrusion is younger than the fault or intrusion is younger than the rocks affected. rocks affected.

12. Stratigraphy Inclusion: Pieces of rock units that are contained (included) within another. They are always older! Inclusion: Pieces of rock units that are contained (included) within another. They are always older!

13. Correlation and Unconformity Correlation: Matching up rocks of similar age in one area to rocks in another area close by. Use inclusions to make it easier. Correlation: Matching up rocks of similar age in one area to rocks in another area close by. Use inclusions to make it easier. Unconformity: A break in the rock record caused by erosion or a lack of deposition Unconformity: A break in the rock record caused by erosion or a lack of deposition Unconformities are represented by a squiggly line Unconformities are represented by a squiggly line

14. What is the youngest feature? K K K Unconformity

15. What events caused the unconformities at X, M and Y?

16. Review Sedimentary Rocks= Principle of Superposition, Principle of Original Horizontality and Inclusions Sedimentary Rocks= Principle of Superposition, Principle of Original Horizontality and Inclusions Igneous Rocks=Principle of Cross-Cutting Igneous Rocks=Principle of Cross-Cutting Metamorphic Rocks=Metamorphic Contact Zones (ALWAYS OLDER THAN OTHER ROCKS!) Metamorphic Rocks=Metamorphic Contact Zones (ALWAYS OLDER THAN OTHER ROCKS!)

17. Geologic Time Scale Geologic Time Scale is divided into distinctive time units based on interpretations of rock and fossil life forms. Geologic Time Scale is divided into distinctive time units based on interpretations of rock and fossil life forms. Covers all of Earth’s history (4.6 billion years) Covers all of Earth’s history (4.6 billion years)

18. Geologic Time Scale Eons > Eras > Periods > Epochs. Eons > Eras > Periods > Epochs. Eons represent the greatest expanse of time and Epochs the least Eons represent the greatest expanse of time and Epochs the least 88% of Earth’s history is within the Precambrian time period (almost 4 billion years 88% of Earth’s history is within the Precambrian time period (almost 4 billion years

19. Geologic Time Scale Eras are divided into 3 groups: Paleozoic (ancient life), Mesozoic (middle life) and Cenozoic (recent life) Eras are divided into 3 groups: Paleozoic (ancient life), Mesozoic (middle life) and Cenozoic (recent life) Index fossils record great worldwide changes in life and also are used to mark each boundary on the Geo Time Scale Index fossils record great worldwide changes in life and also are used to mark each boundary on the Geo Time Scale

20. Fossil Occurrence & Age of Rocks Graphing Activity Pg. 356-357 in textbook Pg. 356-357 in textbook Quietly at your desk with a partner Quietly at your desk with a partner Each student must complete their own graph Each student must complete their own graph

21. Geologic Time Scale Use chart on left side of paper to answer the questions located on the right side Use chart on left side of paper to answer the questions located on the right side Use complete sentences Use complete sentences Any unanswered questions must be completed for homework Any unanswered questions must be completed for homework DUE TUESDAY AT THE START OF CLASS! DUE TUESDAY AT THE START OF CLASS!

22. EXIT TICKET 1. What law explains that the youngest rocks are found on the top layer and the older on the bottom layer? 2. What law states that layers of rocks are deposited in a horizontal position? 3. What law states that a fault or intrusion is younger that the rock affected? 4. The Geologic Time Scale is divided into units based on what information?