Presentation on theme: "Do Now 1.Get How Fossils Are Madearticle, Relative Dating lab and notes from brown cart in front of room. 2.Read How Fossils Are Made. 3.Complete crossword."— Presentation transcript:
Do Now 1.Get How Fossils Are Madearticle, Relative Dating lab and notes from brown cart in front of room. 2.Read How Fossils Are Made. 3.Complete crossword puzzle on back. 4.Homework: Complete crossword puzzle; finish Set A questions for Relative dating.
What are fossils? Brainstorm with your shoulder partner Definition: remains of organisms preserved in the earth
What are fossils? Bones Parts of organisms replaced by minerals
How do scientists know that woolly mammoths lived more than 40,000 years ago?
Finding the age of fossils Two methods: Relative dating: – One fossil is compared to another to determine which came first – Where fossils are discovered provides major clues about sequence of events on earth
Finding the age of fossils Absolute dating: – Scientists measure the amounts of radioactive elements found in fossils – By measuring the amount of lead or carbon in a fossil, its age can be determined.
Law of Superposition In an undisturbed sequence of rocks, the oldest rock layers will be on the bottom,with younger rocks on top. Why to we care about the age of rocks? Because it helps us determine how old fossils are. Can date the fossils by which rock layer they are found in.