Topic: Absolute Dating Absolute Dating is the real, true age of the rock

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Topic: Absolute Dating Absolute Dating is the real, true age of the rock Slide 2 Examples - Tree Rings Slide 3 Varves Layers of sedimentary rock that were formed in a lake from season to season Slide 4 Slide 5 Radioactive Dating - Slide 6 Absolute Dating Radioactive elements decay steadily. 1.- 2.- 3.- 4.- 5.- Slide 7 Slide 8 Slide 9 Examples Front of ESRT Slide 10 Parent Isotope Daughter Isotope Slide 11 Slide 12 # of Half-LivesHalf-Life of Carbon-14 Age of Rock (years old) % of Carbon Remaining % of Nitrogen 0 1 2 3 4 5 6 Slide 13 Example of Half Life Your rock contains 3 grams of C 14 and 9 grams of N 14. How old is your rock? - Slide 14 Example of Half Life A sample of wood that originally contained 100 grams of carbon 14 now only contains 25 grams of carbon 14. Approximately how many years ago was this sample part of a living tree? - Slide 15 Example of Half Life A rock contains 5 grams of Uranium 238 and 35 grams of Lead 206. How old is the rock? - Slide 16 Example of Half Life A fossil contains 5 grams of carbon 14 and 75 grams of Nitrogen 14. How old is the fossil? - Slide 17 Final Question: A rock containing Potassium 40 undergoes 3 half lives, what is the age of the rock? - Slide 18 Topic: The Earlier Earth Slide 19 Law of Uniformitarianism The present is the key to the past. - Slide 20 Earth is a Dynamic and Evolving Planet Changes in its surface Changes in life Slide 21 Origin of Our Solar System Solar nebula theory Slide 22 The Planets Slide 23 Planetesimals have formed in the inner solar system, and large eddies of gas and dust remain far from the protosun. - Sun and Rotating Cloud Slide 24 How old is the Earth? 4,600,000,000 = - Slide 25 An Early Earth - Heat sources: - Slide 26 Earths Differentiation Early Earth - - Lighter silicates flowed up to form mantle and crust. Why? Slide 27 The Moon - Slide 28 Slide 29 Earlier Earth Atmosphere - Slide 30 Ocean Formation - Slide 31 Exploring Geologic Time What has been around for a long time to help geologist study the Earth? Slide 32 Slide 33 Final Question: The geologic history of an area can best be inferred by studying A) erosional processes affecting the area B) plants and animals now living in the area C) present climatic conditions of the area D) bedrock compositions and rock structures in the area