Page 21 Homework : 1. Color each rock layer and Complete Determining Which is Older worksheet Page 22 Friday, September 23, 2011 Monday, September 26, 2011 Complete Determining Which is Older Worksheet Friday, September 23, 2011 Monday, September 26, 2011 Warm Up: Copy and Match definition with term. Name the three types of rocks AND describe how each is formed a. ___________ - ______________________ b. ___________ - _______________________ c. ____________ - _____________________ In which layer would you expect to find the most fossils? Why? Law of Superposition Relative Ages of Rocks Activity Law of Superposition - The law states that strata that are younger will be deposited on top of strata that are older, given normal conditions of deposition. if undisturbed, oldest on the bottom and youngest on the top Strata – horizontal layers of rocks Unconformity - a buried erosion surface separating two rock masses or strata of different ages (this is where the pattern changes)erosion rockstrata Intrusions and Extrusions: Make of Igneous Rock and always younger than the rock layer it cut through Movement of Tectonic plates can disturb layers Can bend layers like a taco Molten lava can cut through layers

Warm Up: 1.When studying an undisturbed rock core, how do you know which is the oldest and youngest rock layer? 2.When might the youngest layer in sedimentary rock not be on the top? 3.Can you determine the exact age of rock by studying layer positions? 4.Use what you have learned last period to write a definition for relative age. Page 23 Homework : 1. Create Graph from Radioactive Activity 2. Answer the questions that go with the activity from class. 3. Read Section 2.3 of Unit A of textbook - Answer questions 1-3 Radioactive Dating, Half Life and Absolute Age Notes “Sweet” Radioactive Simulation Page 24 Tuesday, September 27, 2011 Wednesday, September 28, 2011 Complete Radioactive Dating Activity Graph and Questions Read Section 2.3 of Unit A in textbook (Answer ?’s 1-3) - Radioactive elements only occur in igneous rocks that are formed by magma. - As soon as the igneous rock is formed, it starts to decay and change into another element. Half Life – the time it take for half of the radioactive atoms to decay - constant for each element - Carbon’s Half Life = 5,730 years - used to date living organisms - Potassium- 40’s Half Life = 1.3 billion yrs Absolute Age - Geologists use radioactive dating to calculate the absolute ages of rocks - Moon rocks = 4.6 billion years old Radioactive Decay- When rocks contain unstable elements that break down releasing particles and energy Tuesday, September 27, 2011 Wednesday, September 28, 2011 Absolute Age vs. Relative Age **Please have your Determining Which is Older worksheet out so I can check it. If you have your progress report, please put it on the supply box.

Technology Used to Measure Radioactivity Geiger Counter Ionization Chamber MicroR Meter

Half-Lives Almost always need to make a chart to visualize Original Rock 1 Half Life2 Half Lives 3 Half Lives4 Half Lives

Half Lives Percentage of Radioactive Material in Rock Number of Half Lives 100% - 50%1 50% - 25%2 25% %3 12.5% %4 6.25% %5 Element Brennan is found in an igneous rock and we are trying to determine the rocks age. We know Brennan’s half life is approximately 3,000 years and that the rock is currently 25% radioactive. How old is the rock? 75% decayed 94% decayed 87.5% decayed 50% decayed 50% Radio- active 25% r-a 12.5% 6% 100% Radioactive Igneous Rock One Half Life Two Half Lives Three Half LivesFour Half Lives Element Brennan is found in an igneous rock and we are trying to determine the rocks age. We know Brennan’s half life is approximately 3,000 years and that the rock is currently 6.25% radioactive. How old is the rock? Element Brennan is found in an igneous rock and we are trying to determine the rocks age. We know Brennan’s half life is approximately 3,000 years and that the rock is currently 50% radioactive. How old is the rock?

Half-Lives Last Practice Question: A rock contains a radioactive element with a half life of 100 million years. Tests show that the element in the rock has gone through three half lives. How old is the rock?

Japan Radioactive ways can be harmful to our health

Ticket Out the Door Make a Venn Diagram to compare and contrast absolute and relative age. – Which does radioactive decay fall under? – Which does law of superposition fall under?

Warm Up: Put rock layers in order from oldest to youngest. Explain your reasoning. Page 25 Homework : 1. Work on Castle Learning Assignments 2. Prepare your notebook for a check! Index Fossil Notes Index Fossil Activity Page 26 Thursday, September 29, 2011 Friday, September 30, 2011 Work on Castle Learning Assignments Prepare your Notebook for a Upcoming Check!! -Scientists have determined when specific fossilized organisms lived -Knowing this helps determine rocks age Index Fossils – Organisms that lived in many areas during only a specific time span (extinct now) - Knowing the time span that organism lived, can help to estimate the rocks age - Can be used to compare the ages of rock layers in different parts of the world Example – Mollusk Inoceramus labiatus is a sea creature that lived many years ago - It appeared on Earth 144 million years ago - It became extinct 65 million years ago - If we find a rock layer that has this fossil in it, we know the rock is between the ages of 144 and 65 million years old Fossil Formation – An organism that was fossilized in rock must have lived during the same time span in which the rock formed. Thursday, September 29, 2011 Friday, September 30, 2011 A C B D E F 1 G I H 2 J L K L M M N N O P 3

Warm Up: 1. Make a Venn Diagram to compare and contrast absolute and relative age. Don't forget to include radioactive decay law of superposition carbon-14 index fossils half- lives 2. A rock contains a radioactive element with a half life of 100 million years. Tests show that the element in the rock has gone through three half lives. How old is the rock? Page 27 Homework : 1. Study for Quiz! Notebook Check (1-26) Centers Page 28 Monday, October 3, 2011 Tuesday, October 4, 2011 Study for Quiz on Determining Rock Age Monday, October 3, 2011 Tuesday, October 4, 2011

Warm Up: Complete the Standardized Test Practice activity on page 73A. Complete Page 29 Homework : 1. Section 2.3 Word Triangles: Uniformitarianism, Geologic Time Scale, Eon, Era, Period and Epoch 2. Research assigned Era for Geologic Time Project Rock Age/Layers/Fossils Quiz Epoch Article Launch Geologic Time Project Page 30 Wednesday, October 5, 2011 Thursday, October 6, 2011 Section 2.3 Word Triangles: Uniformitarianism, Geologic Time Scale, Eon, Era, Period and Epoch Research assigned Era for Geologic Time Project Wednesday, October 5, 2011 Thursday, October 6, 2011