Chapter 8 Section 1 Pages #s 1-4 Determining Relative Age 1. Explain why it is important for scientists to be able to determine the relative age of rocks. So they can understand the age and history of Earth 2. State the principle of uniformitarianism in your own words. Its like what happened in the past is just like what is happening now man. 3. Explain how the law of superposition can be used to determine the relative age of sedimentary rock. According to the law, a rock layer is always younger than the rock layer below it if the layers are undisturbed. 6. Describe how the law of crosscutting relationships helps scientists determine the relative age of rocks. The law of crosscutting relationships helps scientists understand that a body of rock or fault is always younger than any other body of rock that it cuts through. Chapter 8 Study Notes The Rock Record Section 1: Determining Relative Age 1 The principle of __________ states that current geologic processes can explain ______ processes. uniformitarianism uniformitarianism past past 2 The age of an object in relation to the ages of other objects is _______ age. relative relative 3 _______ age is the order in which two or more rock layers formed. Relative Relative 4 The law of _____ states that a sedimentary rock layer is ____ than the layers above it and _______ than the layers below it. superposition superposition older older younger younger 5 Younger layers of undisturbed _________ rock are above older layers according to the law of ___________. sedimentary sedimentary superposition superposition 6 ___________ ________ states that undisturbed sedimentary rock remains in _________ layers. Original horizontality Original horizontality horizontal horizontal 7 A fault or body of rock is younger than any other body of rock it cuts through according to the law of ________ ______. crosscutting relationships crosscutting relationships 8 With the law of _________ relationships an igneous intrusion is _______ to a layer of sedimentary rock in which it is found. crosscutting crosscutting compared compared 9 An _________ is an _________ in the geologic record. unconformity unconformity interruption interruption The End !!!