Completar frases 1-Changes in Geology Over TimeVersión en línea Chapter 5, Lesson 5: "Earth´s Moving Continents". Use your textbook to help you fill in the blanks pages 296 - 305. Click the word. por Naneth Burquez 1 overturned half age sediment superposition life relative absolute age radioactivity amber imprints What is relative age ? 1 . - Two ideas that help scientists determine the age of rock layers are original horizontality and . 2 . - Scientist compare the age of one rock layer to the age of another to find its . 3 . - Layers of rock can be tilted , folded , or by forces within Earth , making it difficult to determine their relative age . What are fossils ? 4 . - Fossils can form when organisms die and are buried by , which replaces the hard parts of the body and hardens to form rock . 5 . - Some fossils are formed when organisms are trapped in flowing tree sap , which hardens to form . 6 . - Other fossils are formed when footprints or other quickly dry and become covered with sediment and preserved . What is absolute age ? 7 . - The discovery of allowed scientists to determine how old a rock layer or fossil really is . 8 . - Rocks contain radioactive elements that decay into other elements at a constant rate called - . 9 . - A rock layer´s age in years is its .
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