CHAPTER NEW CHAPTER Views of Earth’s Past the BIG idea Rocks, fossils, and other types of natural evidence tell Earth’s story. 9.1 Earth’s past is revealed in rocks and fossils. 9.2 Rocks provide a timeline for Earth. 9.3 The geologic time scale shows Earth’s past. CHAPTER OUTLINE CHAPTER RESOURCES
9.1 Earth’s past is revealed in rocks and fossils. Fossils are traces or remnants of past life. Many fossils are found in rock. Rocks, fossils, and other natural evidence provide information about how Earth and life on Earth have changed over time. fossil original remains ice core A cast fossil is formed when minerals take the shape of a decayed organism. VISUALIZATION CLASSZONE.COM Explore how fossils form. CHAPTER RESOURCES SECTION OUTLINE
9.1 Trace Fossils Earth’s past is revealed in rocks and fossils. original remains ice core CHAPTER RESOURCES SECTION OUTLINE
Rocks provide a timeline for Earth. 9.2 Rocks provide a timeline for Earth. Sedimentary rock layers show the order in which rocks formed. The order of the layers is used to determine the relative ages of fossils found in the rock. relative age index fossil absolute age half-life Radioactive dating can be used to determine the absolute age of igneous rock. CHAPTER RESOURCES Scientists combine information about the relative and absolute ages of rocks and fossils to construct a timeline of Earth. SECTION OUTLINE
Rocks provide a timeline for Earth. 9.2 Rocks provide a timeline for Earth. Scientists combine information about the relative and absolute ages of rocks and fossils to construct a timeline of Earth. relative age index fossil absolute age half-life VISUALIZATION CLASSZONE.COM Watch molten rock cut through layers of sedimentary rock. CHAPTER RESOURCES SECTION OUTLINE
The geologic time scale shows Earth’s past. 9.3 The geologic time scale shows Earth’s past. The geologic time scale divides Earth’s history into eons, eras, periods, and epochs. The divisions are based on major changes or events that occurred in Earth’s history. uniformitarianism geologic time scale EON EPOCH ERA PERIOD today *bya = billion years ago †mya = million years ago Phanerozoic eon Cenozoic era Mesozoic era Paleozoic era Proterozoic eon Archean eon Hadean eon Precambrian time 500 mya† 4.6 bya* 3 bya 2 bya 1 bya CHAPTER RESOURCES SECTION OUTLINE
Earth’s past is revealed in rocks and fossils. 9.1 Earth’s past is revealed in rocks and fossils. I. Earth’s past is revealed in rocks and fossils. fossil A. Rocks, fossils, and original remains give clues about the past. original remains ice core 1. Original Remains 2. Fossil Formation 3. Fossils in Rocks B. Fossils and other natural evidence show changes in life and the environment. 1. Tree Rings CHAPTER RESOURCES 2. Ice Cores KEY CONCEPT SUMMARY
Rocks provide a timeline for Earth. 9.2 Rocks provide a timeline for Earth. II. Rocks provide a timeline for Earth. relative age A. Layers of sedimentary rocks show relative age. index fossil absolute age 1. Igneous Rock and Sedimentary Layers half-life 2. Index Fossils B. Radioactive dating can show absolute age. 1. Half-Life 2. Using Absolute and Relative Age CHAPTER RESOURCES KEY CONCEPT SUMMARY
The geologic time scale shows Earth’s past. 9.3 The geologic time scale shows Earth’s past. III. The geologic time scale shows Earth’s past. uniformitarianism A. Earth is constantly changing. geologic time scale B. The geologic time scale divides Earth’s history. 1. Divisions of Geologic Time 2. Phanerozoic Eon CHAPTER RESOURCES KEY CONCEPT SUMMARY
Chapter Resources Image Gallery CHAPTER HOME Chapter Resources Image Gallery Click here to view chapter images and animations Click on the items below to access resources on CLASSZONE.COM Audio Readings Hear chapter audio readings Resource Centers Get more information on select science topics Content Review Review key concepts and vocabulary Standardized Test Practice Practice state standardized tests Math Tutorial Review math concepts BACK TO CHAPTER