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What do the positions of rock layers tell us about Earth’s history?

What do the positions of rock layers tell us about Earth’s history?. What do you know about Earth’s History?. In your own words, explain what you know about Earth’s history. 1. Look at the next 5 photos and answer the questions about these photos on the slide that follows:. Grand Canyon.

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What do the positions of rock layers tell us about Earth’s history?

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  1. What do the positions of rock layers tell us about Earth’s history?

  2. What do you know about Earth’s History? In your own words, explain what you know about Earth’s history.

  3. 1. Look at the next 5 photos and answer the questions about these photos on the slide that follows: Grand Canyon

  4. Grand Canyon

  5. MachteshRamon

  6. Cerro de Cristo Rey, New Mexico, rock layers in the Anapra

  7. Pen Summit, UK Madaboutmountains.com

  8. Photo Questions: What are you seeing in each of the photos? What do you think these photos represent? Make one qualitative and quantitative observation about the photos. How do you think these mountains formed? Which layer do you think is the oldest? Do you think fossils could be found in these layers? Why?

  9. Notes – 8-2.6 Index fossils and ordering of rock layers Geologists study Earth's history by studying the record of past events that is preserved in the rocks relative agemeans the age of one object compared to the age of another object. Relative age does not tell the exact age of an object.

  10. The relative age of rocks and fossils can be determined using two basic methods: ordering of rock layers and index fossils • Ordering of Rock Layers • Scientists read the rock layers knowing that each layer is deposited on top of other layers. • The law of superpositionstates that each rock layer is older than the one above it. • the relative age of the rock or fossil in the rock is older if farther down in the rock layers. • Relative dating can be used only when the rock layers have been preserved in their original sequence.

  11. Index Fossils • Index Fossils • Certain fossils, called index fossils, can be used to help find the relative age of rock layers. • To be an index fossil 1. An organism must have lived only during a short part of Earth’s history 2. Many fossils of the organism must be found in rock layers; 3. The fossil must be found over a wide area of Earth; 4. the organism must be unique.

  12. Index Fossils

  13. Index Fossil Facts The shorter time period a species lived, the better an index it is. Example of Index fossil is a trilobites, group of hard-shelled animals body had three sections, lived in shallow seas, and became extinct about 245 million years ago. if a trilobite is found in a particular rock layer, it can be compared with trilobites from other layers to estimate the age of the layer in which it was found. Fossils that are found in many rock layers, therefore living long periods of time, do not qualify as index fossils.

  14. trilobites

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