1 / 21

Petrified Remains

Petrified Remains. Hard and rock like Original material replaced by minerals Ex. bones, wood. Carbonaceous Films. Burial forces gases and liquid out Forms thin film of carbon residue Outline of organism Ex. plants. Mold & Cast. Organism is buried Outside decays leaves a

cassady-beasley
Download Presentation

Petrified Remains

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Petrified Remains • Hard and rock like • Original material replaced by minerals • Ex. bones, wood

  2. Carbonaceous Films • Burial forces gases and liquid out • Forms thin film of carbon residue • Outline of organism • Ex. plants

  3. Mold & Cast • Organism is buried • Outside decays leaves a cavity = mold • Sediment fills in mold and hardens to rock = cast The cast looks like the organism!

  4. Original Remains • actual or part of organism • trapped in Amber – insects • frozen – woolly mammoth • tar pits

  5. Los Angeles La Brea Tar Pits This is a recreation of a tar pit that illustrates how animals would get trapped in tar pits. • What is a tar pit???

  6. Trace Fossils • evidence of animal activity • tells how organism lives • Ex. tracks, worm holes Worm tracks! ↓ These are dinosaur foot prints!!

  7. Index Fossils • Used to date other fossils and rock layers. • Fossils of animals that • Existed for a short period of time • Were abundant, there were many of them • Lived all over the world EUOMPHALUS But wait…. There’s more…. TRILOBITE

  8. Finding Clues to Rock Layers Activity!!! You be the dective!

  9. You be the Detective! • Fossil clues give geologists a good idea of what life on earth was like millions or even billions of years ago! • Problem: How can YOU use fossils and geologic features to interpret the relative ages of rock layers?

  10. 1. What “fossil clues” in layers A and B indicate the kind of environment that existed when these rock layers were formed? How did the environment change in layer D? • Fossils of marine animals in A and B • In layer D – Dinosaur tracks and a leaf = land

  11. 2. Which layer is the oldest? How do you know? • A is the oldest because the law of Superposition states that the lowest layer is the oldest.

  12. 3. Which of the layers formed most recently? How do you know? • Layer G formed most recently because the law of superposition states that the highest layer is the youngest.

  13. 4. Why are there no fossils in layers C and E? • Layers C and E are extrusions of igneous rock (igneous rocks do not contain fossils)

  14. 5. What kind of fossils occurred in layer F? • Dinosaur, Plant, and bird fossils

  15. Site 26. Which layer at Site 1 might have formed at the same time as layer W at Site 2? How do you know? • Layer B • Have the same type of fossils!

  16. 7. What clues show an unconformity or gap in the horizontal rock layers? What might have happened to these rock layers? • Rock layers that are missing from the sequence - Site 2 provide clues of an unconformity. • Layers E and D are missing between layers X and Y, which suggests an unconformity. • Layer A is also missing, which suggests an unconformity below W. • So…Erosion might have occurred because there are missing layers in site 2!

  17. 8. Which is older, intrusion V or layer Y? How do you know? • Layer Y is older • An intrusion is always younger that the layers it passes through

  18. 9. Working as a geologist, you find a rock containing fossils. What information would you need in order to determine the rock’s age relative to one of the rock layers at Site 1? • You would need to know if any layers at Site 1 contained the same index fossils.

More Related