1 / 45

GEOLOGY – EARTH’S STORY

GEOLOGY – EARTH’S STORY. Lesson 1. “The Present is the Key to the Past” - By geologist James Hutton, late 1700’s. Copy this statement into your notebook. Then write a few sentences about how studying the present could reveal the story of earth’s history. Catastrophism.

hallhelen
Download Presentation

GEOLOGY – EARTH’S STORY

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. GEOLOGY – EARTH’S STORY Lesson 1

  2. “The Present is the Key to the Past”- By geologist James Hutton, late 1700’s Copy this statement into your notebook. Then write a few sentences about how studying the present could reveal the story of earth’s history.

  3. Catastrophism • A Principle that states that all geological change occurred suddenly. • Catastrophes happened- Rare, sudden, events, for e.g. Earthquakes, The Noachian flood, Tsunamis, Mudslides, Creation?

  4. Uniformitarianism • In 1795 by philosopher/scientist James Hutton • Wrote that earth’s landforms were constantly and gradually changing

  5. Hutton observed… • Natural forces breaking down rock… • Rivers carry rock particles downstream… • Deposition of sediments, forming new layers. Eventually forming new rock… • He thought new rock will eventually be uplifted – or from volcanoes – creating new landforms. • The cycle will start over again. • He judged from the slowness of the processes that Earth must be incredibly old!

  6. Uniformitarianism is a Principle that states that the same geological processes shaping the earth today have been constantly, slowly, and gradually, at work, throughout earth’s history

  7. Charles Lyell • In 1830 published a book, “Principles of Geology” • Was a friend of Hutton • and of Charles Darwin, and was influenced by Darwin’s theory of Evolution.

  8. The great Debate! • A HAPPY MEDIUM  • Most modern scientists believe both principles are at work in nature

  9. Most geological change is gradual e.g. erosion • Catastrophic events do happen e.g. earthquakes

  10. Example: An asteroid impacting the Earth is believed to have led to dinosaur extinction • Tsunami in Japan, 2012 • Earthquake in Chile, 2015 • More?

  11. Activities A. Apply – Do the Making Assumptions activity. Work with your seat partner! B. 1. Why do Earth scientists need the Principle of Uniformitarianism in order to make predictions? • Compare and Contrast Uniformitarianism and Catastrophism?

  12. Relative Dating: “Which Came First?” Section 6-2

  13. What is Relative Dating? Relative Dating uses a number of Principles or Laws • Compare one rock layer to another to determine if one is older or younger • Does NOT give specific age of rock.

  14. Laws/Principles used are: • The Law of Uniformitarianism • The Law of Catastrophism • The Law of Superposition • The Law Inclusions • The Law of Cross-Cutting • Principle of Original Horizontality • Unconformities, and Disturbances,

  15. The Principle of Superposition top younger rocks bottom older

  16. The Geological Column • What is it? • What is it used for? • Dating rocks – by make comparisons • Identifying layers in puzzling or disturbed rock sequences

  17. Younger rocks lie above older rocks in undisturbed sequences “Younger over older”

  18. Disturbancescaused by forces within the earth • Intrusion - • Fault - • Tilting - • Folding -

  19. Law of Intrusion or Cross-Cutting • Anything cutting across a rock layer is younger. The rock had to be there first! • Cross cuts can be • Igneous Intrusions, or • Igneous Extrusions, or • Faulting (earthquakes)

  20. Intrusion – cross-cutting Is the dike the youngest or oldest?

  21. A diabase dike crosscutting horizontal limestone beds in Arizona

  22. Faults Go To: http://www.uwgb.edu/dutchs/earthsc202notes/quakes.htm

  23. Tilting

  24. Folding

  25. Fault across Fold

  26. Law of Inclusions • Pieces of rock found in other layers are always older

  27. Inclusions Which came first, the ant or the amber?

  28. If a rock (Rock B) contained fragments of another rock body (Rock A), B must be younger than the fragments of rock A it contained. The intruding rock (Rock A) must have been there first to provide the fragments.

  29.  Activities  • P138 Activity with text chapters on note-cards. • Construct the Geological Column using cutouts.

  30. UnconformitiesGaps in the record • Is a surface that represents a missing part of the geological column – show missing time. • Gaps caused by erosion

  31. Types: • Nonconformities • Disconformities • Angular Unconformities

  32. Nonconformity Grand Canyon overlying sedimentary rocks Missing eroded layers igneous/metamorphic rocks below the nonconformity

  33. At Corrie, England, the red rocks are early Permian, and they lie unconformably, and at a slight angle, on greyer rocks of Carboniferous age.

  34. Angular Unconformity

  35. Disconformity

  36. Disconformity - A disconformity is an unconformity between parallel layers of sedimentary rocks which represents a period of erosion or non-deposition. A Nonconformity - exists between sedimentary rocks and other rocks when the sedimentary rock lies above and was deposited on the pre-existing and eroded metamorphic or igneous rock.

  37. Nonconformities continued An angular unconformity is an unconformity where horizontally parallel strata of sedimentary rock are deposited on tilted and eroded layers

  38. Hmwk  • Complete Text Qus. • Worksheet • Prepare for Quiz

  39. View • Discovery Education Video: “Rocks of Ages”

More Related