1 / 139

GEOL 240 The Dinosaurs: Origin of Life and Fossil Record

GEOL 240 The Dinosaurs: Origin of Life and Fossil Record. Summary. Introduction to Plate Tectonics. Plate Tectonics. Relatively new theory - introduced about 30 years ago Unifies several branches of the Earth Sciences http://pubs.usgs.gov/publications/text/dynamic.html.

gray-gould
Télécharger la présentation

GEOL 240 The Dinosaurs: Origin of Life and Fossil Record

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. GEOL 240 The Dinosaurs:Origin of Life and Fossil Record

  2. Summary • Introduction to Plate Tectonics

  3. Plate Tectonics • Relatively new theory - introduced about 30 years ago • Unifies several branches of the Earth Sciences • http://pubs.usgs.gov/publications/text/dynamic.html

  4. In 1858, geographer Antonio Snider-Pellegrini made these two maps showing his version of how the American and African continents may once have fit together, then later separated.

  5. Alfred Lothar Wegener • Developed the Theory of Continental Drift • Published “Die Entstehung der Kontinente und Ozeane” in 1915

  6. BUT - • NO MECHANISM !!!

  7. Mid-Ocean Ridges

  8. Seafloor Spreading

  9. Paleomagnetism

  10. Magnetic Striping

  11. Continental Drift +Seafloor Spreading +A few refinements = PLATE TECTONICS

  12. All Plates are surrounded bya combination of three differenttypes of boundaries • Divergent • Convergent • Transform

  13. Divergent Boundary

  14. Mid-Ocean Ridges

  15. Continental Rift Systems

  16. Convergent Boundary • Three Types • Ocean-Ocean Collision • Continent-Ocean Collision • Continent-Continent Collision

  17. Ocean-Ocean Collision

  18. Ocean-Continent Collision

  19. Continent-Continent Collision

  20. Transform Boundry

  21. Satellite measurements of plate movement

  22. Formation and Differentiation of the Earth

  23. Hadean and Archean Eons

  24. Archean (until 2.5 BYA) • Atmosphere composed of methane, ammonia, hydrogen and very little oxygen • Very primitive life – bacteria and stromatolites (3.4 –3.5 billion years ago) - prokaryotes • Cratons of significant size begin to form approximately 3 billion years ago

  25. Prokaryotes • individuals (not colonial) • single celled • no nucleus • no partitions • Originally heterotrophic (ate others)

  26. Autotrophs (organisms capable of creating their own food i.e. photosynthesis) appeared about 2 bya. • Originally referred to as blue-green algae they are actually closer to bacteria and are photosynthetic prokaryotes

  27. stromatolites

  28. Proterozoic • EON • Moderate levels of • oxygen in the atmosphere • were reached about • 2 billion years ago • Oldest multicellular life • ~1.3 bya • Stable continents form

  29. Eukaryotic Organisms • evolved ~1.7 bya • have nucleus and internal chambers called organelles w/ specific functions • unicellular, colonial or multicellular • Introduction of Sexual Reproduction ! • Multicellular “animal” life evolved ~670 Mya

More Related