Earth History GEOL 2110

1. Earth History GEOL 2110 The Paleozoic Era Part 5b: Geological History of Gondwanaland and Late Paleozoic Life

2. Major Concepts • The continental reconstructions of Gondwana by Werner and DuToit were bang on and confirmed by geologic mapping, paleomagnetism, biostratigraphy, and paleogeography. • The supercontinent of Gondwana, composed of South America, Africa, Australia, India, and Antarctica, was together for most of the Paleozoic and situated in the high latitudes of the southern hemisphere. • Floral and faunal assemblages of Gondwana were very distinct from the northern landmasses (Laurasia) • The Permo-Triassic extinction devastated marine life and to a lesser extent, land-based plants and animals. The cause of this greatest of all extinctions is still unclear.

3. Events of the Late Paleozoic Era

4. Making PangeaConvergence of Laurasia and Gondwanaland

5. Wegner’s Pangea (1927)

6. Gondwana Reconstruction by DuToit (1927Correlating the Permo-Triassic GondwanaOrogen

7. Paleomagnetism Confirms Gondwana Continent Reconstructions From Bullard, 1965 Apparent Polar Wander Paths for SA and Africa Best-fit of curves imply that SA, Africa & Australia (& Antarctica) have been together near the South Pole since late Cambrian

8. Current Reconstruction

9. Late Paleozoic GondwanaStratigraphy Dominated by non-marine sediments and tillites Made it difficult to correlate with European strata based on marine fossils Capped by Jurassic-Cretaceous basalts – Break-up

10. Late Paleozoic Glaciation of Gondwana Carboniferous DwykaTillite Glacial Striations Permian Dropstone

11. Jurassic Basalts Cap Gondwanan SequenceMarking the Break-up Karoo basalts, South Africa Ferrar Dolerite Sills, Antarctica

12. Glossopteris Flora unique to the Gondwanan Continents Liked cool swampy areas compared to the tropical Lycopsids

13. The Permo-Triassic Reptiles of Gondwana MesosaurA freshwater fish-eating reptile

14. Paleogeography and Paleoclimate of Pangea Permian ~250 Ma

15. Paleogeography and Paleoclimate of Pangea

16. Paleogeography and Paleoclimate of Pangea Strong Latitudinal Zoning of Climate Tethys Sea Liehl and Shields, 2005, Geology

17. Paleophytic MesophyticPlant Transition in Mid-Permiandriven by more arid climates Seedless Vascular Spore-bearing Plants (Silurian-mid Permian) Seed-bearing Gymnosperm Plants (mid-Permian – mid-Cretaceous)

18. Late Paleozoic Land AnimalsArthopods, Amphibians and Anthracosaurs,Oh My! Anthracosaurs Amphibian -Reptile Missing Link

19. Amniotes Arrive in Mid-CarboniferousThe Evolution of Eggs with Amniotic Membrane leads to Reptiles, Birds and Mammals Dimitrodon Hyolnomus

20. The Great Permo-Triassic Extinction90-95% of all marine species die out, and land life too • Proposed Causes • - Global cooling due to • Gondwanaglaciation • Reduced marine habitat due • to the creation of Pangea • Extreme climatic changes • Oxygen depletion due to • exposure of coal deposits • Upwelling of CO2 from deep • ocean waters – hypercapnia • Intense outpouring of basalt • in Serbia • NO EVIDENCE OF A METEOR IMPACT AT LEAST!

21. Summary of Late Paleozoic Biologic and Geologic Events

22. FRIDAY • Mid-term on Chapters 8-13 • 25% Multiple Choice from Quizzes • Focus on Figures and Figure Captions • Chapter Summaries • PowerPoints