Geological History of Gondwanaland and
Late Paleozoic Life

• 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.

Making Pangea
Convergence of Laurasia and Gondwanaland

Gondwana Reconstruction by DuToit (1927
Correlating the Permo-Triassic Gondwana Orogen

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

Late Paleozoic Gondwana Stratigraphy
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

Late Paleozoic Glaciation of Gondwana
Carboniferous
Dwyka Tillite
Glacial Striations
Permian
Dropstone

Jurassic Basalts Cap Gondwanan Sequence
Marking the Break-up
Karoo basalts, South Africa
Ferrar Dolerite Sills, Antarctica

Glossopteris Flora unique to the
Gondwanan Continents
Seed fern that liked cool swampy areas compared to the tropical
Lycopsids

The Permo-Triassic Reptiles of Gondwana
Mesosaur
A freshwater fisheating reptile

Paleogeography and Paleoclimate of Pangea
Permian ~250 Ma

Paleogeography and Paleoclimate of
Pangea

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

Paleophytic  Mesophytic
Plant Transition in Mid-Permian driven by more arid climates
Seedless Vascular Spore-bearing Plants
(Silurian-mid Permian)
Seed-bearing Gymnosperm Plants
(mid-Permian – mid-Cretaceous)

Late Paleozoic Land Animals
Arthopods, Amphibians and Anthracosaurs, Oh My!
Anthracosaurs
Amphibian -Reptile Missing Link

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

The Great Permo-Triassic Extinction
90-95% of all marine species die out, and land life too
Proposed Causes
- Global cooling due to
Gondwana glaciation
- Reduced marine habitat due to the creation of Pangea
- Extreme climatic changes
- Oxygen depletion due to exposure of coal deposits
- Upwelling of CO
2 from deep ocean waters – hypercapnia
- Intense outpouring of basalt in Serbia
NO EVIDENCE OF A METEOR
IMPACT AT LEAST!

Summary of Late Paleozoic Biologic and Geologic Events

Second Mid-term
Kate will proxy