1. EARLY PALEOZOIC EVENTS ORDOVICIAN PALEOGEOGRAPHY Cratonic Sequences of
North American

2. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOGEOGRAPHY

4. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOGEOGRAPHY

6. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOGEOGRAPHY
Queenston Clastic
Wedge

7. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOGEOGRAPHY

8. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOGEOGRAPHY
Millburg Volcanic Ashes - Pennsylvania

9. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOGEOGRAPHY

10. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOGEOGRAPHY
Subduction initiated on west coast NA
Greywackes and volcanics accumulate

11. EARLY PALEOZOIC EVENTS ORDOVICIAN PALEOGEOGRAPHY Other Tectonic Events
Ouachita Trough

12. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOGEOGRAPHY
Other Tectonic Events
Williston Basin

13. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOGEOGRAPHY
Other Tectonic Events
Williston Basin

14. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOGEOGRAPHY
Other Tectonic Events
Williston Basin

15. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOGEOGRAPHY
Other Tectonic Events
Williston Basin

16. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOGEOGRAPHY
Other Tectonic Events
Williston Basin
Evaporites
Red River
Formation

17. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOGEOGRAPHY

18. EARLY PALEOZOIC
EVENTS
ORDOVICIAN
PALEOCLIMATE

19. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOCLIMATE

20. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOCLIMATE

21. EARLY PALEOZOIC EVENTS
ORDOVICIAN PALEOCLIMATE
From the Early to Middle Ordovician, the earth experienced
a milder climate in which the weather was warm and the
atmosphere contained a lot of moisture.
However, when Gondwana finally settled on the South Pole
during the Late Ordovician, massive glaciers formed
causing shallow seas to drain and sea levels to drop.
This likely caused the mass extinctions that characterize the
end of the Ordovician, in which 60% of all marine invertebrate
genera and 25% of all families went extinct.