1. Earth History

2. Sections 1. Precambrian Earth 2. Paleozoic Era 3. Mesozoic Era
4. Cenozoic Era

3. Precambrian Earth

4. Geologic Time Scale Geologic Time Scale
The geologic time scale is a record of Earth’s History
The Earth is 4.6 Billion Years Old
Precambrian (4.6 bya – 543 mya)
Paleozoic Era (543 mya – 250 mya)
Mesozoic Era (250 mya – 65 mya)
Cenozoic Era (65 mya – Present)
Geologic Time Scale

6. Origin Of Earth 4.6 Bya – Earth Formed
Solar Neblua Hypothesis – Cloud of dust and gas collapsed by the force of gravity
Formed the sun and the other planets in the solar system
4.0 Bya – Earth had a stable crust, oceans and atmosphere

7. Origin Of Life 3.8 Bya-First life forms evolved
Stromatolites – Mounds of cyanobacteria
Were photosynthetic – Consumed carbon dioxide, produced oxygen
Created Earth’s oxygen supply

8. First Continents 3.5 Bya-The first continents began to form
Convection began due to unequal heating of the mantle (plate tectonics)
Caused the landmasses to move apart

9. Atmosphere 2.5 Bya – Atmosphere became dominated by oxygen
1.8 Bya – First cells with nuclei appeared
Eukaryotes – WILL Need to know for Biology!

10. NC Mountains 1.7 Bya- Present day North Carolina formed
1.3 Bya-The first mountains of North Carolina formed
Grenville mountains (no longer exist due to erosion)
Formed by Grenville Orogeny
Oldest rocks of NC formed. Presently exposed in the Appalachian Mountains

11. First Multi-Celled Organisms
1 Bya – First multi-celled organisms
600 mya – First sponges and worm like animals appeared

12. NC Flooding 620 mya-North Carolina was pulled apart by tectonic forces
Seas covered North Carolina
Volcanic island arcs developed along NC-VA border

14. Paleozoic Era

15. Cambrian Explosion
542 mya-”Cambrian Explosion” – Major diversification of life
First vertebrates
North Carolina was still underwater

16. Rodinia
540 mya-North America and Europe/ Africa moved towards each other
Formed Kings Mountain Belt
Formed supercontinent Rodinia

19. Taconic Orogeny
mya-Taconic Orogeny: The coastline of present day Appalachian Mountains collided with Iapetus Plate (Oceanic Plate)
Formed volcanic mountains in present day North Carolina

21. Paleozoic Fish 444 mya – Fish were dominant First jawed fish
Sea scorpions
Trilobites
Mollusks
First land plants

22. Acadian Orogeny
Acadian Orogeny ( mya): A continent called Avalonia collided with present day North America
Continued the formation of the Appalachian mountains.
Also lead to the formation of Pangaea

23. Coal Forests 359 mya-Wetland forests dominated the Appalachian area
The decayed organic matter from the trees lead to coal that is currently mined today

25. Alleghanian Orogeny
Alleghanian Orogeny ( mya): Africa collided with North America.
Pangaea was fully assembled.
Appalachians were fully formed, in the center of Pangaea

28. Permian Mass Extinction
251 mya – Permian Mass Extinction
Drop in sea level, resulted in 95% of all life going extinct
Possible changes in climate
75% of amphibians, 80% of reptiles disappeared

29. Mesozoic Era

30. Appalachian Erosion 251 mya-Appalachians began to erode
Wind and rain → Sediment was carried to lower lying land or sea
Pangaea was breaking up
North Carolina was near the equator, had a tropical climate

31. Mesozoic Events
250 mya – Dinosaurs first appeared → Were dominant organisms
First mammals appeared
First crocodiles
Ichthyosaurs-Dolphin like organisms in the seas

32. Pangaea Separation
200 mya-As Pangaea separated the Atlantic Ocean formed
Outer margin became the outer banks
Atlantic Ocean began to open up

33. Mesozoic Life 200 mya- Dinosaurs were still dominant
Mammals began to grow in numbers → Still not dominant
First birds and lizards

34. Coastal Plain Flooding
145 mya-65 mya: Coastal Plains were underwater but sea level began to drop
Pangaea continued to split up
Southern landmasses broke up → Africa and South America created

36. Mesozoic Extinction
65 mya – Mass extinction: All dinosaurs went extinct
Most geologists think a meteorite hit in the Yucatan Peninsula in Mexico which caused this → Supported by presence of iridium

37. Title

38. Cenozoic Era

39. Cenozoic Life
65 mya - Mammals began to dominate. First large mammals appeared
World’s climate was tropical however was starting to cool
57 mya – Coastal Plains were now above sea level

40. First Mammals 55 mya – First modern mammals evolved
Whales diversified
Coastal Plains flooded again → Seas stretched up to the Western Piedmont

42. Modern Mammals 23 mya – Modern mammals and birds appeared
Grasses dominated the Earth
Ocean retreated from the coastal plains

44. Blue Ridge Mountains
5 mya-Blue Ridge and Piedmont were as they are today
First human ancestors
Coastal Plains were flooded again but waters receded
Sand Hills Developed – Streams eroded piedmont and sent sediment to the coastal plains
Fall Line – Sharp drop off in elevation. Located around Fayetteville

46. Ice Age 1.7 mya-”Ice Age” began. 18,000 years ago – Glaciers melted
There is present day evidence in the Coastal Plains
Glacial Till
18,000 years ago – Glaciers melted

48. Human Civilization
10,000-15,000-North Carolina’s forests began to develop
Look as they do now
9,000 BC-Human civilization began

50. Assignment
Make a timeline showing the history of the earth with each Period and Era Listed
After making the timeline, begin looking over notes and preparing to study for our Exam Wednesday