The Four Major Geological Eras
Precambrian Era (began 4600 million years ago and ended 570 million years ago)
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Earliest life
The time between the birth of the planet and the appearance of complex forms of life.
Makes up approximately 87% of the world’s history
Many cycles of mountain building and erosion
The only part of Canada that existed was the Canadian Shield
There were many process taking place such as folding and faulting which contributed to
mountain formation
First single and multi – celled organisms
Paleozoic Era (began 570 million years ago and ended 245 million years ago)
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325 million years long
Sediment was compressed into sedimentary rock – bedrock
North America was located near the equator – swamps formed ( these
vegetative swamps eventual lead to the creation of coal
With the collision of continents eastern North America crumpled up forming the
Appalachian Mountains
Age of amphibians and fish
First insects
First plants and animals appeared on land
Mesozoic Era (began 245 million years ago and ended 66 million years ago)
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Lasted 180 million years
Dinosaurs lived in this era – age of the reptile
Formation of Rocky Mountains begins and Innuitian Mountains completed
Shallow seas in the interior of North America at various times
First flowering plants
First birds and mammals
The breakup of Pangaea began and lasted 200 million years
The landform that now create Canada and the US were still very warm therefor
dinosaurs roamed here
Vegetative swamps were covered by sand and silt
The end of the era was marked by a mass extinction – more than half of all the plant
and animal species, including the dinosaurs, became extinct.
Cenozoic Era (began 66 million years ago up to present time)
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Ice sheets covering most of North America (Ice Age)
Contents took present shape – land masses were carved out by the movement of
the glaciers – This geological procedure had a huge impact on Canada’s geography.
Age of mammals – human beings develop
Human beings have had a huge impact on the world considering the short time we
have been here.