Geological History of Canada

4.6 Billion Years Ago

Precambrian 

Beginning of the Precambrian

The Precambrian began with the earth's formation and lasted around 4 billion years. The geological processes of the Precambrian saw the creation of the earth’s crust and the oceans. Life began on Earth during this period, going from the earliest single-celled organisms to early bacteria and algae (e.g., stromatolites) to the first multicellular organisms.

3.48 Billion Years Ago

Precambrian 

Earliest Known Life on Earth

While there is some evidence of life on Earth as early as 4.1 billion years ago, 3.48-billion-year-old stromatolite fossils in western Australia are the oldest undisputed direct evidence of life on Earth.

3.18 Billion Years Ago

Precambrian 

Beginning of the Formation of the Supercontinent Arctica

Arctica was one of the ancient continents that makes up much of what is now Canada, especially the Canadian Shield area in Labrador, Quebec, Ontario, Manitoba, Saskatchewan, Alberta, Northwest Territories and Nunavut. This land mass was formed between 2.5 and 1.9 billion years ago but originated from several older Archaean microcontinents that came together. Some of the rocks in these microcontinents are as old as 3.18 billion years.

1.8 Billion Years Ago

Precambrian 

Formation of the Supercontinent Nena

Around 1.8 billion years ago, several other microcontinents were welded to Arctica. This resulted in a new supercontinent known as Nena, which is an acronym for Northern Europe and North America.

1.3 Billion Years Ago

Precambrian 

Formation of the Supercontinent Rodinia

Rodinia, another ancient supercontinent, began forming around 1.3 billion years ago when the Grenville microcontinent connected with Nena. These land masses coming together resulted in the formation of the Grenville Mountains. Some remnants of the Grenville Mountains remain visible in North America, such as in the Appalachian and Adirondack mountains of eastern North America. As Rodinia was taking shape, massive mountains comparable to the Himalayas today were forming elsewhere around the world.

1.1 Billion Years Ago

Precambrian 

Breakup of the Supercontinent Nena

Between 1.1 and 1.0 billion years ago, a mid-continental rift formed in the Nena land mass as the continent nearly split. This 2,000 km long, 20 km deep chasm is now filled with intrusive, volcanic and sedimentary rocks. In Canada, the remains of this rift are found near Lake Superior.

700 Million Years Ago

Precambrian 

Breakup of the Supercontinent Rodinia

Rodinia begins to break apart into smaller continents over millions of years. One of these continents that would later form Canada was Laurentia. Vast regions of Laurentia in what is now eastern Canada were covered by a shallow, warm ocean that was full of early marine life. This resulted in sedimentary deposits in the area, which are now known as the Paleozoic Cover Sequence or the Laurentian Platform. At this same time, over millions of years, the Grenville Mountains slowly eroded.

541 Million Years Ago

Precambrian 

End of the Precambrian

Ends of supereons, eons, eras and periods are often marked by major changes in geology, climate or organism diversity, sometimes culminating in extinction events. The Precambrian eons account for about 90 per cent of the history of the Earth to date. These eons saw increasing amounts of oxygen in the atmosphere as early cyanobacteria began photosynthesis and much tectonic activity. The Precambrian ended with the evolution of the first animals.

541 Million Years Ago

Cambrian 

Beginning of the Cambrian

The beginning of the Cambrian Period is also the beginning of the Paleozoic Era. The Cambrian Period is characterized by the Cambrian explosion, in which animals spread and diversified in the earth’s oceans and seas, especially along coastlines. Hard-shelled sea creatures became commonplace. Early arthropods and chordates also evolved. During much of this time, extensive seas covered swaths of the Laurentian Platform, covering much of the east and west coasts of what would become Canada.

485 Million Years Ago

Cambrian 

End of the Cambrian – Cambrian Extinction

A series of extinctions characterize the end of the Cambrian. These extinctions wiped out many marine organisms. Various factors may have led to these extinctions, such as volcanic activity, low oxygen levels in the oceans and changes in sea level. The boundaries between periods are often marked in rock strata at a place where the rock characterizes the differences between said periods, called the Global Boundary Stratotype Sections and Points (GSSP). The GSSP for the beginning of the Cambrian is in Fortune Head, Newfoundland.

485 Million Years Ago

Ordovician 

Beginning of the Ordovician

The Ordovician Period saw the evolution and diversification of many important species of invertebrates, land plants and armoured fish. During this period, much of what would become Canada was covered by ocean, save for areas of the Canadian Shield and Hudson Bay Lowlands, as well as what would become the Maritimes.

443 Million Years Ago

Ordovician 

End of the Ordovician - Late Ordovician Mass Extinction Event (LOME)

The end of the Ordovician Period is characterized by a mass extinction that killed up to 86 per cent of all species. This period of mass extinction took place over around 2 million years. Some theories about the cause of this mass extinction include a cooling climate, glaciations and changes in the ocean’s oxygen levels.

443 Million Years Ago

Silurian 

Beginning of the Silurian

During the Silurian Period, sea levels were high and continental land masses were low. As a result, there were many warm, shallow seas teeming with life, especially in what is now North America. Jawless fish, like modern hagfishes and lampreys, were common. This period also saw extensive reef building and life spreading to freshwater ecosystems. Terrestrial ecosystems were also beginning to form, with lichens, arthropods (e.g., millipedes and spiders) and mosses leading the way. During this time, the supercontinent of Gondwana covered much of the southern hemisphere.

419 Million Years Ago

Silurian 

End of the Silurian

The Silurian ended as terrestrial life, especially plant life, rapidly diversified, leading directly into the Devonian Period. This period does not end with a major extinction event; instead, it is marked by a species of graptolite (a colonial invertebrate) showing up in the fossil record. The presence of different species of graptolites in the fossil record are often used to mark the boundaries between time stages.

419 Million Years Ago

Devonian 

Beginning of the Devonian

The Devonian Period saw an explosion of life on land, especially as plants began to evolve rapidly. In the oceans, fish continued to diversify; the Devonian is often called the “Age of Fishes.” Though the landscape of what would become North America had large underwater portions, much of the east coast was terrestrial and part of the Laurasia supercontinent. Many terrestrial landscapes during this period saw great changes, including the first fish crawling onto land, such as Tiktaalik, which was found in Ellesmere Island, Nunavut. Other changes around the globe included the first forests of early conifer-like trees. Trees profoundly impacted the entire planet, changing the earth’s climate, atmospheric oxygen levels and even oceanic nutrient cycling.

358 Million Years Ago

Devonian 

End of the Devonian – Late Devonian Extinction

A series of extinction events resulted in the death of at least 70 per cent of the species on Earth, marking the end of the Devonian Period. This period is considered one of the big five mass extinction events. The widespread impacts of the evolution of land plants may have led to this mass extinction. Changes in marine nutrient cycling led to algal blooms, rendering many ocean regions anoxic.

358 Million Years Ago

Carboniferous 

Beginning of the Carboniferous

The Carboniferous Period was a golden age for plants. This lush period was filled with dense forests of early conifer-like trees, mosses, ferns and horsetails. Amphibians and insects were widespread. Over time, the massive amount of swamp forests led to the formation of 90 per cent of the world's coal deposits, such as the deposits found today in the Appalachian regions of the Maritime provinces. In the oceans of the carboniferous, sharks dominated. Dryer regions allowed the evolution of the first amniotic egg and, consequently, the first reptiles.

320 Million Years Ago

Carboniferous 

Formation of the Supercontinent Pangea

The famous supercontinent of Pangea formed as the supercontinents Gondwanaland and Laurasia merged.

298 Million Years Ago

Carboniferous 

End of the Carboniferous - Carboniferous Rainforest Collapse (CRC)

The end of the Carboniferous is characterized by an extinction event known as the Carboniferous Rainforest Collapse (CRC).  The later part of the Carboniferous experienced glaciation, changes in sea levels and climate change. As a result, many of the rich swamp forests disappeared.

298 Million Years Ago

Permian 

Beginning of the Permian

During the Permian, reptiles began to diversify, eventually giving rise to dinosaurs and mammals alike during the Triassic. During this period, the eastern half of present-day North America was part of the supercontinent Pangea, while shallow seas and islands covered the west coast.

252 Million Years Ago

Permian 

End of the Permian – Permian Triassic Extinction Event (PTEE)

The Permian Period ended with a mass extinction known as the Permian Triassic Extinction Event (PTEE), in which over 90 per cent of all species disappeared. This mass extinction, the worst Earth has seen to date, is also known as the “great dying” and nearly ended all life on Earth. The exact cause of this mass extinction remains debated, though various natural catastrophes occurred around the same time, possibly explaining the massive loss of life. A runaway greenhouse effect began with a cataclysmic volcanic eruption that blasted CO₂ into the atmosphere. Methane, another greenhouse gas, was released by bacteria. Temperatures increased and the oceans acidified. Among the species lost were the trilobites, who had first appeared in the Cambrian and survived prior mass extinctions. The end of the Permian Period also marked the end of the Paleozoic Era.

252 Million Years Ago

Triassic 

Beginning of the Triassic

It took millions of years for life to recover from the Permian extinction. During the Triassic, life began to diversify once more. This period saw the first dinosaurs, mammals and flying reptiles. The beginning of the Triassic Period was also the beginning of the Mesozoic Era.

201 Million Years Ago

Triassic 

End of the Triassic

A mass extinction marked the end of the Triassic. During this mass extinction, 80 per cent of species were lost. The exact cause of this mass extinction remains unknown.

201 Million Years Ago

Jurassic 

Beginning of the Jurassic

One of the most famous periods in Earth’s history, the Jurassic saw large dinosaurs dominate the land.

200 Million Years Ago

Jurassic 

Breakup of Pangea

During the Jurassic, Pangea began to break up, splitting along what is now the Atlantic coast. As this rift formed, it was filled with water, creating the Atlantic Ocean. The Atlantic Ocean pushed North America westward, where it collided with various microcontinents. This collision resulted in the Cordilleran Orogeny, from which a precursor to the Rocky Mountains was formed.

150 Million Years Ago

Jurassic 

Formation of the Western Interior Seaway

The Western Interior Seaway began to form near the end of the Jurassic and lasted tens of millions of years. This sizeable inland sea split the continent of North America into two separate landmasses (Appalachia and Laramidia), connecting the Arctic Ocean to the Gulf of Mexico. At its maximal size, the Western Interior Seaway was 2,000 km wide, 600 m deep and over 5,000 km long.

145 Million Years Ago

Jurassic 

End of the Jurassic

The end of the Jurassic is difficult to define, as it is not marked by a major extinction event.

145 Million Years Ago

Cretaceous 

Beginning of the Cretaceous

The Cretaceous saw the evolution of the first flowering plants. Dinosaurs continued to evolve, with famous species such as Tyrannosaurus rex roaming the Cretaceous. This period also saw the evolution of the first placental mammals. During this period, tectonic activity in western North America, known as the Servier Orogeny, contributed to the formation of the Rocky Mountains.

66 Million Years Ago

Cretaceous 

End of the Cretaceous and K-Pg Boundary

The Cretaceous ended in a mass extinction following an asteroid impact. This famous mass extinction wiped out 76 per cent of all species, including all non-avian dinosaurs and pterosaurs. Volcanic activity and climate change may have already weakened many species prior to the asteroid impact. The end of the Cretaceous Period was also the end of the Mesozoic era.

66 Million Years Ago

Paleogene 

Beginning of the Paleogene

The Paleogene saw the further evolution of birds. Though birds had evolved by the late Cretaceous, it was not until after the extinction of the non-avian dinosaurs that birds began to diversify extensively. At the same time, mammals began to increase in size. Notably, the first primates evolved. This period also saw tectonic activity along western North America in the form of the Laramide Orogeny, which further contributed to the formation of the Rocky Mountains. The beginning of the Paleogene Period also marked the beginning of the Cenozoic Era.

56 Million Years Ago

Paleogene 

Western Interior Seaway Disappears

After tens of millions of years, the Western Interior Seaway gradually disappeared following a regional uplift and the continued mountain-building on the western side of North America. The Cannonball Sea, a Cenozoic Era remnant of the Western Interior Seaway, represents the last marine incursion into the western interior of North America, likely sometime between 56 and 66 million years ago.

23 Million Years Ago

Paleogene 

End of the Paleogene

The Paleogene ended with a period of significant global change and an extinction event. Oceanic and atmospheric circulation patterns changed due to the Paleocene-Eocene Thermal Maximum, resulting in the extinction of certain species.

23 Million Years Ago

Neogene 

Beginning of the Neogene

The Neogene saw the evolution of many modern birds and mammals. This period also saw the first upright-walking ancestors of humans, living in Africa. In certain areas, grassy ecosystems became widespread (see Prairie).

2 Million Years Ago

Neogene 

End of the Neogene

As the end of the Neogene approached, Earth experienced a global climate cooling. This led into the ice ages of the Quaternary.

2 Million Years Ago

Quaternary 

Beginning of the Quaternary

Much of the Quaternary is characterized by a long Ice Age broken up by warmer phases. About 315,000 years ago, modern humans evolved in Africa and began to spread worldwide. This period also saw the extinction of mammal and bird megafauna such as mammoths.

19,000 Years Ago

Quaternary 

Last Glacial Maximum in North America

North America experienced its last glacial maximum between 23,000 and 19,000 years ago. During this time, most of what is now Canada was covered by the Laurentide Ice Sheet, which was as much as 4 km thick in some areas. As it retreated, forests and wildlife followed, resulting in a landscape similar to today's.