1. Chapter 1: The Abyss of Time
1.2 Early Life
Chapter 1: The Abyss of Time

2. Cameron Falls Outcrop of Alberta’s oldest sedimentary rock
The properties of this sedimentary rock and its fossils provide evidence of the environment 1.5 billion years ago
There is evidence that Alberta bordered an ANCIENT OCEAN where large rivers deposited layers of sand, clay and silt

3. Single-celled Bacteria
Life Gets its Start
The world’s oldest evidence of life dates back 3.8 billion years
Life may have existed before that but there is NO FOSSIL evidence
Earliest life forms
Single-celled Bacteria

4. Hot Oceans Early Earth did not have an environment to support life
Frequent volcanic eruptions
Poisonous gases (methane, hydrogen sulfide)
Oceans were more than 100 C
Atmosphere had little oxygen
Extreme bacteria-like organisms (archaea) were able to tolerate this environment

5. A Breathable Atmosphere
1.5 billion years ago…
Cyanobacteria was able to thrive, growing and dying in layers
As they layered they deposited large mounds of calcium carbonate (limestone) called stromatolites
Stromatolites are Alberta’s oldest fossils
Cyanobacteria were one of the only early producers of oxygen through photosynthesis
Cyanobacteria was the dominant form of life for 2 billion years!

6. Stromatolites

7. Snowball Earth Late Precambrian….
Icecaps covered most of the planet for almost 10 million years
Evidence of glaciers advancing and retreating are found all over the world
Changes in habitat during the freezing the thawing lead to a great increase in biodiversity and the first complex organisms