1. MR. NEAL 2 ND /3 RD HOUR The Pre-Cambrian Earth

2. Features of the Pre-Cambrian(Basic Information) The Pre-Cambrian is the majority of Earth’s history Life first appeared 2.5 billion years ago The Earth did not cool enough for land to form for 700 million years after it formed The Pre-Cambrian saw the creation of the first rocks and continents

3. Changes in Climate Water cooled and collected into the first oceans Land did not exist as we know it today Eventually high amount of carbon dioxide from volcanoes were used by the first life for photosynthesis Photosynthesis added the first significant amount of oxygen to the atmosphere Lots of meteorite impacts

4. Types of Life Mostly single celled-organisms Eventually colonies of slime and algae began to specialize depending on their location

5. Geography Little to no land at times Volcanoes were everywhere Atmosphere had a higher concentration of sulfur which made highly corrosive acid-rain

6. Pre-Cambrian Rock Layers Several sequences including the oldest dated rock on the planet

7. Pre-Cambrian Fossils Stromatolites Bacterial colonies

8. Interesting Facts No specialized life forms just algae, slime, bacteria, and viruses Chaotic and desolate environment Oxygen was not abundant until photosynthesis added it Too much oxygen lead to “rusting” of the oceans

9. What type of environment was Northern Arizona? Underwater for most of the period Grand Canyon metamorphic rocks

10. Sources National Geographic; http://science.nationalgeographic.com/science/prehistoric- world/precambrian/ http://science.nationalgeographic.com/science/prehistoric- world/precambrian/ Michigan State University-Department of Geology; http://web2.geo.msu.edu/geogmich/Precambrian.html http://web2.geo.msu.edu/geogmich/Precambrian.html Wikipedia; http://en.wikipedia.org/wiki/Precambrianhttp://en.wikipedia.org/wiki/Precambrian Google Images; http://www.google.com/search?q=precambrian&safe=active &es_sm=93&source=lnms&tbm=isch&sa=x&ei=jztfvlpoj- mdiwk9pydacq&ved=0cagq_auoaq&biw=1280&bih=699&sur l=1#imgdii=_ http://www.google.com/search?q=precambrian&safe=active &es_sm=93&source=lnms&tbm=isch&sa=x&ei=jztfvlpoj- mdiwk9pydacq&ved=0cagq_auoaq&biw=1280&bih=699&sur l=1#imgdii=_