The Evolution Of The Atmosphere Flashcards
What was the earths surface originally made out of?
Molten, it was so hot that any atmosphere just ‘boiled away’ into space
What is phase 1 of the evolution of the atmosphere?
Volcanoes giving out gasses
What happened in phase 1 of the evolution if the atmosphere when earth cooled down?
A thin crust formed on the earth. However volcanos were still erupting
How is it thought that oceans were formed?
Volcanoes erupting and giving out lots of gas. The oceans then formed when water vapour condensed
How was it thought that the atmosphere was made and what was it made up of?
Volcanoes erupting and giving out lots of gasses. It was most likely made up of mostly carbondioxide with hardly any oxygen. There also may have been small amounts of water vapour, methane and ammonia
What is phase 2 of the evolution if the atmosphere?
Green plants evolving and producing oxygen
Phase 2 - What happened to the carbondioxide atmosphere?
It dissolved into oceans. Green plants and algae also absorbed some and produced oxygen through photosynthesis.
Phase 2 - what happened to the plants, algae, skeletons and shells of marine organisms?
The plants and algae died and were burried under layers of sediment along with skeletons and shells of marine organisms that had slowly evolved. The carbons and hydrocarbons inside them became locked up in sedimentary rocks and insoluble carbonates and fossil fuels.
What happened in phase 3 in the evolution if the atmosphere?
The ozone layer allows the evolution of complex animals
Phase 3 - what did the build up of oxygen in the atmosphere do?
It killed off some early organisms that couldn’t tolerate it which allowed other more complex organisms to evolve and flourish
Phase 3 - what did the oxygen create?
The ozone layer which blocked harmful rays from the sun and enabled even more complex organisms to evolve
