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Proterozoic. Snowball Earth Theory. Snowball earth theory. From 750-600 Million years, lots of glaciers Sea ice 0.5 mile thick, temp ~ -40° everywhere Most organisms die. How to warm up to form limestone?. No photosynthesis Build up of CO 2 Switch to hothouse
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Proterozoic Snowball Earth Theory
Snowball earth theory • From 750-600 Million years, lots of glaciers • Sea ice 0.5 mile thick, temp ~ -40° everywhere • Most organisms die
How to warm up to form limestone? • No photosynthesis • Build up of CO2 • Switch to hothouse • Ready for explosion of life after Proterozoic
Snowball Earth Theory • Global glacial deposits younger than 600 Ma • On top, limestone
Snowball Earth Theory • Limestone only forms in warm water • Limestone dissolves in cold water