EESA06H3 Lecture 6: Lecture 6
Document Summary
Then planets differentiated: once earth got haidian, then we got magnetic field. The way we know about how life used to exist before that we don"t know about is through fossils: mt vasuvis has pyroclastic flow. Fossil and rock other than sedimentary in only this case: cavities within shell or creature are filled in with minerals. Called mineralization: minerals can come out and grow or precipitate in shell, stumps are fossilized. Minerals come in and precipitated out and preserved them. People buy big stumps to use as tables or as decoration: process called permineralization. Creature dies near or in water and decomposes with bacteria. Then you get sedimentation (sediments that pile on top of dead critter on top): fine grained like clay or silt, then you get defined material. Wind, rain works to wear away rocks: erosion would make entire planet flat and ocean if there were no.
