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Big Bang Theory
the earliest event in widely held scientific model of the origin of the known
the collection of preserved organisms or their traces stored in the lithosphere providing an image of past life and conditions on Earth
principle of superposition
concept that in an undisturbed rock sequence, more recent rock layers are deposited on top of older rock layers
the estimation of age of an object by comparison of the ratios of appropriate isotopes with known rates of decay
the use of cross-comparisons of rock layers to establish older and younger geologic layers
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