Planet Earth 12 - Chapter 12 Geologic Time: the span of...

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Chapter 12 Geologic Time: the span of time since Earth’s formation -geologic time exceeded historical time Princtple of uniformitarianism: the resent is the key to the past Relative Age: the age of one geologic feature with respect to another Numerical age: the age of a feature given in years Defining relative age: -Principle of uniformitarianism -Principle of superposition -Principle of original horizontality -Principle of original continuity -Principle of cross-cutting relations -Principle of inclusions -Principle of bake/chilled contacts Geologic history: the sequence of geologic events that has taken place in a region Fossil assemblage: a group of fossil species found in a specific sequence of sedimentary rock Principle of fossil succession: in a stratigraphic sequence, different species of fossil organisms appear in a definite order; once a fossil species disappears in a sequence of strata, it never reappears higher in the sequence -Due to principle of fossil succession, we can define the relative ages of strata by looking
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Planet Earth 12 - Chapter 12 Geologic Time: the span of...

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