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16 Cards in this Set
- Front
- Back
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Absolute Age |
The actual number of years elapsed from a geologic event until now
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Eon |
The largest division of geologic time, including multiple eras |
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Epoch |
A division of geologic time representing one subdivision of a period |
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Era |
A division of geologic time representing one subdivision of an eon and including multiple periods |
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Geologic Time Scale |
A worldwide history of geologic events that divides Earths history into intervals, many of which are marked by distinctive sets of fossils and bounded by times when those sets of fossils changed abruptly |
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Half-Life |
The time required for one-half the original number of parent atoms in a radioactive isotope to decay |
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Isotopic Dating |
The use of naturally occurring radioactive elements to determine the ages of rocks |
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Mass Extinction |
A short interval during which a large proportion of the species living t the time disappear from the geologic record |
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Period |
A division of geologic time representing one subdivision of an era |
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Principle of Faunal Succession |
A stratigraphic principle stating that the sedimentary rock strata in an outcrop contain distinct fossils in a definite sequence |
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Principle of Original Horizontally |
A stratigraphic principle stating that sediments are deposited as essential horizontal beds |
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Principle of Superposition |
A stratigraphic principle that each sedimentary rock stratum in a tectonically undisturbed sequence is younger than the one beneath it and older than the one above it |
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Relative Age |
The age of one geologic event in relation to another |
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Statigraphic Succession |
A chronologically ordered set of rock strata |
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Stratigraphy |
The description, correlation, and classification, of strata in sedimentary rocks |
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Unconformity |
A surface between two rock layers in a stratigraphic succession that were laid down with a time gap between them |
