Term
| relative dating = ___ ___. |
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Definition
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Term
| absolute dating = ___ ___. |
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Definition
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Term
| Determine order in which formations deposited? |
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Definition
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Term
determine the actual age of a rock
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radiometric dating? |
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Definition
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Term
| In an undeformed sequence of sedimentary rocks (or layered igneous rocks), the oldest rocks are on the bottom.? |
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Definition
| Principle of superposition |
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Term
Layers of sediment are generally deposited in a horizontal position.
•
If rocks are folded or faulted, that happened after deposition? |
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Definition
| Principle of original horizontality |
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Term
a piece of rock that is enclosed within another rock
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Rock containing the inclusion is younger? |
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Definition
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Term
| a break in the rock record produced by erosion and/or nondeposition of rock units? |
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Definition
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Term
| Types of unconformities are __ ,___, ___ ___. |
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Definition
| disconformity; nonconformity; angular uncomformity |
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Term
| strata on either side of the unconformity are parallel |
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Definition
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Term
| younger sedimentary rocks lie on older igneous or metamorphic rocks? |
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Definition
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Term
| tilted or folded rocks are overlain by flat-lying rocks? |
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Definition
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Term
Younger features cut across older feature
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If a fault cuts rocks or magma intrudes rock? |
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Definition
| Principle of cross-cutting relationships |
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Term
| Fossils are generally found in ____ rock. |
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Definition
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Term
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Definition
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Term
| Fossils: Evidence of past life? |
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Definition
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Term
| Matching of rocks of similar ages in different regions? |
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Definition
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Term
fossil organisms succeed one another in a definite and determinable order, and
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Rock layers of different ages contain different fossils so any time period can be recognized by its fossil content? |
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Definition
| principle of fossil succesion |
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Term
geographically widespread fossil that is limited to a short span of geologic time
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useful to correlate rocks of the same age from one area to another? |
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Definition
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Term
| rocks in different locations can be the ___ ___. |
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Definition
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Term
| the same units in the same order? |
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Definition
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Term
| fossils succeed one another in a definite and determinable order? |
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Definition
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Term
| Use naturally occurring radioactive elements to determine the absolute ages of rocks? |
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Definition
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Term
| an unstable nucleus that spontaneously disintegrates to form a different element or different isotope of the same element? |
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Definition
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Term
| Radioactive element is __ __. |
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Definition
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Term
lose 2 protons and 2 neutrons
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atomic number is 2 less
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atomic mass is 4 less? |
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Definition
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Term
turn a neutron into a proton
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atomic number is 1 more
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atomic mass does not change? |
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Definition
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Term
turn a proton into a neutron
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atomic number is 1 less
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atomic mass does not change? |
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Definition
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Term
| the original unstable radioactive isotope of the element? |
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Definition
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Term
| the new isotope formed upon decay of the parent? |
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Definition
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Term
| at end of decay path is a ___ ___. |
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Definition
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Term
| Time required for half of the mass of the unstable parent isotope in a sample to decay to the daughter isotope? |
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Definition
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Term
| Use elements with longer half lives to date ___ rocks and elements with shorter half lives to date____rocks. |
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Definition
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Term
| Rock that has long half life? |
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Definition
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Term
| rock that has short half life? |
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Definition
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Term
| we can date ___ and ___ rocks. |
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Definition
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Term
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Definition
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Term
era where large vertebrates and dinosaurs existed
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The extinction of the dinosaur marks the end of this era? |
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Definition
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Term
| era with abundant shells and small vertebrates? |
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Definition
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