Term
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Definition
| a principle that states that geologic processes that occurred in the past can be explained by current geologic processes |
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Definition
| a principle that states that geologic change occurs suddenly |
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Term
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Definition
| the scientific study of fossils |
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Term
| give one example of catastrophic global change |
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Definition
| a global climate change caused by an asteroid striking Earth |
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Term
| describe the work of 3 types of paleontologists |
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Definition
vertibrate paleontologists-study fossils of animals that have backbones
invertibrate paleontologists-study fossils of animals that do not have backbones
paleobotanists study plant fossils |
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Term
| which came first---uniformitarianism or catastrophism |
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Definition
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Definition
| any method of determining whether an event or object is older or younger than other events or objects |
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Definition
| a principle that states that younger rocks lie above older rocks if the layers have not been disturbed |
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Term
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Definition
| an arrangement of rock layers in which the oldest rocks are at the bottom |
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Definition
| a break in the geologic record created when rock layers are eroded or when sediment is not deposited for a long period of time |
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Term
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Definition
| exists where part of a sequence of parallel rock layers is missing |
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Definition
| exists where sedimentary rock layers lie on top of an eroded surface of nonlayered igneous or metamorphic rock |
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Term
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Definition
| exists between horizontal rock layers and rock layers that are tilted or folded |
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Term
| list 2 events and 2 features that can disturb rock-layer sequences |
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Definition
events-folding and tilting
features-faults and intrusions |
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Term
| how are physical features used to determine relative ages |
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Definition
| the way physical features form determines the order in which events occurred thereby determining relative ages |
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Term
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Definition
| any method of measuring the age of an event or object in years |
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Term
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Definition
| an atom that has the same number of protons as other atoms of the same element do but that has a different number of neutrons |
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Definition
| the process in which a radioactive isotope tends to break down into a stable isotope of the same element or another element |
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Term
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Definition
| a method of determining the age of an object by estimating the relative percentages of a radioactive (parent) isotope and a stable (daughter) isotope |
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Term
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Definition
| the time needed for half of a sample of a radioactive substance to undergo radioactive decay |
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Term
| list four types of radiometric dating |
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Definition
potassium-argon
uranium-lead
strontium-rubidium
carbon-14 |
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Term
| Rubidium-87 has a half-life of? |
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Definition
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Term
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Definition
| the trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock |
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Term
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Definition
| a fossilized mark that is formed in soft sediment by the movement of an animal |
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Definition
| a mark or cavity made in a sedimentary surface by a shell or other body |
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Term
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Definition
| a type of fossil that forms when sediments fill in the cavity left by a decomposed organism |
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Term
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Definition
| a fossil that is found in the rock layers of only one geologic age and that is used to establish the age of the rock layers |
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Term
| fossils are most often preserved in? |
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Definition
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Term
| describe 3 types of trace fossils |
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Definition
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Term
| why is the fossil record an incomplete record of the history of life on Earth? |
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Definition
| because most organisms, such as organisms that have soft body parts, did not become fossils, and many fossils have yet to be discovered |
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