Chapter 5 Vocabulary Flashcards Preview

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Flashcards in Chapter 5 Vocabulary Deck (19)
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1

Uniformitarianism

A principle that geologic processes that occurred in the past can be explained by current geologic processes.

2

Catastrophism

A principle that states that geologic change occurs suddenly.

3

Relative Age

The approximate age of fossils or other objects in rock layers determined by comparing whether the surrounding rock layers are younger or older.

4

Relative Dating

Any method of determining whether an event or object is older or younger than other events or objects.

5

Geologic Column

An ordered arrangement of rock layers that is based on the relative ages of the rocks and in which the oldest rocks are at the bottom.

6

Absolute Dating

Any method of measuring the age of an event or object in years.

7

Paleontology

The scientific study of fossils.

8

Fossil

The trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock.

9

Trace Fossil

A fossilized mark that formed in sedimentary rock by the movement of an animal on or within soft sediment.

10

Mold

A mark or cavity made in a sedimentary surface by a shell or other body

11

Cast

A type of fossil that forms when sediments fill in the cavity left by a decomposed organism.

12

Index Fossil

A fossil that is used to establish the age of a rock layer because the fossil is distinct, abundant, and widespread and the species that formed that fossil existed for only a short span of geologic time.

13

Geologic Time Scale

The standard method used to divide Earth's long natural history into manageable parts.

14

Eon

The largest division of geologic time; divided into eras.

15

Era

A unit of geologic time that includes two or more periods

16

Period

A unit of geologic time that is longer than an epoch but shorter than an era

17

Epoch

A subdivision of geologic time that is longer than an age but shorter than a period.

18

Extinction

The death of every member of a species.

19

From largest to smallest, name the geological time divisions

Eon, era, period, epoch