Book F Chapter 3 Time

Front 1

uniformitarianism

Back 1

A principle that states the gelogic processes that occured in the past can be explained by current gelogic processes

Front 2

uniformitarianism

Back 2

a principle that states that geologic processes that occuredin the past can be explaines by current geologic processes

Front 3

catastrophism

Back 3

a principle that states that geologic change occurs suddenly

Front 4

palentology

Back 4

the scientific study of fossils

Front 5

relative dating

Back 5

any method determining wheather an event or object is older or younger than other events or objects

Front 6

superposition

Back 6

a principle that states that younger rocks live above older rocks if the lays
ers have not been disturbed

Front 7

geologic column

Back 7

an arrangement of rock layers in which the oldest rocks are at the bottom.

Front 8

unconformity

Back 8

a break in the geologic record created when rock layers are eroed or when sediment is not deposites for a long period of time

Front 9

index fossil

Back 9

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.

Front 10

absoulute dating

Back 10

any method of measuring the age of an event or object in years

Front 11

isotope

Back 11

a atom that has the same numberof protons (or the same atomic number)as other atoms of the same element do but that has a different number of newtrons ( and thus a different atomic mass

Front 12

Uniformitarianism

Back 12

A principle that states that geologic process that occured in the past can be explained by current geolgic process.C

Front 13

Catastrophism

Back 13

A principle that states that geologic change occurs suddenly.

Front 14

Paleontology

Back 14

The scientific study of fossils.

Front 15

Relative Dating

Back 15

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

Front 16

Superposition

Back 16

A princible that states that a younger rock lie about older rocks if the layers have not been disturbed.

Front 17

Geologic Column

Back 17

An arrangement of rock layers in which the oldest rocks are at the bottom.

Front 18

Unconformity

Back 18

A break in the geologic record created when rock layers are eroded or when sediment is not deposited for a long time.

Front 19

Index Fossil

Back 19

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.

Front 20

Absolute Dating

Back 20

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

Front 21

Isotope

Back 21

An atom that has the same number of protons (or the same atomic number) as other atoms of the same elent do but that has a different number of neutrons (and the a different atomic mass)

Front 22

radioactive decay

Back 22

the process in which a radioactive isotope tends to break down into a stable isotope of the same element or another element

Front 23

radiometric dating

Back 23

a method of determining age of an object by estimating the realive percentages of a radioactive (parent) isotope and a stable (daughter) isotope

Front 24

half-life

Back 24

the time needed for half of a sample of radioactive substance to undergo radioactive decay.

Front 25

fossil

Back 25

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

Front 26

trace fossil

Back 26

a fossilized mark that is formed in soft sediment by the movement by the movement of an animal.

Front 27

mold

Back 27

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

Front 28

cast

Back 28

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

Front 29

geologic time scale

Back 29

the standard method used to divide the earths long natural history into managabele parts.

Front 30

eon

Back 30

the largest division of geologic time

Front 31

era

Back 31

a unit of geologic time that includes two or more periods.

Front 32

period

Back 32

a unit of geologic time that includes two or more periods.

Front 33

epoch

Back 33

a unit of geologic time into which eras are divided

Front 34

extinction

Back 34

a subsavision of a geologic period.

Front 35

Radioactive Decay

Back 35

The process in which a radioactive isotope tends to break down into a stable isotope of the same element or another element.

Front 36

Radiometric Dating

Back 36

A method of determining the age of an object by estimating the relative percentages of a radioactive (parent) isotope and as table (daughter)isotope.

Front 37

Half-Life

Back 37

The time needed for half of a sample of a radioactive substance to undergo radioactive decay.

Front 38

Fossil

Back 38

The remains or physical evidence of an organism preserved by geological processes.

Front 39

Trace Fossil

Back 39

A fossilized mark that is formed in soft sediment by the movement of an animal.

Front 40

Mold

Back 40

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

Front 41

Cast

Back 41

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

Front 42

Geologic Time Scale

Back 42

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

Front 43

Eon

Back 43

The largest division of geologic time.

Front 44

Era

Back 44

A unit of geologic time that includes two or more periods.