History of the Earth

Question 1

_______ deals with the study of any layered (stratified) rock

Answer 1

Stratigraphy

Question 2

Stratigraphy deals with the study of any layered (stratified) rock, but primarily with sedimentary rocks and their

Answer 2

composition, origin, age relationships, geographic extent

Question 3

Many igneous rocks such as a ______ of lava flows, or ash beds

Answer 3

succession

Question 4

Many igneous rocks such as a succession of lava flows, or ash beds are _____ and obey the principles of stratigraphy

Answer 4

stratified

Question 5

Many metamorphic rocks are _______

Answer 5

stratified

Question 6

Used to determine whether an object or event is older or younger than other objects or events

Answer 6

relative dating

Question 7

What type of rock is used in relative dating?

Answer 7

sedimentary rocks

Question 8

Sedimentary rocks are used in relative dating because:

Answer 8

• Formed from fragments of other type of rocks
• New rock layers are almost always flat
• Fossils are deposited in these layer of rocks

Question 9

To deduce the geological history of the Earth, there are ideas or laws that need to be considered

Answer 9

law of original horizontality, law of superposition, principle of cross-cutting relations, unconformities

Question 10

Principle of Original _____ states that layers of sediments deposited horizontally under action of gravity.

Answer 10

horizontality

Question 11

(super = _____; positum = _____)

Answer 11

above; to place

Question 12

simply states that in an undeformed sequence of sedimentary rocks, each bed is older than the one above and younger than the one below.

Answer 12

law of superposition

Question 13

Layering of rocks from oldest to youngest described by principle of _________.

Answer 13

superposition

Question 14

The principle of _________ states that geologic features that cut across rocks must form after the rocks they cut through.

Answer 14

cross-cutting relations

Question 15

The ____ is a tabular mass of igneous rock that cuts through the surrounding rocks

Answer 15

dike

Question 16

The dike is a tabular mass of igneous rock that cuts through the surrounding rocks. The magmatic heat from igneous intrusions often creates a narrow “_____” zone of contact metamorphism on the adjacent rock, also indicating that the intrusion occurred after the surrounding rocks were in place.

Answer 16

baked

Question 17

an igneous intrusion is younger than the rocks that are included

Answer 17

Cross-cutting dike

Question 18

It shows a mass of rock that is offset by a fault, a fracture in rock along which displacement occurs. It is clear that the rocks must be ____ than the fault that broke them.

Answer 18

older

Question 19

the rocks are older than the fault that displaced them

Answer 19

cross-cutting fault

Question 20

Throughout Earth history, the deposition of sediment has been interrupted over and over again. All such breaks in the rock record are termed ______.

Answer 20

unconformities

Question 21

An _______ represents a long period during which deposition ceased, erosion removed previously formed rocks, and then deposition resumed.

Answer 21

unconformity

Question 22

There are three basic types of unconformities: __________________________________

Answer 22

angular unconformities, disconformities, and nonconformities.

Question 23

the layers on either side of this gap in the rock record are essentially parallel

Answer 23

disconformity

Question 24

younger sedimentary rocks rest atop older metamorphic or igneous rock

Answer 24

nonconformity

Question 25

An _____ unconformity represents an extended period during which deformation and erosion occurred.

Answer 25

angular

Question 26

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

Answer 26

absolute dating

Question 27

Determining the actual age of an event or object in years.

Answer 27

absolute dating

Question 28

To determine the absolute ages of fossils and rocks, scientists analyze ______ of radioactive elements.

Answer 28

isotopes

Question 29

By adding together the number of protons and neutrons in the nucleus, the mass number of the atom is determined. The number of neutrons in the nucleus can vary. These variants, called _____, have different mass numbers.

Answer 29

isotopes

Question 30

:forms of elements with different atomic mass.

Answer 30

Isotopes

Question 31

For a given element the atomic number remains the ______, therefore the _____ of neutrons is different.

Answer 31

same; number

Question 32

The forces that bind protons and neutrons together in the nucleus are usually ____.

Answer 32

strong

Question 33

As a result, the nuclei spontaneously break apart (decay) in a process called ______.

Answer 33

radioactivity

Question 34

_________: isotopes of elements that change spontaneously by losing or gaining subatomic particles.

Answer 34

Radioactive isotopes

Question 35

For many isotopes the change from ____ element to stable _____ product does so through many steps.

Answer 35

parent; daughter

Question 36

The path from parent element to stable daughter produce is termed the _______ for the parent.

Answer 36

Radioactive Series

Question 37

Radioactive decay takes place at a ____ rate and has done so over all of geologic time

Answer 37

constant

Question 38

Parent is ____ in amount. Daughter product ____ iin amount. At a ___ rate

Answer 38

reduced increase constant

Question 39

Half-life of an isotope: the time taken for the amount of parent to be reduced by ___

Answer 39

½

Question 40

Over successive half lives the parent is constantly ___ in amount and the daughter ____ in amount.

Answer 40

reduced; increases

Question 41

Certainly among the most important properties of radioactivity is that it provides a reliable method of calculating the ages of rocks and minerals that contain particular radioactive isotopes. The procedure is called _________

Answer 41

radiometric(radioactive) dating.

Question 42

The time required for one-half of the nuclei in a sample to decay is called the ___ of the isotope

Answer 42

half-life

Question 43

_____ is a common way of expressing the rate of radioactive disintegration.

Answer 43

Half-life

Question 44

In _________, an unstable radioactive isotope of one element breaks down into a stable isotope.

Answer 44

radioactive decay

Question 45

,______ radioactive isotope is the parent isotope.

Answer 45

Unstable

Question 46

Stable radioactive isotope produced by the radioactive decay of the parent isotope is called the ________.

Answer 46

daughter isotope

Question 47

To date very recent events, ______ i used

Answer 47

carbon-14

Question 48

Carbon-14 is the ________ of carbon. The process is often called ,_________.

Answer 48

radioactive isotope; radiocarbon dating

Question 49

Because the half-life of carbon-14 is only ___ years, it can be used for dating events from the historic past as well as those from very recent geologic history.

Answer 49

5730

Question 50

In some cases, ____ can be used to date events as far back as _______

Answer 50

carbon-14; 70,000 years.

Question 51

It is the remnant of any ancient animal or plant that has been preserved in rocks.

Answer 51

fossil

Question 52

It is often the remains of the shell or bones in which minerals have crystallized.

Answer 52

fossil

Question 53

The age of the fossil is ____ to the age of the rock on which it is found

Answer 53

equal

Question 54

_____ provide clues to the prehistoric Earth and the organisms that existed.

Answer 54

Fossils

Question 55

However, all fossils cannot be used as ______ fossil.

Answer 55

index

Question 56

An index fossil must have the following properties:

Answer 56

• It must have had hard parts, like a shell. • It must have lived over a short period on time, before it evolved into different creature. • It must have lived all over the planet

Question 57

types of fossil

Answer 57

Permineralization, Molds and Casts, Carbonization, Impression, Amber, Trace Fossils, Tracks, Burrows, Gastroliths

Question 58

When mineral-rich groundwater permeates porous tissue such as bone or wood, minerals precipitate out of solution and fill pores and empty spaces

Answer 58

permineralization

Question 59

The wood is gradually transformed into chert, sometimes with colorful bands from impurities such as iron or carbon.

Answer 59

permineralization

Question 60

The word petrified literally means “turned into stone.”

Answer 60

permineralization

Question 61

The word petrified literally means “_________.”

Answer 61

turned into stone

Question 62

When a shell or another structure is buried in sediment and then dissolved by underground water, a mold is created. The mold faithfully reflects only the shape and surface marking of the organism; it does not reveal any information concerning its internal structure.

Answer 62

molds and casts

Question 63

If these hollow spaces are subsequently filled with mineral matter, _____ are created.

Answer 63

casts

Question 64

type of fossilization called _______ is particularly effective in preserving leaves and delicate animal forms.

Answer 64

carbonization

Question 65

It occurs when fine sediment encases the remains of an organism. As time passes, pressure squeezes out the liquid and gaseous components and leaves behind a thin residue of carbon.

Answer 65

carbonization

Question 66

f the film of carbon is lost from a fossil preserved in finegrained sediment, a replica of the surface, called an _______, may still show considerable detail.

Answer 66

impression

Question 67

Delicate organisms, such as insects, are difficult to preserve, and consequently they are relatively rare in the ____________.

Answer 67

fossil record

Question 68

Delicate organisms, such as insects, are difficult to preserve, and consequently they are relatively rare in the fossil record.

Answer 68

amber

Question 69

Not only must they be protected from decay but they must not be subjected to any pressure that would crush them. One way in which some insects have been preserved is in ________, the hardened resin of ancient trees.

Answer 69

amber

Question 70

different kinds of trace fossils

Answer 70

coprolites, tracks, burrows, gastroliths

Question 71

animal footprints made in soft sediment that later turned into sedimentary rock

Answer 71

tracks

Question 72

fossil dung and stomach contents that can provide useful Information pertaining to the size and food habits of organisms.

Answer 72

coprolites

Question 73

ubes in sediment, wood, or rock made by an animal. These holes may later become filled with mineral matter and preserved. Some of the oldest-known fossils are believed to be worm _____.

Answer 73

burrows

Question 74

highly polished stomach stones that were used in the grinding of food by some extinct reptiles.

Answer 74

gastroliths