Chapter 4

Question 1

study of rock units’ three-dimensional distribution and deformation history.

Answer 1

structural geology

Question 2

It specializes with understanding how rocks respond to tectonic forces, as well as the processes that cause formation to geologic structures like folds, faults, and joints.

Answer 2

structural geology

Question 3

its objective is to understand the history of deformation in the Earth’s crust and predict the mechanical behavior of rocks under various stress conditions. Intense geologic activities occur at plate boundaries where plates move away from one another, past one another, or toward one another.

Answer 3

structural geology

Question 4

is the idea that continents move freely over the earth’s surface, changing their positions relative to one another.

Answer 4

continental drift

Question 5

he noted that geographic fit of continents e.g. Africa and South America, Atlantic formed by separation of Africa from South America, and speculates that earthquakes and flooding may have the separation possible.

Answer 5

Abraham Ortelius

Question 6

he proposed supercontinent by studying fossils, rocks, mountains.

Answer 6

Seuss

Question 7

proposed continental drift and Pangaea, and claimed that there used to be only one supergiant landmass where all continents came from.

Answer 7

Wegener and Taylor

Question 8

suggested the idea of thermal convection as the driving force for the movement of continents.

Answer 8

Arthurs Holmes

Question 9

• Continents seem to fit together like pieces of a puzzle

Answer 9

Geographic Fit

Question 10

Supporting Evidences of Continental Drift:

Answer 10

Fossils
Coal Seams
Mountains
Glacial Deposits

Question 11

Similar distribution of ___________ such as Mesosaurus have been found in different regions and continents.

Answer 11

Fossils

Question 12

Usually, coal is found in tropical areas because the climate is warm and ideal for the propagation of organisms. Coal would be found in polar regions such as North Pole and Antarctica.

Answer 12

coal seams

Question 13

Usually, _____________is found in tropical areas because the climate is warm and ideal for the propagation of organisms. ___________would be found in polar regions such as North Pole and Antarctica.

Answer 13

coal
coal

Question 14

Mountain ranges match across oceans (similar rock layers & rock types).

Answer 14

mountains

Question 15

Places that are presently known to tropical and desert like such as Africa, Madagascar and India finding ice deposits would seem unreasonable if not for the concepts of drifting continents.

Answer 15

glacial deposits

Question 16

is a hypothesis that the sea floors form at the crest of the mid-oceanic ridge, then move horizontally away from the ridge crest toward an oceanic trench.

Answer 16

Sea-floor Spreading

Question 17

is a continuous process where tensional forces on both sides of plate cause them to constantly move apart.

Answer 17

Sea-floor Spreading

Question 18

Sea-floor spreading suggests that the seafloor moves away from the mid-oceanic ridge as a result of _____________.

Answer 18

mantle convection

Question 19

who developed sea-floor spreading

Answer 19

Harold Hess and Robert Dietz

Question 20

is the sliding of the seafloor beneath a continent or island arc.

Answer 20

Subduction

Question 21

Hess hypothesis was that seafloor spreading is driven by ___________________.

Answer 21

deep mantle convection.

Question 22

is a circulation pattern driven by the rising of hot material and/or sinking of cold material.

Answer 22

Convection

Question 23

In seafloor spreading, ____________ rises to the surface from the mantle. In time magma is cooled by seawater and forms the ____________ crust. New________________ created at the mid-ocean ridge and destroyed in deep ocean trenches.

Answer 23

magma
oceanic
sea floor

Question 24

Supporting Evidence for Seafloor Spreading

Answer 24

World Seismicity
Volcanism
Age of Sea floor
Paleomagnetism
Heat flow

Question 25

Earthquake distribution matches plate boundaries.

Answer 25

World Seismicity

Question 26

Volcanoes match some plate boundaries; some are hot spots.

Answer 26

Volcanism

Question 27

___________ Seafloor is at mid-ocean ridge; ________ sea floor away from mid-ocean ridge.

Answer 27

Youngest oldest

Question 28

___________ sea floor is continually being formed by basalt eruptions at the ridge crest. This basalt is then carried sideways by convection and is subducted in to the mantle at an oceanic trench.

Answer 28

New, young sea floor is continually being formed by basalt eruptions at the ridge crest. This basalt is then carried sideways by convection and is subducted in to the mantle at an oceanic trench.

Question 29

___________ seafloor is continually being destroyed at trenches, while ________ sea floor is being formed at the ridge crest.

Answer 29

old new

Question 30

old seafloor is continually being destroyed at _________ , while new sea floor is being formed at the ____________.

Answer 30

trenches ridge crest

Question 31

Because the ocean floor is mostly composed of basalt, an iron-rich substance containing minerals that align with the magnetic field, they record the alignment of the magnetic fields surrounding oceanic ridges.

Answer 31

paleomagnetism

Question 32

Studies conducted with thermal probes, for example, indicate that the heat flow through bottom sediments is generally comparable to that through the continents except over the mid-ocean ridges, where at some sites the heat flow measures three to four times the normal value. The anomalously high values are considered to reflect the intrusion of molten material near the crests of the ridges.

Answer 32

Heat Flow

Question 33

________________ combined ideas of continental drift and seafloor spreading into "Plate Tectonics".

Answer 33

John Tuzo Wilson

Question 34

It is the combined ideas of continental drift and seafloor spreading into

Answer 34

Plate Tectonics

Question 35

is a large mobile slab of rock that is part of the Earth's surface.

Answer 35

Plate

Question 36

Its interior is inactive tectonically.

Answer 36

Plate

Question 37

Plates interact with each other along their edges (_____________________) that has a high degree of tectonic activities which causes the geologic processes such as earthquakes, etc. Earth's outermost layer composed of thin rigid plates moving horizontally.

Answer 37

(plate boundaries

Question 38

is the rising of Earth's crust to higher elevations.

Answer 38

Uplift

Question 39

is the sinking of regions of Earth's crust to lower elevations.

Answer 39

subsidence

Question 40

Rocks that are uplifted _____ or ___________ be highly deformed.

Answer 40

may or may not

Question 41

Rocks that subside ________ undergo deformation.

Answer 41

do not

Question 42

There are three types of plate boundaries based on the movement.

Answer 42

Divergent Plate Boundary Convergent Plate Boundary Transform Plate Boundary

Question 43

is boundary between plates that are moving apart, creating new crust.

Answer 43

Divergent Plate Boundary

Question 44

These boundaries are typically found along mid-ocean ridges, where seafloor spreading occurs. As the plates separate, magma rises from below to fill the gap, creating new oceanic crust.

Answer 44

Divergent Plate Boundary

Question 45

lies between plates that are moving toward each other.

Answer 45

Convergent Plate Boundary

Question 46

At these boundaries, plates collide.

Answer 46

Convergent Plate Boundary

Question 47

When two plates of different densities meet (for example, an oceanic and a continental plate), the denser plate is forced beneath the lighter one in a process called ______________.

Answer 47

subduction

Question 48

This leads to the formation of deep ocean trenches and volcanic mountain chains.

Answer 48

Convergent Plate Boundary

Question 49

In the case of two continental plates colliding, ________________s like the Himalayas are formed.

Answer 49

massive mountain range

Question 50

is where one plate dives or subducts under the other.

Answer 50

ocean to ocean convergence

Question 51

is where the dense oceanic plates under the continental plate. Forms an active continental margin between the trench and the continent.

Answer 51

ocean to continent convergence

Question 52

is where the plates collide and crumble but neither is subducted.

Answer 52

continent to continent convergence

Question 53

is at which two plates move horizontally or laterally past each other.

Answer 53

transform plate boundary

Question 54

In transform plate boundary, __________ is neither created nor destroyed.

Answer 54

Crust

Question 55

Most common type of transform fault occurs on fracture zones and connects two divergent plate boundaries. These boundaries are characterized by ___________ faults and can generate significant earthquakes, as seen along the San Andreas Fault in California.

Answer 55

strike-slip

Question 56

These are forces that tends to move or change the orientation of the plate (along earth's crust)

Answer 56

tectonic forces

Question 57

Deep within the Earth's crust, rocks are constantly being squeezed, stretched, and sheared. This process is known as ______________, and it is driven by forces that cause rocks to bend, break, or flow.

Answer 57

rock deformation

Question 58

When studying rock deformation, geologist typically refer to ___________ , a force per unit area or the force applied to a material, divided by the area over which it is applied.

Answer 58

stress

Question 59

stress produces ___________ which is when there's a change in size (volume), shape, or both while an object is undergoing stress.

Answer 59

strain

Question 60

3 kinds of stress

Answer 60

tensional stress compressive stress shear stress

Question 61

caused by forces pulling away from one another from opposite directions. It causes stretching or extensional strain.

Answer 61

tensional stress

Question 62

It is common at divergent boundaries, where tectonic plates are moving away from each other.

Answer 62

tensional stress

Question 63

causes rocks to become thinner and can lead to the formation of normal faults.

Answer 63

tensional stress

Question 64

caused by forces pushing or squeezing towards one another in an opposite direction.

Answer 64

compressive stress

Question 65

It causes shortening strain.

Answer 65

compressive stress

Question 66

It occurs at convergent boundaries, where plates collide

Answer 66

compressive

Question 67

results in the thickening of the crust and the formation of mountains, as well as the development of reverse faults.

Answer 67

compressive

Question 68

due to movement parallel to but in opposite directions along a fault or other boundary.

Answer 68

shear stress

Question 69

It causes shear strain. It is most commonly found at transform boundaries, where plates move laterally.

Answer 69

shear stress

Question 70

This type of stress can result in strike-slip faults.

Answer 70

shear stress

Question 71

Behaviors of Rocks to Stress and Strain

Answer 71

elastic ductile brittle

Question 72

is if the deformed body recovers its original shape after the stress is reduced or removed.

Answer 72

elastic

Question 73

is the maximum stress or force per unit area within a solid material that can arise before the onset of permanent deformation.

Answer 73

elastic limit

Question 74

is if it bends while under stress and does not return to its original shape after relaxation of the stress

Answer 74

ductile

Question 75

Are folds elastic, ductile, or brittle?

Answer 75

ductile

Question 76

This type of deformation occurs at higher temperatures and pressures, deep within the Earth.

Answer 76

ductile

Question 77

is if it breaks or creates a fracture at stresses higher than its elastic limit

Answer 77

brittle

Question 78

Are faults elastic, ductile, or brittle?

Answer 78

brittle

Question 79

Are joints elastic, ductile, or brittle?

Answer 79

brittle

Question 80

This type of deformation is typical of rocks in the upper crust, where temperatures are lower and rocks are more rigid.

Answer 80

brittle

Question 81

are natural breaks or cracks in rocks, often occurring due to tectonic stresses or rock deformation

Answer 81

fractures

Question 82

are fractures without significant displacement.

Answer 82

joints

Question 83

formed when tension and compression associated with plate movement is so great that blocks of rock fracture or break apart

Answer 83

faults

Question 84

______________ of a non-horizontal bed, is the compass orientation of a line formed by the intersection of an imaginary horizontal plane with the inclined bedding plane.

Answer 84

strike

Question 85

___________________of the inclined rock layer is the angle between the imaginary horizontal plane and the inclined rock layer.

Answer 85

Dip

Question 86

It is formed from movement of rock along the dip of the fault plane.

Answer 86

Dip-slip Faults:

Question 87

3 types of dip=slip faults

Answer 87

normal fault reverse fault thrust fault

Question 88

forms when the hanging-wall rock moves downward compared to the footwall. This occurs when rocks move away from each other due to the land moving apart.

Answer 88

normal fault

Question 89

is formed if the hanging wall moves up along a dip-slip fault compared to the footwall and if the fault dips at an angle steeper than 45 degrees.

Answer 89

reverse fault

Question 90

is formed if the fault dips at an angle less than 45 degrees.

Answer 90

thrust fault

Question 91

It is formed by horizontal movement along the strike direction of the fault plane.

Answer 91

strike-slip fault

Question 92

forms if features appear shifted to the left from one side of the fault to the other.

Answer 92

Left-lateral Strike-slip Fault

Question 93

forms if features shift to the right across the fault.

Answer 93

Right-lateral Strike-slip Fault

Question 94

It is a combination of dip-slip and strike-slip movements in which diagonal motion occurs along the fault plane, both along the strike and dip.

Answer 94

Oblique-slip Faults:

Question 95

is formed when two normal faults occur parallel to each other and the land sinks between the faults.

Answer 95

Rift Valley or Graben

Question 96

is the opposite of a rift valley where the land between the parallel faults is forced upward because the two faults are being pushed together.

Answer 96

Horst

Question 97

Graben or Horst? Compressive and forced upward

Answer 97

Horst

Question 98

Graben or Horst? Tensional and sinks in

Answer 98

Graben

Question 99

are bends or wave like features in layered rock. It occurs with convergent or compression motion.

Answer 99

folds

Question 100

. It is usually strained in a ductile way than elastic or brittle strain.

Answer 100

folds

Question 101

are arched folds where limbs dip away from the hinge line.

Answer 101

ANTICLINES

Question 102

Oldest rocks are exposed along the hinge line.

Answer 102

anticlines

Question 103

are trough-shaped folds where limbs dip toward the hinge line.

Answer 103

syncline

Question 104

Younger rocks are exposed along the hinge line.

Answer 104

syncline

Question 105

is a type of fold in which limbs are parallel to each other, implies intense compressive stress.

Answer 105

isoclinal folds

Question 106

is a type of fold in which upper limb of the fold override the lower limb that implies unequal compressive and/or shear stress.

Answer 106

overturned fold

Question 107

is a type of fold that are overturned to such an extent that the limbs are essentially horizontal and indicates compressive and/or shearing stress is more intense in one direction.

Answer 107

recumbent folds