Earth Science 111 Final Exam

Front 1

Uniformitarianism

Back 1

The concept that geologic processes operating at present are the same processes that operate in the past

Front 2

Actualism

Back 2

In place of uniformitarianism. the term actualism comes closer to conveying the principle that the same processes and natural laws that operated in the past are those we can actually observe or infer from observation as operating at the present

Front 3

Numerical Age

Back 3

Also known as absolute age. Age given in years or some other unit of time

Front 4

Relative Time

Back 4

The sequence in which events took place

Front 5

Original Horizontality

Back 5

States that beds or dement deposited in water formed as horizontal or nearly horizontal layers

Front 6

Superposition

Back 6

States that within a sequence of undisturbed sedimentary or volcanic rocks, the oldest layer is at the bottom and layers are progressively younger upward in the stack

Front 7

Lateral Continuity

Back 7

States that an original sedimentary layer extends laterally until it tapers or tins at its edges

Front 8

Cutting Relationships

Back 8

States that a disrupted pattern is older than the cause of disruption

Front 9

Inclusion

Back 9

States that fragments included in a host rock are older than the host rock

Front 10

Unconformity

Back 10

Is a surface or contact that represents a gap in the geologic record, with the rock unit immediately above the contact being considerably younger than the rock beneath

Front 11

Disconformity

Back 11

The contact representing missing rock strata separates beds that are parallel to one another

Front 12

Angular Unconformity

Back 12

Is a contact in which younger strata overlie an erosion surface on tilted or folded layered rock

Front 13

Nonconformity

Back 13

Is a contact in which an erosion surface on plutonic or metamorphic rock has been covered by younger sedimentary or volcanic rock

Front 14

Physical Continuity

Back 14

Being able to trace physically the course of a rock unit is one way to correlate rocks between two different places

Front 15

Faunal Succession

Back 15

(William Smith) Allowed rock layers in different places to be correlated based on their fossils

Front 16

Index Fossil

Back 16

A fossil from a very short lived, geographically widespread species known to exist during a specific period of geologic time

Front 17

Standard Geologic Time Scale

Back 17

A worldwide relative time scale based on fossil assemblages, it subdivides geologic time

Front 18

Phanerozoic Eon

Back 18

(meaning visible life) is divided into three eras, which are divided into periods, which are, in turn, subdivided into epochs

Front 19

Precambrian

Back 19

denotes the vast amount of time that preceded the Paleozoic Era which begins with the Cambrian Period

Front 20

Paleozoic Era

Back 20

Meaning old life began with the appearance of complex life as indicated by fossils. Rocks older than Palaeozoic contain few fossils.

Front 21

Mesozoic Era

Back 21

Followed the Palaeozoic. On land, dinosaurs became the dominant animals of the Mesozoic.

Front 22

Holocene

Back 22

We live in the holocene or recent epoch of the Quaternary Period of the Cenozoic Era meaning new life

Front 23

Pleistocene Epoch

Back 23

Includes the most even ice ages

Front 24

Isotopic Dating

Back 24

Determining the age of a rock through its radioactive elements

Front 25

Half-Life

Back 25

The time is takes for one half of a given number of radioactive atoms to decay

Front 26

Hydrologic Cycle

Back 26

The movement and interchange of water between the ocean, atmosphere, and land

Front 27

Stream

Back 27

Is a body of running water that is confined in a channel and moves downhill under the influence of gravity

Front 28

Stream Channel

Back 28

A long narrow depression eroded by the stream into rock or sediment

Front 29

Sheetwash

Back 29

A thin layer of unchanneled water flowing downhill.

Front 30

Drainage Basin

Back 30

The total area drained by a stream and its tributaries

Front 31

Tributaries

Back 31

A small stream following in to a larger one

Front 32

Divide

Back 32

A ridge or a strip of high ground dividing one drainage basin from another

Front 33

Drainage Pattern

Back 33

A drainage pattern can in many cases reveal the nature and structure of the rocks underneath it

Front 34

Dendritic

Back 34

A tributaries join the main stream at an acute angle forming a v or y point downstream

Front 35

Radial Pattern

Back 35

in which streams diverge outward like shoes of a wheel forms on high conical mountains such as composite volcanoes and domes

Front 36

Rectangular Pattern

Back 36

in which tributaries have frequent 90-degree bends and tend to join other streams at right angles, develops o regularly fractured rock

Front 37

Trellis Pattern

Back 37

Consists of parallel main streams with short tributaries meeting them at right angles

Front 38

Stream Velocity

Back 38

The distance water travels in a stream per unit time

Front 39

Stream Gradient

Back 39

The downhill slope of the bed or of the water surface if the stream is very large

Front 40

Discharge

Back 40

Is the volume of water that flows past a given point in a unit of time is found by multiplying the cross-sectional area of a stream by its velocity

Front 41

Hydraulic Action

Back 41

Refers to the ability of flowing water to pick up and move rock and sediment

Front 42

Solution

Back 42

Although ordinarily slow can be an effective process of weathering and erosion

Front 43

Abrasion

Back 43

the grinding away of the stream channel by the friction and impact of the sediment load

Front 44

Potholes

Back 44

Are depressions that are eroded into the hard rock of a streamed by the abrasive action of the sediment load

Front 45

Bed Load

Back 45

Is the large or heavy sediment particles that travel on the streambed

Front 46

Saltation

Back 46

A series of short leaps or bounces off the bottom

Front 47

Suspended Load

Back 47

Is sediment that is light enough to remain lifted indefinitely above the bottom by water turbulence

Front 48

Dissolved Load

Back 48

Soluble products of chemical weathering processes can make up substantial dissolved load in a stream

Front 49

Bar

Back 49

A ridge of sediment usually sand and gravel deposited in the middle or along the banks of a stream

Front 50

Braided Stream

Back 50

The stream may fill its main channel with sediment and become a braided stream flowing in a network of interconnected rivulets around numerous bars

Front 51

Meanders

Back 51

Rivers that carry fine grained silt and clay in suspension tend to be narrow and deep and to develop pronounced sinus curves

Front 52

Point Bar

Back 52

Consists of a series of arcuate ridges of sand or gravel

Front 53

Meander Cutoff

Back 53

A new shorter channel across the narrow neck of a meander

Front 54

Flood Plain

Back 54

Is a broad strip of land built up by sedimentation on either side of a stream channel

Front 55

Natural Levees

Back 55

A series of floods may build up low ridges or flood deposited sediment that form on either side of a stream channel and thin away from the channel

Front 56

Delta

Back 56

A stream flowing into quiet water usually builds a delta, a body of sediment deposited at the mouth of a river when the rivers velocity decreasess

Front 57

Distribitutaries

Back 57

Small shifting channels that carry water away from the main river channelling and distribute it over the surface of the delta

Front 58

Alluvial Fan

Back 58

Is a large fan or cone shaped pile of sediment that usually forms where a streams velocity decreases as it emerges from a narrow mountain canyon onto a flat plane

Front 59

Downcutting

Back 59

The process of deepening a valley by erosion of the streamed

Front 60

Base Level

Back 60

The limit of downcutting, it is a theoretical limit for erosion of the earths surface

Front 61

Graded Stream

Back 61

is one that exhibits a delicate balance between its transporting capacity and the sediment load available to it

Front 62

Lateral Erosion

Back 62

A graded stream can be deepening its channel by downcutting while part of its energy is also widening the valley by lateral erosion, the erosion and undercutting of streams banks and valley walls as the stream swings from side to side across its valley floor

Front 63

Headward Erosion

Back 63

The slow uphill growth of a valley above its original source through gullying, malls wasting and sheet erosion

Front 64

Stream Terraces

Back 64

are steplike landforms found above a stream and its flood plain

Front 65

Incised Meanders

Back 65

Are meanders that retain their sinuous patter as they cut vertically downward below the level at which they originally formed

Front 66

Groundwater

Back 66

The water that lies beneath the ground surface filling the pore space between grains in bodies of sediment and clastic sedimentary rock and filing cracks and crevices in all types of rock

Front 67

Saturated Zone

Back 67

The subsurface zone in which all rock openings are filed with water

Front 68

Water Table

Back 68

The water level inside the well marks the upper surface of the saturated zone this surface is the water table

Front 69

Unsaturated Zone

Back 69

Above the water table where not all the sediment or rock openings are filled with water

Front 70

A perched Water Table

Back 70

is the top of a body of groundwater separated from the main water table beneath it by a zone that is not saturated

Front 71

Porosity

Back 71

The percentage of rock or sediment that consists of voids or openings is a measurement of a rocks ability to hold water

Front 72

Permeability

Back 72

Refers tot eh capacity of a rock to transit a fluid such as water or petroleum through pores and fractures

Front 73

Aquifer

Back 73

Is a body of saturated rock or sediment through which water can move easily

Front 74

Unconfined Aquifer

Back 74

Which has a water table because it is only partly filled with water

Front 75

Confined Aquifer

Back 75

Is completely filled with water under pressure and is usually separated from the surface by a relatively impermeable confine bed, or aquitard such as shalae

Front 76

Well

Back 76

Is a deep hole generally cylindrical that is dug or drilled into the ground to penetrate an aquifer within the saturated zone. Usually water that flows into the well from the saturated rock must be lifted or pumped to the surface

Front 77

Recharge

Back 77

The addition of new water to the saturated zone

Front 78

Spring

Back 78

Is a place where water flows naturally from rock onto the land surface

Front 79

Gaining Streams

Back 79

They receive water from the saturated zone

Front 80

Losing Streams

Back 80

They are losing water to the saturated zone

Front 81

Stalactites

Back 81

Are iciclelike pendants of dripstone hanging form cave ceilings

Front 82

Stalagmites

Back 82

Are cone shaped masses of stalactites

Front 83

Karst Topography

Back 83

In areas where groundwater dissolves carbonate rock a distinctive landscape may develop

Front 84

Petrified Wood

Back 84

Which develops when porous buried wood is either filed in or replaced by inorganic silica carried in by groundwater

Front 85

Concretion

Back 85

Develops typically around an organic nucleus such as a leaf tooth or other fossil

Front 86

Geodes

Back 86

Are partly hollow globe shaped bodies found in some limestones and locally in other rocks

Front 87

Geyser

Back 87

Is a type of hot spring that periodically erupts hot water and steam

Front 88

Compressive

Back 88

results in rocks being shortened or flattened

Front 89

Tensional Stress

Back 89

Is caused by forces pulling away from one another in opposite directions results in stretching or extension of material

Front 90

Shear Stress

Back 90

It is mic like putting a deck of cards in your hands and shearing the deck by moving your hands in opposite directions results in a shear strain parallel to the direction of the stresses

Front 91

Elastic Limit

Back 91

Once the stress applies exceeds the elastic limit the rock will deform in a permanent way just as the runner band will break if stretched to far

Front 92

Ductile

Back 92

will bend while under stress and does not return to its original shape after the stress is removed

Front 93

Brittle

Back 93

will fracture at stresses higher than its elastic limit or once the stresses are greater than the strength of the rock

Front 94

Geologic Map

Back 94

Uses standardized symbols and patterns to represent rock types and geologic structures is typically produced form the field map for a given area

Front 95

Strike

Back 95

Is the compass direction of a line formed by the intersection of an inclined plane with a horizontal plane

Front 96

Angle of Dip

Back 96

is measure downward from the horizontal plane to the bedding plane

Front 97

Direction of Dip

Back 97

is the compass direction in which the angle of dip is measured

Front 98

Geologic Cross section

Back 98

represent a vertical slice through a portion of Earth

Front 99

Structural Dome

Back 99

Is a structure in which the beds dip away from a central point and the oldest rocks are found in the core of the structure

Front 100

Structural Basin

Back 100

the beds dip toward a central point and the youngest rocks are exposed in the centre of the structure

Front 101

Faults

Back 101

are fractures in bedrock along which sliding has taken place

Front 102

Hangin wall

Back 102

The side of the fault above the inclined fault surface

Front 103

Footwall

Back 103

The side below the fault

Front 104

Reverse Fault

Back 104

the hanging wall block has moved up relative to the footwall fault

Front 105

Focus

Back 105

The point in which the seismic waves first originate

Front 106

Epicenter

Back 106

The point on earths surface directly above the focus

Front 107

Body Waves

Back 107

Are seismic waves that travel through the earths interior spreading outward from the focus in all directions

Front 108

Surface Waves

Back 108

Are seismic waves that travel on Earth's surface away from the epicentre like water waves spreading out from a pebble thrown into a pond

Front 109

P Wave

Back 109

is a compressional or longitudinal wave in which rock vibrates back and forth parallel to the direction of wave propagation

Front 110

Love Waves

Back 110

are most like S waves that have no vertical displacement

Front 111

Rayleigh Waves

Back 111

Behave like rolling ocean waves cause the ground to move in elliptical path opposite to the direction the wave passes tend to be incredibly destructive to buildings because they reproduce more ground movement and take longer passes

Front 112

Seismograph

Back 112

Is a recording device that produces a permanent record of Earth motion detected by a seisnometer

Front 113

Seismogram

Back 113

Can be used to measure the strength of the earthquake

Front 114

Travel Time Curve

Back 114

The increase in P-S values interval is regular with increasing distance for several thousand kilometres which plots seismic wave arrival time against distance

Front 115

Depth of Focus

Back 115

The distance between focus and epicentre for earthquakes

Front 116

Modified Mercalli Scale

Back 116

Represented in roman numerals, higher numbers indicate greater damage

Front 117

Magnitude

Back 117

It is a measure of the energy released during the earthquake

Front 118

Richter Scale

Back 118

Magnitude is reporting on this scale

Front 119

Moment Magnitude

Back 119

Is the most objective way of measuring the energy released by the large earthquake

Front 120

Circum Pacific Belt

Back 120

Is the most important concentration of earthquake by far

Front 121

Mediterranean Himalayan Belt

Back 121

Major concentration for earth quakes

Front 122

Benioff Zones

Back 122

Zones that inclined seismic activity

Front 123

Island Arc

Back 123

Benioff Zones slope under a continent or a curved line of islands

Front 124

Seismac Refraction

Back 124

A method used to locate rock boundaries. The bending of seismic waves as they pass from one material to another which is similar to the way that light appears to sharply bend a straw resting in a glass of water

Front 125

P-Wave Shadow Zone

Back 125

The region between 103 degrees and 142 degrees which lacks p-waves

Front 126

S Wave Shadow Zone

Back 126

Is larger than the p-wave shadow

Front 127

Isostasy

Back 127

Is a balance or equilibrium of adjacent blocks of brittle lithosphere floating on the asthenosphere

Front 128

Crustal Rebound

Back 128

This rise of the crustal lithosphere after the removal of the ice

Front 129

Gravity Meter

Back 129

A useful tool for studying the crust and upper mantle which measures the gravitational attraction between earth and a mass within the instrument

Front 130

Positive Gravity Anomaly

Back 130

Gravity reading higher than the normal regional gravity

Front 131

Negative Gravity Anomaly

Back 131

A gravity reading lower than the normal regional gravity

Front 132

Magnetic Reversal

Back 132

A change in the polarity of the magnetic field

Front 133

Curie Point

Back 133

As the lava cools slowly below the curie point this magnetic record is permanently trapped in the rock

Front 134

Paleomagnetism

Back 134

The study of ancient magnetic fielsds

Front 135

Geomagnetic polarity time scale

Back 135

A record of all the geomagnetic reversals that have occurred over the last 200 million years is well preserved within the oceanic crust and forms the basis

Front 136

Magnetometer

Back 136

Is an instrument used to measure the strength of Earths magnetic field

Front 137

Positive magnetic Anomaly

Back 137

Is a readign of magnetic field of strength that is higher than the regional average

Front 138

Negative Magnetic Anomly

Back 138

is a reading of magnetic field strength that is lower than the regional average

Front 139

Geothermal Gradient

Back 139

the temperature increase with the depth into earth

Front 140

Heat Flow

Back 140

A small but measurable amount of heat from earths interior is being lost gradually through the surface

Front 141

Craton

Back 141

Region of a continent that has been structurally stable for a prolonged period of time

Front 142

Precambrian Shield

Back 142

A complex of precambrian metamorphic and plutonic rocks exposed over a large area

Front 143

Lithospheric Delimitation

Back 143

Used to explain the block-faulting thin curst and geologically young volcanic activity of the basin and range

Front 144

Tectonostratigraphic Terranes

Back 144

Regions within which there is geologic continuity

Front 145

Suspect Terranes

Back 145

Have rock types and ages that do not seem related to the rest of the geology of the mountain belt

Front 146

Accreted Terrane

Back 146

If evidence indicates that a terrane did not form at its present site on a continent

Front 147

Nonrenewable Resources

Back 147

They form very slowly often over millions of years under unusual conditions in restricted geographic settings

Front 148

Resource

Back 148

The term used to describe the total amount of any given geologic material of potential economic interest whether developed or not

Front 149

Reserve

Back 149

Is the term used to describe the portion of a resource that has been discovered of inferred

Front 150

Kinetic Energy

Back 150

Involves movement

Front 151

Potential Energy

Back 151

is stored energy

Front 152

Energy Resources

Back 152

Are the materials we use to produce heat and electricity or as fuel for transport

Front 153

Fossil Fuels

Back 153

Coal petroleum natural gas and propane