Geol 101L 2

Front 1

topographic map

Back 1

map that uses contour lines to show landforms

Front 2

aerial photographs

Back 2

photographs taken from a plane and pieced together to form a mosaic of an area

Front 3

landsat images

Back 3

made by a satellite that takes digital images of earth's surface using visible light and other wavelengths of the electromagnetic spectrum

Front 4

digital elevation models

Back 4

computer generated, 3D views of landforms made from radar satellite elevation data spaced at intervals on the earth's surface

Front 5

projection

Back 5

the process by which a 3D sphere is converted into a 2D map

Front 6

prime meridian

Back 6

a longitudinal line that passes through Greenwich, England

Front 7

azimuth method

Back 7

geologists use this to indicate direction, based on the dial of a compass

Front 8

map scale

Back 8

indicated how much an area has been scaled down so we can relate inches or centemeters on the map to real distances on the ground

Front 9

verbal scale

Back 9

uses words to describe the scaling of map and real distances

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proportional scale

Back 10

a scale that tells exactly how much ground has been scaled down to make the map (ex - 1:100,000)

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bar scale

Back 11

expresses the same relation as a verbal scale

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vertical exaggeration

Back 12

the degree to which the vertical scale has been exaggerated

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contour lines

Back 13

a line that connects points of the same value for whatever is being measured

Front 14

relief

Back 14

difference in elevation

Front 15

topographic profile

Back 15

a cross section view of topography

Front 16

stream channel

Back 16

the area within which the water is actually flowing

Front 17

stream valley

Back 17

region within which the stream has eroded the land

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headwaters

Back 18

where the stream begins

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mouth

Back 19

where the streams ends, by flowing into another stream, ocean, or topographic low

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base level

Back 20

the elevation at the mouth thus controls erosion along the entire stream

Front 21

sinuosity

Back 21

measures how much a stream meanders

Front 22

floodplain

Back 22

sediment carried by the floodwater is deposited in this

Front 23

natural levees

Back 23

ridges of sediment that outline the channel and form when a stream overflows its banks and deposits its coarsest sediment next to the channel

Front 24

point bars

Back 24

form when water on the inside of a meander loop slows down, causing sediment to be deposited

Front 25

meander scars

Back 25

the levees that formerly flanked the meanders help outline the former position of the river, leaving these

Front 26

oxbow lakes

Back 26

meander scars that have filled with water

Front 27

drainage basin

Back 27

the area drained by a stream

Front 28

drainage divide

Back 28

highlands that separate adjacent drainage basins

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dendritic

Back 29

stream pattern that develops where surface materials are equally resistant to erosion

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trellis

Back 30

stream pattern that forms where ridges of resistant rock alternate with valleys underlain by weaker material

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rectangular

Back 31

stream patterns that indicate zones of weakness perpendicular to one another

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radial

Back 32

stream pattern that flow either outward from a high point or inward toward the center of a large basin

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annular

Back 33

stream pattern that occurs where there are concentric rings of alternating resistant and weak rocks, typically found in domes and basins

Front 34

mountain, valley, or alpine glaciers

Back 34

small glaciers that form on mountains and flow downhill, carrying out their erosion and depositional work in the valleys they carve

Front 35

continental ice sheets

Back 35

masses of ice thousands of feet thick, that flow across the countryside

Front 36

till

Back 36

sediment that is deposited directly from melting ice

Front 37

outwash

Back 37

sediment that is carried away by melt water

Front 38

moraines

Back 38

landscapes that are composed of till deposited directly from the melting ice

Front 39

outwash plains and eskers

Back 39

landscapes that are made of outwash carried by meltwater streams

Front 40

paternoster lakes

Back 40

lakes that form on an irregular, scalloped glacial valley

Front 41

hanging valley

Back 41

when large glaciers carve downward more rapidly than smaller ones so previously existing main stream valleys are deepened more than tributary valleys; when the ice melts it creates this

Front 42

groundwater

Back 42

water that sinks into the ground

Front 43

karst topography

Back 43

ground-water eroded landscapes

Front 44

aquifers

Back 44

materials that transmit water readily

Front 45

aquitards

Back 45

materials that prevent water from infiltrating

Front 46

cone of depression

Back 46

when water is pumped from an aquifer it lowers the water table, especially in the area around the well

Front 47

alluvial fans

Back 47

streams erode materials from the highlands and redeposit them as these

Front 48

inselberg

Back 48

isolated peaks above sediment fill

Front 49

playa lake

Back 49

streams flowing into the basin from surrounding blocks have no way to leave and so form this

Front 50

salt lakes

Back 50

playa lakes that evaporate

Front 51

wave base

Back 51

when the depth of wave action is limited and is approximately half of the wavelength it is called this

Front 52

emergent

Back 52

recently uplifted relative to sea level

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submergent

Back 53

lowered so that former land areas are below sea level

Front 54

wave cut bench

Back 54

waves that move sediment back and forth across the tidal zone, creating this flat thing

Front 55

storm surge

Back 55

a wall of water driven onshore by the hurricane

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pressure

Back 56

squeezing equally from all sides

Front 57

compression

Back 57

squeezing of squashing in a specific direction

Front 58

tension

Back 58

stretching or pulling apart

Front 59

shear

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happens when one part of the material moves relative to another part in a direction parallel to the boundary between the parts

Front 60

deformation

Back 60

the application of stress to rock produces this

Front 61

faults

Back 61

displacement of rocks on sliding surfaces

Front 62

folds

Back 62

bending or warping of layers to produce arch like or trough like shapes

Front 63

foliation

Back 63

a fabric caused by the alignment of platy or elongate minerals

Front 64

geologic structures

Back 64

the products of deformation, such as faults, folks, and foliations are called these

Front 65

block diagram

Back 65

3D representation of a region of the crust that depicts the configuration of structures on the ground

Front 66

geologic map

Back 66

represents the earth's surface as it would appear looking straight down from above, showing the boundaries between rock units and where structures intersect the earth's surface

Front 67

cross section

Back 67

represents the configuration of structures as seen in a vertical slice through the earth

Front 68

contact

Back 68

the boundary between two geologic units

Front 69

stratigraphic formation

Back 69

a sequence of sedimentary and/or volcanic layers that has a definable age and can be identified over a broad region

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intrusive contact

Back 70

boundary of surface of an intrusive igneous rock

Front 71

conformable contact

Back 71

boundary between successive beds, sedimentary formations, or volcanic extrusions in a continuous stratigraphic sequence

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uncomformable contact

Back 72

occurs where a period of erosion and/or deposition has interrupted deposition

Front 73

fault contact

Back 73

where two units are juxtaposed across a fault

Front 74

attitude

Back 74

orientation of any planar geologic feature

Front 75

strike

Back 75

the intersection between a horizontal surface and the surface of the feature

Front 76

dip

Back 76

angle of tilt or the angle of slope of the bed

Front 77

body waves

Back 77

the energy of earthquakes that is brought to the surface by these seismic waves

Front 78

focus

Back 78

the point beneath the surface where the energy is released

Front 79

epicenter

Back 79

the point on the surface directly above the focus

Front 80

p-waves

Back 80

a form of longitudinal wave in which particles vibrate back and forth in the direction in which the wave is traveling (faster than the other kind of waves)

Front 81

s-waves

Back 81

form of transverse wave in which particle motion is perpendicular to the direction of energy transport

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surface waves

Back 82

when p or s waves reach the surface, some of their energy is converted to these

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love wave

Back 83

transverse wave in which particles vibrate horizontally

Front 84

rayleigh wave

Back 84

unique wave in which particles move in a circular pattern opposite the direction in which the wave is traveling

Front 85

seismometers

Back 85

instruments that detect seismic waves

Front 86

seismogram

Back 86

the printed or digital record of ground motion

Front 87

liquifaction

Back 87

a process by which seismic vibration causes friction between sand grains in waterlogged sediment to be reduced to the sediment loses its ability to support overlying weight and flows like a liquid

Front 88

half life

Back 88

the amount of time it takes for half of the parent atoms in a mineral sample to decay to an equal number of daughter atoms

Front 89

nonplunging fold

Back 89

when the hinge of a fold is horizontal

Front 90

plunging fold

Back 90

when the hinge of a fold has a tilt

Front 91

reverse fault

Back 91

if the hanging wall block moves up dip

Front 92

normal fault

Back 92

if the hanging wall block moves down dip

Front 93

uncomformity

Back 93

a contact that represents a period of nondeposition and/or erosion

Front 94

discomformity

Back 94

bedding above and below the unconformity are parallel but there is a significant time gap between the age of the strata below and the age of the strata above

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noncomformity

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strata are deposited on a basement of intrusive igneous and/or metamorphic rock

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angular uncomformity

Back 96

the orientation of the beds above and the uncomformity is not the same as that below

Front 97

structurally controlled landscape

Back 97

region in which the structure of bedrock strongly influences topography

Front 98

permeability

Back 98

the connection of pore space

Front 99

sinkholes

Back 99

form when underground cavities dissolved by groundwater grow so large that there is not enough rock to support the ground surface

Front 100

karst towers

Back 100

what remains when the rock around them has been dissolved

Front 101

karst valleys

Back 101

form when several sinkholes develop along an elongate fracture

Front 102

zone of saturation

Back 102

where all pore spaces are filled with water

Front 103

zone of aeration

Back 103

where some pores are partly filled with air