Geology 101 Lab Final

Front 1

topographic map

Back 1

map showing the shape of the land

Front 2

map scale

Back 2

relation between distance on the map to the true distance on the Earth's surface

Front 3

Fractional Scale (map scale)

Back 3

1/24,000 or 1:24000 = distance of 1 unit on the map represents a distance of 24,000 of the same units on Earth

Front 4

Graphic/Bar Scale (map scale)

Back 4

bar divided into segments that show relation between distance on map to actual distance on Earth
- useful for measuring distance between points

Front 5

latitude

Back 5

parallel lines to the N and S

Front 6

longitude

Back 6

meridians to the W and E

Front 7

measurements of longitude and latitude

Back 7

degrees, minutes, seconds
60 seconds = 1 minute
60 minutes = 1 degree

Front 8

contour line

Back 8

line that connects all points of equal elevation
- usually measured from sea level
- smallest interval possible

Front 9

contour interval

Back 9

vertical distance in elevation between adjacent contour lines

Front 10

slope

Back 10

vertical change in elevation per horizontal distance

Front 11

steep slope

Back 11

contour lines that are close together

Front 12

relief

Back 12

difference in elevation between two points on a map

Front 13

total vs. local relief

Back 13

total = difference between highest and lowest points
local = difference between two specific points

Front 14

contour lines crossing a stream

Back 14

peak upstream

Front 15

what do topographic map depict that normal maps do not?

Back 15

elevation of the land

Front 16

groundwater

Back 16

water that percolates through the ground

Front 17

surface water

Back 17

water that flows over the ground (streams and ponds)

Front 18

base flow

Back 18

grounwater that seeps into a stream via porous rock, fractures, springs (opposite of groundwater)

Front 19

perennial streams

Back 19

flow continuously throughout the year

Front 20

intermittent streams

Back 20

flow only at certain times
- rainy seasons
- snow melts

Front 21

flood

Back 21

when streams overflow their banks

Front 22

land erosion

Back 22

wearing away of the land
- streams do this more than anything else

Front 23

alluvium

Back 23

gravel, sand, silt, clay deposited in floodplains, point bars, alluvial fans, etc.
- transported + deposited sediment

Front 24

sheet flow

Back 24

water that flows over the ground before it can seep in
- flow downslope via gravity

Front 25

stream drainage system

Back 25

tributaries to streams to rivers

Front 26

dendritic pattern

Back 26

branches of a tree
- tributaries
- homogenous rocks

Front 27

rectangular pattern

Back 27

right-angle bends that form pattern of interconnected rectangles + squares
- rocks fractured in 2 main directions

Front 28

radial pattern

Back 28

flowing outward from a central area
- conical hills, volcanoes

Front 29

centripetal pattern

Back 29

converge on center point
- lake

Front 30

annular pattern

Back 30

incomplete, concentric rings of streams connected by short radial channels

Front 31

trellis pattern

Back 31

vine
- main stream is long + intersected at right angles by tributaries
- alternating layers of resistant and nonresistant rock

Front 32

deranged pattern

Back 32

random channels

Front 33

drainage basin

Back 33

entire area of land drained by one stream

Front 34

drainage basin divides

Back 34

linear boundaries separating basins
- usually hills

Front 35

weathering

Back 35

streams physically erode + disintegrate materials or chemically decompose minerals

Front 36

transportation

Back 36

weathered materials transported downstream

Front 37

deposition

Back 37

velocity of stream drops so particles settle out or part of stream evaporates

Front 38

uplands

Back 38

highest elevation of streams
- head/source
- erosion dominant process

Front 39

differential erosion

Back 39

resistant = hard, chemically resistant form ridges or hilltops
nonresistant = soft, more easily weathered form valleys

Front 40

mouth

Back 40

end of river valley
- enters lake, ocean, dry basin
0 alluvial fans or deltas

Front 41

how geology affects rivers

Back 41

affects stream's ability to erode

Front 42

how gradient affects rivers

Back 42

steepness of slope (ft per mile)
- dividing verticle rise or fall between two points on slope by horizontal distance

Front 43

how base level affects rivers

Back 43

lowest level to which a stream can theoretically erode
- mouth
- deposition because velocity is zero

Front 44

how discharge affects rivers

Back 44

rate of stream flow at given time + location

Front 45

how load affects rivers

Back 45

amounth of material that is transported by a stream

Front 46

change from headwater to mouth of stream

Back 46

- gradient decreases
- discharge increases
- load increases
- valleys widen

Front 47

floodplains

Back 47

alluvium accumulates landward of river banks during flooding

Front 48

levees

Back 48

higher than the rest of the floodplain

Front 49

yazoo tributary

Back 49

tributary that can't breach a river's levee
- flows parallel to river

Front 50

meandering channels

Back 50

winding rivers usually farther downstream
- cutbanks + points bars
- ox bow lakes
- migrate over time

Front 51

cutbank

Back 51

erosion on outer side of meandering channels

Front 52

point bar

Back 52

depoits of gravel + sand along the inner edge of meanders

Front 53

oxbow lake

Back 53

outer edge of meader cut off by new path of river
- crescent shaped

Front 54

braided stream patterns

Back 54

channels that are interconnected

Front 55

delta/alluvial fan

Back 55

stream drops its sediment load because velocity drops dramatically

Front 56

mass wastage

Back 56

downslope movement of Earth materials
- soil, rock
- steep slopes

Front 57

Where do streams generally carry a greater % load of sediment in terms of gradient?

Back 57

gentle gradient

Front 58

stress

Back 58

force thta acts on a rock unit to change its shape or volume

Front 59

compressional stress

Back 59

shorten a rock body

Front 60

tensional stress

Back 60

elongate or pull apart a rock body

Front 61

shear stress

Back 61

bend or break a rock

Front 62

plastic deformation

Back 62

stress applied exceeds rock's strength
- high temperatures + pressures
- permanent change in rock

Front 63

fold

Back 63

wavelike undulation
- produced by plastic deformation

Front 64

fault

Back 64

movement of rocks on either side of fracture

Front 65

joint

Back 65

break in rock but not displacement

Front 66

strike

Back 66

trend
- compass direction of line produced by intersection of inclined rock layer with horizontal surface plane
- angle relative to N
- N 10 degrees E

Front 67

dip

Back 67

angle of inclination of surface of rock from horizontal plane
- angle + direction of inclination
- 90 degree angle to strike
- teeny line in correct direction and degree marking

Front 68

folds

Back 68

formerly flat rocks compressed into series of waves

Front 69

anticlines

Back 69

arch
- rock layers dip away from axial plane
- erosion -> oldest rock layers exposed

Front 70

synclines

Back 70

downfolds/troughs
- layers dip toward axial plane
- erosion -> youngest rock layers exposed

Front 71

axial plane

Back 71

imaginary plane drawn through long axis of fold that divides it as equally as possible

Front 72

limbs

Back 72

two halves of axial planes

Front 73

symmetrial folds

Back 73

limbs are mirror images
- same angle

Front 74

asymmetrical fold

Back 74

limbs have different angles of dip

Front 75

overturned fold

Back 75

fold where one limb is tilted beyond vertical

Front 76

dip-slip fault

Back 76

vertical movement of rock layers

Front 77

strike-slip fault

Back 77

horizontal movement

Front 78

hanging wall

Back 78

- dip-slip fault
- angle sticks out on top
- workers would hang tools

Front 79

footwall

Back 79

- dip-slip fualt
- angle sticks out on bottom
- worker would stand here

Front 80

normal fault

Back 80

hanging wall drops down
- tensional forces

Front 81

reverse fault

Back 81

hanging wall pushed upwards
- compressional forces

Front 82

right-lateral vs. left-lateral stirke-slip faults

Back 82

depends on relative motion of blocks

Front 83

submergent coastline
- retrogradational
- transgression
- subsidence

Back 83

caused by rising sea level
- flooding + receding (retrogradational)
- water level actually rising (transgression)
- land getting lower (subsidence)

Front 84

emergent coastline
- progradational
- regression
- uplift

Back 84

caused by falling sea level
- elevated about sea level and buildign out into the water (progradational)
- water level falling (regression)
- land rising (uplift)

Front 85

barrier island

Back 85

long, narrow island that parallels the mainland coastline
- separated by lagoon, tidal flat, salt marsh

Front 86

beach

Back 86

gently sloping deposit of sand or gravel along edge of shoreline

Front 87

berm crest

Back 87

highest part of beach

Front 88

washover fan

Back 88

fan-shaped deposit of sand moved landward of beach during storm or very high tide

Front 89

estuary

Back 89

river valley flooded by rise in level of ocean

Front 90

longshore current

Back 90

water current in surf zone
- flows parallel to shoreline driven by waves caused by wind

Front 91

delta

Back 91

sediment deposit at mouth of river where it enters an ocean or lake

Front 92

headland

Back 92

projection of land that extends into ocean or lake
- cliffs

Front 93

spit

Back 93

sand bar extending from end of beach into mouth of adjacent bay

Front 94

tidal flat

Back 94

muddy or sandy area covered with water at high tide but exposed at low tide

Front 95

saltmarsh

Back 95

marsh that is flooded by ocean water at high tide

Front 96

wave-cut cliff

Back 96

seaward-facing cliff along steep shoreline
- caused by wave erosion

Front 97

wave-cut platform

Back 97

bench at sea level along steep shore
- caused by wave erosion

Front 98

marine terrace

Back 98

elevated platform that is bounded on its seaward side by cliff or steep slope

Front 99

stack

Back 99

isolated orcky island near headland cliff

Front 100

tombolo

Back 100

sandbar that connects island with mainland or other island

Front 101

tied island

Back 101

island connected to mainland by tombolo

Front 102

sea wall

Back 102

boulders etc. constructed against a shoreline to prevent erosion

Front 103

breakwater

Back 103

offshore wall constructed parallel to shoreline to break waves
- sand accumulates + beach widens because no longshore current

Front 104

groin

Back 104

short wall perpendicular to shoreline that traps sand
- up-current side accumulates sand

Front 105

jetties

Back 105

long walls etending from shore to protect inlets + harbors
- come in pairs