Geology Ch 21-23

Front 1

a region so dry that it contains no permanent streams and very little vegetation

Back 1

desert

Front 2

dry

Back 2

arid

Front 3

a wavering pool of light on the ground

Back 3

mirage

Front 4

the dry air found on the leeward side of a mountain due to rain catching on the seaward side.

Back 4

rain shadow

Front 5

dark rusty brown coating of iron oxide, manganese oxide and clay that cover rocks in the desert

Back 5

desert varnish

Front 6

symbols and pictographic figures cut into desert varnish

Back 6

petroglyphs

Front 7

dry stream channels in desert regions

Back 7

dry washes or arroyos

Front 8

fine grained sediment such as dust and silt held in suspension

Back 8

suspended load

Front 9

moderate to strong winds can roll and bounce sand grains along the ground - a process called...

Back 9

saltation

Front 10

saltating sand consitutes the winds....

Back 10

surface load

Front 11

an accumulation of coarser sediment left behind when fine-grained sediment blows away

Back 11

lag deposit

Front 12

a natural formation of separate strones that fit together tightly

Back 12

desert pavement

Front 13

rocks whose surface has been faceted by the wind are faceted rocks

Back 13

ventifacts

Front 14

where resistant rocks overlies softer rock wind abrasion can create mushroom like columns with the resistant rock on top

Back 14

yardangs

Front 15

the process of lowering the land surface by wind erosion

Back 15

deflation

Front 16

the shape of the land surface twists the wind into a turbulent vortex that causes enough deflation to scour a deep bowl-like depression

Back 16

blowout

Front 17

debris of rock that acumulate at the base of a hill

Back 17

talus apron

Front 18

a fan of distributaries spreads the sediment in a wedge shape

Back 18

alluvial fan

Front 19

alluvial fas that overlap and form an elongate wedge of sediment

Back 19

bajada

Front 20

a flat dry lake bed

Back 20

playa

Front 21

a basin with no outlet to the sea

Back 21

interior basin

Front 22

dust that accumulates forming layers of finegrained sediment

Back 22

loess

Front 23

sand in piles

Back 23

dunes

Front 24

when cliffs erodebut the cliff face retreats but retains roughly the same form

Back 24

cliff retreat

Front 25

large plateaus of rock with a top surface area of several square km

Back 25

mesa

Front 26

medium sized plateau

Back 26

butte

Front 27

small examples of plateaus

Back 27

chimney

Front 28

where bedding dips at an angle to horizontal, flat topped mesas and buttes dont form, asymmetric ridges form instead

Back 28

cuestas

Front 29

when the bedding dip is steep to near vertical , a narrow symmetrical ridge

Back 29

hogback

Front 30

when all that remains of a cliff is a small island of rock surrounded by alluvium filled basins its called

Back 30

inselberg

Front 31

bedrock surfaces that extend outward like ramps from the steep cliffs of a mountain range on one sides to an alluvium filled valley on the other

Back 31

pediment

Front 32

plants that store water for long periods of time

Back 32

succulents

Front 33

process of transforming nondesert areas to desert

Back 33

desertification

Front 34

boulders that are out of place and seem to have traveled a great distance to their resting place

Back 34

erratics

Front 35

slowly flowing masses of ice that survive the summer melt

Back 35

glaciers

Front 36

vast glaceirs that had one covered much of the continent

Back 36

ice sheets

Front 37

time when the climate was significantly colder

Back 37

ice age

Front 38

something that reflects light well (like ice)has a high

Back 38

albedo

Front 39

glaciers that exist near a mountain range

Back 39

mountain glaciers

Front 40

glacers that fill bowl-shaped depressions

Back 40

cirques

Front 41

vast ice sheets that spread over thousands of sq km of continental crust

Back 41

continental glaciers

Front 42

glaciers that form where atmospheric temperatures become high enough druing a substantial portion of th year for the glacial ice to be at or near its melting point

Back 42

temperate glaciers

Front 43

glaciers that occur in regions where atmospheric temps stay so low that the ice is frozen almost permanently

Back 43

polar glaciers

Front 44

evaporate directly into vapor

Back 44

sublimate

Front 45

packed granular material (snow about to form a glacier)

Back 45

firn

Front 46

basal sliding is the basic mode of movement of this type of glacier

Back 46

wet-bottom glacier

Front 47

internal flow is the dominate type of movement of this type of glacier

Back 47

dry-bottom glacier

Front 48

a large crack in the ice

Back 48

crevasse

Front 49

when a glacier moves faster for a short period of time

Back 49

surge

Front 50

removal of ice by sublimation

Back 50

ablation

Front 51

snowfall that is added to a glacier in a specific area

Back 51

zone of accumulation

Front 52

area where sublimation occurs

Back 52

zone of ablation

Front 53

boundary between the zone of acuumulation and the zone of ablation

Back 53

equilibrium line

Front 54

leading edge or margin of a glacier

Back 54

toe

Front 55

if the rate of ice that accumulates excedds the rate of ablation then ______ occurs

Back 55

glacial advance

Front 56

if the rate of ablation exceeds the rate of accumulation

Back 56

glacial retreat

Front 57

continental glaciers that enter the sea become

Back 57

ice shelves

Front 58

floating chunk of ice

Back 58

iceberg

Front 59

when the surface of the sea itself freezes

Back 59

sea ice

Front 60

larger rocks that drop from the ice to the sea floor

Back 60

drop stones

Front 61

when glaciers are abraded(rasped) by sand

Back 61

glacially polished surfaces

Front 62

rasping by large clasts

Back 62

glacial striations

Front 63

when a cirque melts it forms a

Back 63

tarn

Front 64

a ridge of rock separating 2 adjacent cirques

Back 64

arete

Front 65

a pointed mountain peak surrounded by at least 3 cirques

Back 65

horn