ABCs of Geomorphological Landforms and Features

Question 1

Formed when weathering, together with mass collapse (and in arid areas with wind erosion), creates a tunnel through a slab of rock.

Answer 1

Rock arch (bridge) and window

Question 2

A wind-eroded depression in the side of a cliff of a homogenous rock type.

Answer 2

Alcoves and yardang windows

Question 3

Low, triangular-shaped deposits built from the accumulation of sediments deposited at the mouth of a valley (i.e., from a mountains or upland into a larger mainstream valley or lowland)

Answer 3

Alluvial fan

Question 4

Roughly circular or oval in plan and have surface exposure of over 100 km^2 and it is deep-seated and are usually composed of coarse-grained plutonic rocks.

Answer 4

Batholiths lopoliths, and stock

Question 5

Submarine, circular, steep-sided holes which occur in coral reefs.

Answer 5

Blue hole

Question 6

Shake hole, swallow hole, swallet, doline, or cenote

Answer 6

Sinkhole

Question 7

A compound alluvial fan where neighboring alluvial fans convere into a single apron of deposits against a slope. It may hold very shallow lakes called playas.

Answer 7

Bajada

Question 8

A small steep-sided and flat-topped hill, built of flat lying soft rocks capped by a more resistant layer of sedimentary rock, lava flow or duricust, surrounded by a plain.

Answer 8

Butte

Question 9

A deeply incised, steep-sided river valley.

Answer 9

Canyon

Question 10

An asymmetrical upland feature usually associated with gently dipping rocks and comprising a steep scarp slope (or escarpemnt) and a longer, gentler dip slope.

Answer 10

Cuesta

Question 11

Also a pericline; formed by tectonic warping, igneous intrusion, or diapir

Answer 11

Dome

Question 12

A depositional landform produced by sedimentation at and around the mouth of a river; river-, tide-, wave-dominated.

Answer 12

Delta

Question 13

A large area of sand dunes

Answer 13

Erg

Question 14

A long winding ridge of stratified sand and gravel that are frequently several km long and are somewhat like railroad embankments.

Answer 14

Esker

Question 15

A steep slope coinciding with the line of a fault

Answer 15

Fault scarp

Question 16

Associated with hogback ridges, triangular-shaped remnants of the bed between V-shaped notches, steeply sloping wedge-shaped landscape features created by differential erosion.

Answer 16

Flatirons

Question 17

A triangular face having a broad base and an apex pointing upward

Answer 17

Triangular facets

Question 18

German ‘sea of rock’, areas covered by a large angular blocks (formed in situ), traditionally believed to have been created by a freeze-thaw action

Answer 18

Felsenmeer or blockfield

Question 19

Major splits into limestone pavement, formed by widening, deepening, and eventual merging of solution features that developed along linear weakness in the rock.

Answer 19

Grike (Bogaz)

Question 20

Small closed depression on horizontal and gently inclined rock surfaces; similar to solution pits in carbonate rocks.

Answer 20

Gnamma (weathering pit or panhole)

Question 21

A mountaintop that has been modified by the action of ice during glaciation and frost weathering; also pyramidal peak.

Answer 21

Glacial horn

Question 22

A tall, thin spire of soft (sedimentary) rock topped by harder, more resistant stone that protects each column from erosion.

Answer 22

Hoodoo

Question 23

Large, perennial, conical, ice-cored mounds that are common in some low-lying permafrost areas dominated by fine-grained sediments, with the ice forming from injected water.

Answer 23

Hydrolaccoliths

Question 24

Large, freestanding, residual masses of rock and most common and most well known in granitic rocks.

Answer 24

Inselberg (tor/monadnock)

Question 25

A narrow piece of land connecting two larger areas across an expanse of water that otherwise separates them.

Answer 25

Isthmus

Question 26

Groups of residual, steep-sided conical-shaped hills produced by limestone solution.

Answer 26

Kegelkarst (cone karst or cockpit karst)

Question 27

An umbrella term which covers an elaborately diverse group of small-scale solutional features and sculpturing found on limestone and dolomite surfaces exposed at the ground surface or in caves.

Answer 27

Karren

Question 28

Large spitzkarren

Answer 28

Pinnacle karst

Question 29

Permafrost mounds formed by ice segregation within mineral soils that occur within the zone of discontinuous permafrost.

Answer 29

Lithalsas (stone rings)

Question 30

An embankment, natural or manmade, that confines flow during high-water periods.

Answer 30

Levee

Question 31

Occurs when a meandering river on alluvium eats down into the underlying bedrock.

Answer 31

Incised meander

Question 32

A prominent limestone hill in an area of tower karst.

Answer 32

Mogote

Question 33

An elongated cliff-base hollow cut out by abrasion, usually where breaking waves are armed with rock fragments.

Answer 33

Abrasion notch

Question 34

A point of land, usually high and often with a sheer drop, that extends out into a body of water.

Answer 34

Ness (headland/ promonotory/ cape)

Question 35

A horse-shoe shaped length of stream channel which is an almost closed meander loop.

Answer 35

Oxbow

Question 36

Forms just under a boulder, from which the rate of surface lowering may be evaluated

Answer 36

Pedestal

Question 37

A large karst depression that may sometimes be flooded with water, and which has been formed either by solution, or cavern collapse or for structural reasons.

Answer 37

Polje

Question 38

A sheet-like surface of rock fragments that remains after wind and water have removed the fine particles. It is covered with closely packed, interlocking angular or rounded rock fragments of pebble and cobble size.

Answer 38

Reg (dessert pavement/ gibber/ hamada)

Question 39

A long, narrow, often branching inlet formed by marine submergence of parts of a river valley that had previously been incised to a lower sea level.

Answer 39

Ria

Question 40

Accumulation of broken rock fragments that typically have a concave upwards form. The maximum inclination corresponds to the angle of repose of the mean debris size.

Answer 40

Scree or Talus

Question 41

An isolated upstanding steep-sided rock pillar, column or pinnacle rising from the shore, a shore platform, or the sea floor close to a cliffed coast

Answer 41

Stack or stump

Question 42

Cavernous weathering hollows produces in vertical or near-vertical rock faces.

Answer 42

Tafoni in calcareous sandstone

Question 43

A variety of limestone formed when carbonate minerals precipitate out of ambient temperature water.

Answer 43

Travertine or tufa

Question 44

A depression or larger hollow in limestone areas produced when several sinkholes or dolines coalesce.

Answer 44

Uvala

Question 45

Created when magma hardens within a vent on an active volcano. A distinctive upstanding landform produces when erosion removes the surrounding rock while the erosion-resistant plug remains.

Answer 45

Volcanic neck/pipe

Question 46

Corrosional notches at the cliff foot sometimes have protruding visors above them and plinths below them.

Answer 46

Visor

Question 47

Notch or abandoned former channel in resistant bedrock ridges that was formerly a water gap when there was insufficient stream power to complete the down cutting process.

Answer 47

Wind gap

Question 48

A tributary stream that is prevented from joining the main river because of the levees which flank the latter

Answer 48

Yazoo

Question 49

A streamlined hill carved from bedrock or any consolidated or semi-consolidated materials that resembles the hull of a boat.

Answer 49

Yardang/ Zeugen

Question 50

Isolated rocks between joints that result from downward erosion of less resistant layers.

Answer 50

Rock fins