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Geomorphological process at a glance:
Prof. P. K. Mani
BCKV, WB, India
Major geological landforms
Distribution of the principal folded belts formed since the Precambrian period (after Kummel
Landforms are theLandforms are the individual topographic features exposed on the Earth’s suindividual topographic features exposed on the Earth’s surface.rface.
LandformsLandforms vary in size and shapevary in size and shape and include features such as small creeks or sandand include features such as small creeks or sand
dunes, or large features such as the Mississippi River or Blue Ridge Mountains.dunes, or large features such as the Mississippi River or Blue Ridge Mountains.
Landforms develop over a range ofLandforms develop over a range of different time-scalesdifferent time-scales. Some landforms develop. Some landforms develop
rather quickly (over a few seconds, minutes, or hours), such as arather quickly (over a few seconds, minutes, or hours), such as a landslidelandslide, while, while
others may involve many millions of years to form, such as aothers may involve many millions of years to form, such as a mountain rangemountain range..
Landform development can be relatively simple and involve only a few processes, orLandform development can be relatively simple and involve only a few processes, or
very complex and involve a combination of multiple processes and agents.very complex and involve a combination of multiple processes and agents.
Landforms are dynamic features that are continually affected by a variety of earth-Landforms are dynamic features that are continually affected by a variety of earth-
surface processes includingsurface processes including weathering, erosion, and deposition.weathering, erosion, and deposition.
Earth scientists who study landforms provide decision makers with information toEarth scientists who study landforms provide decision makers with information to
make natural resource, cultural management, and infrastructure decisions, that affectmake natural resource, cultural management, and infrastructure decisions, that affect
humans and the environment.humans and the environment.
Table Rock Mountain is a
intrusion exposed by
millions of years of weathering
and erosion in South Carolina’s
TTopography refers to the elevation and relief of the Earth’s surface.refers to the elevation and relief of the Earth’s surface.
Landforms areare the topographic featuresthe topographic features on the Earth’s surface.on the Earth’s surface.
Geomorphology is the study of earth surface processes and landforms.is the study of earth surface processes and landforms.
The maps above represent the same area on Earth’s surface and they show three
different ways we can view landforms. The image on the far left is a clip from a
topographic elevation map, the image in the middle is an infrared aerial photo,
and the image on the right is the geologic interpretation of surface sediments
and geomorphology. This location is interesting because it contains elements of a
natural and human altered physical environment. The lake in the image, (coded
blue in the topographic and geology map, and black in the infrared aerial photo) was
formed by artificial damming a stream the flows through this landscape.
TopographyTopography is a term used to describe the Earth’s surface.is a term used to describe the Earth’s surface.
Topography includes a variety of different features, collectively referred to asTopography includes a variety of different features, collectively referred to as
Topography is measured by the differences inTopography is measured by the differences in elevation across the earth’sacross the earth’s
surface. Differences betweensurface. Differences between high and low elevationhigh and low elevation are referred to asare referred to as
changes inchanges in relief..
Scientist examine topography using a variety of different sources ranging fromScientist examine topography using a variety of different sources ranging from
paper topographic maps to digital elevation models developed using GIS.paper topographic maps to digital elevation models developed using GIS.
South Carolina’s elevation relief
ranges from 4,590 feet in the Blue
Ridge Region to 0 feet along the
Coastal Plain. The rivers dissect
the topography and drain
down-slope from headwaters in the
mountainous Blue Ridge and
Piedmont, into the alluvial valleys
of the Coastal Plain before draining
into the Atlantic Ocean.
South Carolina: 4 physiographic
provinces: Blue Ridge; Piedmont,
Sandhills and, Coastal Plain
Constructive and Destructive Processes
Constructive processes build landforms through tectonic and
Tectonic processes include movements at plate boundaries,movements at plate boundaries,
earthquakes, orogeny, deformation, and volcanic activity.earthquakes, orogeny, deformation, and volcanic activity.
Deposition is the accumulation or accretion of weathered and erodedis the accumulation or accretion of weathered and eroded
Destructive processes break down landforms through weathering,
erosion, and mass wasting.
Weathering is the disintegration of rocks by mechanical, chemical, andis the disintegration of rocks by mechanical, chemical, and
biological agents.biological agents.
Erosion is the removal and transportation of weathered material by water,is the removal and transportation of weathered material by water,
wind, ice, or gravity.wind, ice, or gravity.
Mass wasting is the rapid down-slope movement of materials by gravity.is the rapid down-slope movement of materials by gravity.
Other Agents and Processes that Affect Landform Development
Climate: temperature, precipitation, water cycle, atmospheric conditionstemperature, precipitation, water cycle, atmospheric conditions
Time: fast and slow rates of change: fast and slow rates of change
People: influences on natural resources and earth surface processes
Constructive processes are responsible for physically building or constructing
certain landforms. Constructive processes include tectonic and depositional
processes and their landforms.
Tectonic Landforms are created by massive earth movements due to
tectonic and volcanic activity, and include landforms such as: mountains,
rift valleys, volcanoes, and intrusive igneous landforms
Depositional Landforms are produced from the deposition of weathered
and eroded surface materials. Depositional landforms include features such
as: beaches, barrier islands, spits, deltas, flood plains, dunes, alluvial
fans, and glacial moraines.
Floodplain deposits at the confluence
of Mississippi and Arkansas Rivers.
The Stromboli Volcano erupting off the
coast of Sicily in the Mediterranean Sea.
Destructive processes create landforms through weathering and erosion of
surface materials facilitated by water, wind, ice, and gravity. Mass-wasting
events occur in areas where weathering and erosion is accelerated.
Weathering is the disintegration and decomposition of rock at or near the
Earth’s surface by mechanical, chemical, or biological weathering
Erosion is the removal and transportation of weathered or unweathered
materials by water, wind, ice, and gravity.
Mass-Wasting is a rapid period of weathering and erosion that removes and
transports materials very quickly and is often triggered by an environmental
stimuli. Mass wasting includes rock falls, landslides, debris and mud flows,
slumps, and creep.
Landforms formed by destructive processes include river and stream valleys,
waterfalls, glacial valleys, karst landscapes, coastal cliffs, and wave-
Reactivated ancient mega-landslide triggered by the March 28, 1999 Garhwal earthquake
at Dear in the Alaknanda River Valley. Barnard et al. (2001) dated the ancient landslide to
~8 ka using 10 Be terrestrial cosmogenic nuclides surface exposure dating,
Mohr–Coulomb’s law relates shear strength to cohesion, gravity, and friction.
When shear stress (a driving force) exceeds shear strength
(a resisting force), then slope failure occurs and the soil moves. In rock, weathering
(which may increase cohesion), the presence of joints and bedding planes (which
may reduce the angle of friction), pore water (which reduces effective normal stress
and increases cohesion), and vegetation (which increases the angle of friction and
may increase cohesion) affect shear strength.
The Mohr–Coulomb equation defines the shear stress that a body of soil on
a slope can withstand before it moves:
τs = shear strength of the soil, c = soil cohesion, σ = the normal stress (at right
angles to the slope), φ = the angle of internal friction or shearing resistance.
The angle φ is not necessarily the slope angle but is the angle of internal friction
within the slope mass and represents the angle of contact between the particles making
up the soil or unconsolidated mass and the underlying surface.
The Mohr–Coulomb equation can be used to define the shear strength of a unit of
rock resting on a failure plane and the susceptibility of that material to
landsliding, providing the effects of fractures and joints are included. Whenever
the stress applied to a soil or rock body is greater than the shear strength, the
material will fail and move downslope
Genetic Landform Classification
The genetic landform classification system groups landforms by theThe genetic landform classification system groups landforms by the
dominant set of geomorphic processes responsible for their formation.dominant set of geomorphic processes responsible for their formation.
This includes the following processes and associated landforms:This includes the following processes and associated landforms:
Extrusive Igneous Landforms
Intrusive Igneous Landforms
Ocean Floor Topography
Within each of these genetic classifications, the resulting landforms are a
product of either constructive and destructive processes or a
combination of both. Landforms are also influenced by other agents orLandforms are also influenced by other agents or
processes includingprocesses including time, climate, and human activitytime, climate, and human activity..
Mountains: Orogenesis and
Domes and Basins
Horst and Graben Rift Valleys
Major Mountain Ranges:
The Valley of Kaveri river near Hogenekal,
Dharmapuri dist, TN in the form of gorge
Orogenesis is the thickening of theOrogenesis is the thickening of the continental crustcontinental crust and theand the building of
mountains over millions of years and it translates from Greek as “birth ofover millions of years and it translates from Greek as “birth of
mountains”, (mountains”, (orosoros is the Greek word for mountain).is the Greek word for mountain).
Orogeny encompasses all aspects of mountain formation including plate tectonicsOrogeny encompasses all aspects of mountain formation including plate tectonics
terrane accretion, regional metamorphism, thrusting, folding, faulting, and igneousterrane accretion, regional metamorphism, thrusting, folding, faulting, and igneous
Orogenesis is primarily covered in the plate tectonics section of the earth scienceOrogenesis is primarily covered in the plate tectonics section of the earth science
education materials, but it is important to review for the landform section becauseeducation materials, but it is important to review for the landform section because
it includes deformation processes responsible for mountain building.it includes deformation processes responsible for mountain building.
South Carolina’s Blue Ridge Mountains and
Inner Piedmont Region were formed by multiple
orogenic events when rocks forming South
Carolina were uplifted, metamorphosed, folded,
faulted, and thrusted. More information on the
Blue ridge mountains is included on the section
for the Appalachian Mountain Range.
Major Mountain Ranges of the World
Antarctica: Antarctic Peninsula, Transantarctic Mountains
Africa: Atlas, Eastern African Highlands, Ethiopian Highlands
Asian: Himalayas, Taurus, Elburz, Japanese Mountains
Australia: MacDonnell Mountains
Europe: Pyrenees, Alps, Carpathians, Apennines, Urals, Balkan Mountains
North American: Appalachians, Sierra Nevada, Rocky Mountains, Laurentides
South American: Andes, Brazilian Highlands
European AlpsEuropean Alps
Himalaya orogeny began 45-54 million years ago from the collision between theHimalaya orogeny began 45-54 million years ago from the collision between the India
and Eurasian Plates and is still active today.and is still active today.
When two continental plates collide, theWhen two continental plates collide, the Earth’s crust at the plate boundaries is folded,
faulted, overthrusted, uplifted forming an extensive continental mountain range.forming an extensive continental mountain range.
Today, the Himalayas separate theToday, the Himalayas separate the Indian sub-continent from thefrom the Tibetan Plateau andand
they are recognized as the tallest above sea level mountains on Earth. The Himalayasthey are recognized as the tallest above sea level mountains on Earth. The Himalayas
contain 10 of the tallest mountain peaks on Earth >8,000 meters , including Mountcontain 10 of the tallest mountain peaks on Earth >8,000 meters , including Mount
Everest with a peak ofEverest with a peak of 8850 meters (29,035 ft). In addition, the Himalayas include(29,035 ft). In addition, the Himalayas include
three major individual mountain ranges, thethree major individual mountain ranges, the Karakoram, Hindu Kush, and, and Toba Kakar..
Shallow, intermediate, and deep earthquakes are associated with this zone, predictionare associated with this zone, prediction
of several major earthquakes will occur in the region.of several major earthquakes will occur in the region.
The name Himalaya is from Sanskirt,
and it means “the abode of snow”.Continental – Continental Plate Collision
Intercontinental collision orogen
formed where two continental plates
collide. An example is the Himalaya.
Volcanic Landforms: Extrusive Igneous
Calderas are bowl-shaped
formed by volcanic
Stratovolcano 354 m / 1,161
ft. Indian Ocean
Barren Island, the only historically
active volcano along a volcanic
arc connecting Sumatra and
Myanmar . The small 3-km-wide
island contains a 1.6-km-wide crater
partially filled by a cinder cone that
has been the source of eruptions
since the first was recorded in 1787.
Lava flows reached the coast during
several recent eruptions.
Structure of a Typical strato-volcano
B) Chachahén Volcano, Mendoza Province, Argentina, a volcano with strong effect of
erosion but no denudation
C) Cardiel Lake, Santa Cruz Province, Argentina, a volcanic area under strong effect of
denudation, exposing subvolcanic rock body
A) Villarrica Volcano,
Chile, a volcano without
efects of erosion and
Volcanic Landforms: Intrusive Igneous
Table Rock in South Carolina is an
example of a monadnock landform
Half Dome is a granitic igneous intrusion that forms an
impressive mountain peak(greater Sierra Nevada
Batholith in Yosemite National Park
Enormous granite batholiths often underlie and support the most elevated sections of
continental margin orogens, as in the Andes.
Intrusions form where molten and mobile igneous rocks cool and solidify without
breaching the ground surface to form a volcano.
Phacoliths. (a) Occurrence in anticlinal crests and synclinal troughs. (b) Corndon Hill,
near Montgomery in Wales, an eroded phacolith
• Subduction of Mediterranean crust under Italy, Greece,Subduction of Mediterranean crust under Italy, Greece,
and Turkey continues to cause volcanism and seismicityand Turkey continues to cause volcanism and seismicity
• In 1999 an earthquake killed 17,000 people in TurkeyIn 1999 an earthquake killed 17,000 people in Turkey
Italy and GreeceItaly and Greece
Mount VesuviusMount Vesuvius, Italy, has erupted, Italy, has erupted
80 times since it destroyed Pompeii80 times since it destroyed Pompeii
in A.D. 79in A.D. 79
Mount EtnaMount Etna, Sicily, is, Sicily, is
Earth’s most active volcanoEarth’s most active volcano
River Systems and Fluvial Landforms
River Systems and Fluvial Landforms
Longitudinal Profile and Watersheds
Lakes and Dams
Alluvial Fans Satellite scenes showing braided
channel segments of Gandak
(left) and Son (right) rivers
Arrows show the direction of flow
Narmada floodplain inside the high
banks of the large flood channel in
alluvium. Note mudcracks in the clay.
An anabranch is a section of
a river or stream that diverts from
the main channel or stem of
the watercourse and rejoins the
main stem downstream.
Baghmati river system from north Bihar
The enormous Brahmaputra-
Jamuna River in Asia is a classic
example of a braided river.
Entrenched meanders occur when a river channel cuts down into the flood plain or bedrockEntrenched meanders occur when a river channel cuts down into the flood plain or bedrock
and the channel is trapped within a single course and it can not migrate laterally but erodesand the channel is trapped within a single course and it can not migrate laterally but erodes
the landscape by down-cutting. This process will often leave behind numerous terraces ofthe landscape by down-cutting. This process will often leave behind numerous terraces of
varying width and expose multiple layers of rock.varying width and expose multiple layers of rock.
TheThe Colorado RiverColorado River flowing through theflowing through the Grand Canyon in ArizonaGrand Canyon in Arizona, provides a classic, provides a classic
example of entrenched meanders. Down cutting began as the Colorado Plateau wasexample of entrenched meanders. Down cutting began as the Colorado Plateau was
uplifted about 5 million years ago and the river responded by eroding into the valley anduplifted about 5 million years ago and the river responded by eroding into the valley and
has maintained roughly the same course ever since.has maintained roughly the same course ever since.
Below are the entrenched meanders of the Colorado River
and to the right is the first geologic interpretation of the
numerous geologic units exposed by the down cutting river.
Anabranching river patterns contain multiple channels that weave a mosaic through semi-Anabranching river patterns contain multiple channels that weave a mosaic through semi-
permanent alluvial vegetated islands. The islands are often the same height as the floodpermanent alluvial vegetated islands. The islands are often the same height as the flood
plain and were likely isolated from the flood plain by meander bend cutoffs, channelplain and were likely isolated from the flood plain by meander bend cutoffs, channel
avulsions (abandonment of an entire channel segment), or mid-channel deposition andavulsions (abandonment of an entire channel segment), or mid-channel deposition and
subsequent vegetation.subsequent vegetation.
Anabranching rivers often occur in alternating combination with other river forms, such asAnabranching rivers often occur in alternating combination with other river forms, such as
meandering, braided, or straight rivers.meandering, braided, or straight rivers.
Anabranching rivers provide added habitat complexity and support rich biodiversity.Anabranching rivers provide added habitat complexity and support rich biodiversity.
This section of the Little Pee Dee River in South
Carolina represents an anabranching river, most likely
formed by channel avulsion (channel abandonment)
and reoccupation of both the old and new channel.
Upstream and downstream from this segment the river
is mainly a single meandering channel with a wide
alluvial flood plain and multiple meander bend cutoffs.
An alluvial fan deposited by a hill
stream on the way to Amarnath, J & K
and point bars
Alluvial fans in a the Indus Valley
emerging from in the Nubra Valley
The Marble Canyon on the Narmada River
downstream of Dhuandhar Falls at
Bedhaghat near Jabalpur. The gorge is
cut in nearly vertically dipping dolomite
Rivers are natural streams of water that flow from higher to lower
elevations across the land surface. Their continued existence relies upon a
supply of water from overland flow, throughflow, interflow, baseflow, and
precipitation falling directly into the river. Channelized rivers are streams
structurally engineered to control floods, improve drainage, maintain
navigation,and so on. In some lowland catchments of Europe, more than 95
per cent of river channels have been altered by channelization.
Water flowing in an open channel (open channel flow) is subject to
gravitational and frictional forces. Gravity impels the water downslope,
while friction from within the water body (viscosity) and between the flowing
water and the channel surface resists movement. Viscosity arises through
cohesion and collisions between molecules (molecular or dynamic
viscosity) and the interchange of water adjacent to zones of flow within
eddies (eddy viscosity).
Reynolds number = is a
dimensionless number that
includes the effects of the flow
characteristics, velocity, and
depth, and the fluid density and
mean flow velocity (v),
kinematic viscosity, υ =
molecular viscosity ( ),μ
fluid density (ρ)
Re = 500 Laminar
Re = 2000,Turbulent
V = flow velocity, d = depth of flow
√ gd =velocity of the gravity waves
F <1 flow, sub critical
F = 1 flow, critical
F > 1 flow, supercritical /shooting
Meander loop: A single loop of a meandering
Cutbank. The bank that experiences erosion.
Point bar. The deposits that accumulate opposite
CutbanksCutbanks form along the outerform along the outer convex margin of meander bendsconvex margin of meander bends. Cutbanks , unlike most. Cutbanks , unlike most
floodplain landforms are actuallyfloodplain landforms are actually erosional features formed by the lateral movement of theformed by the lateral movement of the
channel across the flood plain. Flood plain sediments are eroded from the cutbank andchannel across the flood plain. Flood plain sediments are eroded from the cutbank and
deposited on pointbar surfaces.deposited on pointbar surfaces.
PointbarsPointbars are concave,are concave, depositional landformsdepositional landforms that form opposite of the eroding cutbanks,that form opposite of the eroding cutbanks,
and they develop in concert with the laterally migrating river channel.and they develop in concert with the laterally migrating river channel.
Natural leveesNatural levees are depositional landforms formed from the vertical accumulation ofare depositional landforms formed from the vertical accumulation of
sediments deposited during flood events. Natural levees form topographically higher surfacessediments deposited during flood events. Natural levees form topographically higher surfaces
adjacent to the river channel.adjacent to the river channel.
Crevasse channels and splaysand splays are breaches in the natural levee that result in the fan-are breaches in the natural levee that result in the fan-
shaped deposition of flood deposits, beyond or over levee deposits.shaped deposition of flood deposits, beyond or over levee deposits.
Oxbow lakes oror infilled channels form when aform when a meander bend is cut off from the main riverfrom the main river
and abandoned in the floodplain.and abandoned in the floodplain.
Backswamps are typically low-lying areas of the floodplain beyond the natural leveeare typically low-lying areas of the floodplain beyond the natural levee
deposits. Backswamps contain the finest-textured flood plain deposits and may even developdeposits. Backswamps contain the finest-textured flood plain deposits and may even develop
organic-rich soils from the forest litter.organic-rich soils from the forest litter.
Yazoo tributaries are stream networks that enter the floodplain but the natural leveeare stream networks that enter the floodplain but the natural levee
prevents the stream from flowing into the river. As a resultprevents the stream from flowing into the river. As a result the yazoo tributary flows parallel
to the mainstem river before reaching a breach in the levee or occupying the course of anin the levee or occupying the course of an
Gullys are formed by hillslope erosion.
Rainwater runoff draining over the surface of a hillslope generates erosive
overland flows that remove weathered rocks and soil.
When multiple gullys form they produce a disconnected network of
headwater channels that dissect the hillslope and increase soil erosion.
Gullys primarily form on disturbed hillslopes where forest and vegetation
have been cleared.
The forest was cleared from this
hill slope and corn was planted
on the bare soil. Following the
first few rain events, gullys
began to form as a result of soil
erosion. The gullys only carry
water during rainfall events.
Karst is a term used to describe landscapes that are formed by chemical
weathering process controlled by groundwater activity. Karst landscapes are
predominantly composed of limestone rock that contains > 70 percent calcium
Onondaga Cave in Missouri is a karst
landform formed by chemical
solution in carbonate limestone
rocks. Features within Onondaga
Cave include stalagmites, stalactites,
dripstones and active flowstone
Missouri known as the “Cave State”
Stalactites are deposits that grow from the
ceiling downward and stalagmites are deposits
that grow from the ground up (New Mexico)
Karst springs are locations whereKarst springs are locations where groundwater emerges from the limestonegroundwater emerges from the limestone
and flows across the surfaceand flows across the surface forming a stream or contained pool.forming a stream or contained pool.
The flow of Karst springs is generally dependant on the weather and climate.The flow of Karst springs is generally dependant on the weather and climate.
Some are more permanent than others, while others only flow following rainfall orSome are more permanent than others, while others only flow following rainfall or
snowmelt events. Springs that are connected to aquifers flow year-round andsnowmelt events. Springs that are connected to aquifers flow year-round and
support rich aquatic biodiversity.support rich aquatic biodiversity.
Karst springs generally do not support good water quality, and thus are not safe forKarst springs generally do not support good water quality, and thus are not safe for
drinking without filtering the water first; however, the springs often provide fundrinking without filtering the water first; however, the springs often provide fun
recreational opportunities and can be a popular place for swimming andrecreational opportunities and can be a popular place for swimming and
Karst springs provide cool, clear, water that is inviting for
people to swim and snorkelin. Bakreswar spring, WB; and
Barton Springs, a karst spring in the Texas Hill Country.
Loess FormationsLoess Formations
Carolina BaysCarolina Bays
Aeolian landforms are formed by the
deposition of wind blown sediments.
The sediments are generally sourced from
deserts, glacial deposits, rivers or coastal
shorelines. Aeolian sediments are often
composed of well-rounded, sand-to silt-
sized particles, that are weathered by wind
abrasion during transport. Sediments are
deposited when the velocity of the wind
falls and there is not enough energy
available to entrain and transport the
uz = wind speed at height z,
z = height above the ground,
Κ = Kármán constant (≈0.4)
z0 = roughness length,
u∗ = shear or friction,
τ0 = shear force per unit area
A Yardang is an elongate ridge or remnant
rock feature sculpted by abrasive wind erosion
Large barchan sand dune at the
Shyok-Nubra confluence in Ladakh
Etched and grooved limestone formed
due to aeolian sand blasting on a
hamada surface near Jaisalmer
Loess deposits are regionally extensive accumulations of
windblown silt resulting from thousands of dust
During the dust storms, silt is entrained, transported,
and deposited as loess. Loess deposits are generally
sourced from either glacial or desert terranes, and silt
may be transported for 100's of miles before being
Loess deposits are generally coarsest and thickest close to
their source, and they decrease in thickness and grain size
with increasing distance from their source.
Loess is not stratified, meaning it lacks distinctive
layers. Instead they are massive accumulations of silt.
Loess deposits range from 30 to >100 m thick, and they
provide very fertile soils for agriculture and farmland.
The most extensive loess deposit occurs in western and
northern China, and it contains sediments that were blown
from the deserts of Central Asia.
This loess and sandstone contact
is from a quarry near Vicksburg,
Mississippi where both deposits
are being mined. This loess was
sourced from glacial till and blown
down the Mississippi River Valley.
The person in the picture provides
a context for the thickness of the
Carolina BaysCarolina Bays
Carolina Bays are oval or elliptical, depressional wetland features enclosed by a low
sandy ridge. The depth of Carolina Bays varies depending on their size and land use history,. The depth of Carolina Bays varies depending on their size and land use history,
most average about 5-15 feet deep; however, some have been measured with depths greatermost average about 5-15 feet deep; however, some have been measured with depths greater
than 30 feet . Sand rims enclosing the Carolina Bays also vary in size, range from 5-15 feet.than 30 feet . Sand rims enclosing the Carolina Bays also vary in size, range from 5-15 feet.
The origin of Carolina Bays: Most Geologists agree that they areThe origin of Carolina Bays: Most Geologists agree that they are eolian landformeolian landforms. Carolinas. Carolina
Bays were formedBays were formed 100,000-30,000 years ago100,000-30,000 years ago, during the Quaternary and occur through the, during the Quaternary and occur through the
coastal plain of Georgia, South Carolina, North Carolina, Virginia, and Maryland.coastal plain of Georgia, South Carolina, North Carolina, Virginia, and Maryland.
Carolina Bays occur in varying stages of flooding dependant on their land-use history, rainfall,Carolina Bays occur in varying stages of flooding dependant on their land-use history, rainfall,
and connection to ground water. Carolina Bays can be dry, temporarily flooded, or support aand connection to ground water. Carolina Bays can be dry, temporarily flooded, or support a
permanent lake.permanent lake. Most Carolina Bays have their longest axis oriented from northwest to
southeast, although there are a few oriented in other directions. The sand
rims are largest along the southeastern edge, but in some cases may be
completely lacking. Many Carolina Bays have been drained to support
agriculture. Undisturbed Carolina Bays contain unique assemblages of
wetland plants and aquatic organisms. This aerial image contains 4
Carolina Bays, three of which support agriculture and one, Woods Bay,.
A Carolina Bay extensively drilled in South Carolina revealed that its
formation was the result of dissolution of a carbonate coral head
and subsequent subsidence of the overlying materials creating the
depression in land surface. Within the center of the bay there was no
carbonate material detected. Near the rim of the bay, extremely
weathered remnants of coral were penetrated and represented the
lateral limits of the coral head.
Littoral ZoneLittoral Zone
Barrier IslandsBarrier Islands
Beach RidgesBeach Ridges
Coastal CliffsCoastal Cliffs
Marine TerracesMarine Terraces
Wave-Cut ScarpsWave-Cut Scarps
Coastal landforms include a diverse array of shoreline
and near-shoreline features, as well as some coastal
plain landforms far removed from the modern ocean
by long term sea-level changes. This section will
explore both constructive and destructive landforms
formed by current coastal processes, as well as
marine related landforms that were formed during
periods of higher sea level.
The Ganges Delta
(Sunderban Delta or
the Bengal Delta)
Coastal and off shore morphology along the Indian subcontinent. GKC= Gulf of kachchh, GKB= Gulf of
Khambhat, GM= Gulf of Mannar, PS =Palk Strait. The boundary of Indus and Bengal Fan is approximate.
The Bengal fan, with an area of ~ 3 million km2
is the largest deep sea fan in the world. The area of Indus
Fan is ~ 1.1 m Km2
The zone in the ocean that experiences the effects of the tides.
It is the region of the sea between high and low tides.
t is sometimes called the intertidal zone.
The LITTORAL zone
This wave-cut scarp and platform near Brigden, South Wales was
formed by the erosive action of the sea’s waves.
Sea arches form by erosive
wave refraction on opposite
sides of a headland
Sea cliffs are erosional landforms formed by
the undercutting action of the sea against the
coastline San Mateo County, California
Wave-cut platform in khondalites 10 km
southwest of harbor channel in
Visakhapatnam on the east coast
Ice sheets and Alpine Glaciers
Ice Field and Ice Caps
Tidal Glaciers and Icebergs
Glacial U-shaped Valleys
Cirques and Cirque Glaciers
Arêtes, Horns, Cols
Lateral and Medial Moraines
End and Terminal Moraines
Glaciers are large masses of moving ice. Because glaciers
are “frozen” they are part of the Earth’s cryosphere, which
accounts for 77 percent of all Earth’s freshwater.
Glaciers are very sensitive to the slightest temperature
changes. Over Earth’s geologic history the spatial extent
and size of glaciers has expanded and shrunk numerous
times. As a result, glacial landforms can be found in
locations that currently have no active glaciers or glaciation
processes. Presently, glacial landforms occur in two distinct
geographic regions, high latitude polar environments and
high altitude mountain environments. In this section we will
explore glacial landforms from their present context and
from a historic look into the past.
Alpine Valley Glacier in Alaska.
ρi = ice density, h = ice thickness, β = ice-surface slope.
Hydrostatic pressure depends on the weight of the
overlying ice and is spread equally in all directions.
Shear stress depends upon the weight of the ice
and the slope of the ice surface
shear stress, τ0
Glaciers flow because ice deforms as a result of basal shear stress.
Driving and resisting stresses operating on a block of ice on an inclined slope.
Glacier flow is a combination of the deformation of the ice and the bed, and sliding of ice over its
bed. Glacier velocity therefore equals deformation plus basal sliding.
Glaciers flow because permanent deformation occurs as a result of strain in response to
stress. Strain may include deformation of the ice or the sediments at the ice-bed interface,
or sliding at the ice-bed interface. Resistance to strain depends on ice temperature, crystal
structure, bed roughness, debris content, water pressure and other factors.
Glen’s power flow law gives
the shear strain and applied
stress in ice:
ε is the strain rate, A and n
are constants, and τ is the
basal shear stress. The
constant n = 3
We have many glaciers in our country
moving down the slopes and valleys in
Himalayas. Higher reaches of Uttaranchal,
H. P. and J & K, are places to see some of
them. River Bhagirathi is basically fed by melt
waters from under the snout (Gaumukh) of
the Gangotri Glacier. In fact, Alkapuri
glacier feeds waters to Alakananda river.
Some glacial erosional and
depositional forms ( Spencer, 1962)
Karakoram range in the Himalaya
Major Landforms of India
1.Mountains – The Himalayan mountain range is a major landform in India. It
borders on the Northern part of India
Mount Everest is located in the Himalyan range.
The Aravalli range – This is situated in the western part of India and runs
about 800 km from the northeast to the south west, traversing Rajasthan.
2. Volcanoes – These are found in the Andaman Islands such as Barren
Islands, Baratang, Narcondam and Deccan Traps. The volcanoes are
dormant and active.
3. Glaciers – These are found in Jammu and Kashmir, Himachal Pradesh,
Uttarkhand and Sikkim. The Siachen glacier happens to be the largest
glacier outside of the polar region. It is the largest in the Himalayas -
Karakoram. It is in Jammu and Kashmir.
4. Valleys – The Damodar Valley in Jharkahand and West Bengal.
The Araku valley in Vishakapatnam in Andhra Pradesh
The Kashmir valley is very beautiful.
5. Deserts – The Thar Desert is the Great Indian Desert and lies in Rajasthan.
6. Islands – The Andaman Islands are very famous.
They are in the Bay of Bengal. The Nicobar islands
are in the eastern Indian Ocean.
7. Waterfalls – Famous water falls are Chitrakot which is 100 ft, Chattisgarh.
•Then you have the Kuntala Falls in Andhra Pradesh.
•The Dudhsagar Falls is 1,017 feet. Situated in Goa.
•The Jog Falls in Karnatka
8. Beaches – Goa, one comes across several beaches. Here, the Arambol
beach is famous as well as the Anjuna Beach and many more,
•The Vizag beach is famous in Andhra Pradesh.
• In Madras, the Marina beach and the Adyar beach are very popular
9. Plains – the Indo-Gangetic plain is very famous. It is extremely fertile and is
in the northern part of India. The Eastern coastal and Western coastal are other
regions which are part of the plains in India
India's geological features can be divided based on their formation in
different periods of the Geological Time Scale. Accordingly, India's
geographical land can be classified into
and into those that originated in
Pleistocene, Tertiary, and Pre-Cambrian Period
The Deccan Trap covers almost all of Maharashtra, a part of Gujarat,
Karnataka, MP and AP marginally.
Geologists believe that the Deccan Trap was formed as result of sub-aerial
volcanic activity associated with continental divergence in this part of the earth
during the Mesozoic era.
The rocks found in this region are generally of igneous type.
The Gondwana and Vindhyan include within its fold parts of Madhya
Pradesh, Chhattisgarh, Orissa, Andhra Pradesh, Maharashtra, Jammu and
Kashmir, Punjab, Himachal Pradesh, Rajasthan and Uttaranchal
The Gondwana Supergroup forms a unique sequence of fluviatile rocks
deposited in Permo-Carboniferous & Mesozoic times.
Damodar and Sone river valley and Rajmahal hills in the eastern India
are repositories of the Gondwana rocks.
The vast plateau mountains to the north of Narmada River in Madhya
Pradesh and the adjoining areas of Malwa Plateau and Gangetic Plains form
the Vindhyan cover. Here, the Deccan Trap and the alluvium conceal the
rocks. The lower Vindhyans (Semri Group) are dominantly limestones,
whereas the upper parts of the succession are mostly sandstones
Formations, which are of recent or Pleistocene origin, are found over
relatively large area of India. Parts of the geographical area of the states of
Uttar Pradesh, Rajasthan, Punjab, Gujarat, Madhya Pradesh, Tamil Nadu,
Andhra Pradesh, Orissa, Kerala, Karnataka, Maharashtra, Assam, Bihar and
Haryana come under this geological category