Earth Science Topic

1. MOUNTAINS
They are types of landform, which are
characterized by high elevation. They are
steeply above their surrounding to a narrow
summit on top.
Compared to other landform, like hills
they are much higher, taller and steeper.
They are higher as much as 8000 meters,
Highest Mountain is the Mountain
Everest – 8,850 meters tall.

2. • They are landform that strecthes above
the surrounding land in a limited area,
usually in the form of a peak.
• These forces locally rises in the surface of
the earth’s crust by over 10,000 ft.
• It erode slowly through the action of
rivers, weather conditions, and glaciers.
• High elevations on mountains are colder
than at sea level, which affect the
ecosystem of mountains with different
elevation.
• Highest Mountain – Mount Everest –
Himalayas. Whose summit – 8,849,868 m.
Above sea level.

3. • Pic of Mt Everest

4. Mountains Range Country Feet
1. Everst Himalayas Nepal/Tibet 29,035
2. K2 (Mount Godwin
Austen)
Karakoram Pakistan/China 28,250
3. Kangchenhjunga Himalayas Indian/ Nepal 28,169
4. Lhotse Himalayas Nepal/Tibet 27,940
5. Makalu Himalayas Nepal/Tibet 27,766
6. Cho Oyu Himalayas Nepal/Tibet 26,906
7. Dhaulagiri Himalayas Nepal 26,,795
8. Manaslu Himalayas Nepal 26,781
9. Nanga Parbat Himalayas Pakistan 26,660
10. Annapurna Himalayas Nepal 26,545

5. Varying climatic condition can be
observed on the mountains due to their
elevations or height. The conditions at
the base of a very tall mountain differ
from the topmost area.
The peak is colder and may eveb
snow –covered .
There are less oxygen and less
protection from the sun’s ray on top.

6. TYPES OF MOUNTAINS
BASED ON FORMATION
1. volcanic
2. dome
3. erosional
4. fault-block
5. folded

7. VOLCANIC MOUNTAINS
Also known as volcanoes.
They are formed due to volcanic
eruptions. Due to very high temperature
inside the earth, the hot molten material
called magma finds its way out on the earth’s
surface.
Magma becomes lava once it goes out of
the earth’s surface. When this lava erupts
and piles up on the surface of the earth, it
cools and solidifies to form a volcanic
mountain.
Ignreous rocks are formed in this
mountain. Examples are the Mount Fuji in
Japan and Mount Erne in Europe.

8. Mount Fuji

9. DOME MOUNTAIN
It is built from the hot magman that
rises from the mantle and uplifts the
overlying sedimentary layer of the earth’s
crust. Magma is not erupted in the process
but cools down and hardens, forming the
core of the mountain.
It is called dome mountain because its
appearnce resembles a dome shape.
Examples are the Navajo mountain in
Utah and Adirondack Mountains in New
York.

10. Pic of dome mt.

11. EROSIONAL MOUNTAINS
Water and wind may wear
foundations of lands. These lands may be
carried away.
Some lands may resist waer and wind
and may remain in place.
These materials may resist erosion and
will lead ton the formation of erosional
mountains. Examples are the Pike’s Peak
in Colorado, which is a large mass of
granite that has resisted erosion for many
years.

12. Pic of erosional mt.

13. FAULT-BLOCK MOUNTAINS
They are formed when blocks of rock
materials slide along faults in the earth’s
crust.
Fault-block mountains may be of two
types:
1. lifted – lifted has two steep sides
2. tilted – has one steep side and a gentle
sloping side. Example are Sierra Nevada
Mt. And the Teton Range in North America.

14. Fault-block mt.

15. FOLD MOUNTAINS
These are the most common type of
mountains. They are formed due to collision of
two plates, pushing against each other.
Pushing against each other causes intense
pressure causing folding of the earth’s crust.
The fold that descends on both sides is
called anticline.
The fold that ascends from a common low
point is called syncline. Examples are the
Himalayas in Asia, Rocky Mountains in North
America and the Alps in Europe.

16. Pic of Fold Mt.

17. Weathering
The surface of the earth is always
changing due to the natural process –
Weathering. It is a process which
changes the physical and chemical
properties of rocks and soil on the
earth’s surface.
It is also the first step to soil
formation.

18. breaking down of rocks, soil and minerals
through theearth’s atmosphere , biota and
water.

19. WEATHERING, SOIL AND MASS
WASTING
Two types of Weathering:
1. Physical or Mechanical Weathering
2. Chemical Weathering
Physical /mechanicalWeathering – occurs
when physical forces break rocks or soil
into smaller pieces without changing the
rock’s composition, which is cause by:
1. Frost wedging or water or ice – the
mechanical break-up of rock is due to the
expansions of freezing water in cracks.

20. 2. Pressure (Stress) Release or heat – also
known as unloading which occurs when
overlying materials that cause stress to
the underlying rocks are removed by
erosion.
3. Salt Crystal Growth (Salt Crystallization) –
the disintegration of rocks which is caused
by salt solution that seep into cracks and
joint in the rocks. The water component of
the salt solution evaporates leaving salt
crystals behind. When salt crystals are
heated up, it expands exerting pressure
on the rock which causes its breakdown.

21. 4. Water (hydraulic )action – The
disintegration of rocks is caused by water
from powerful waves that moves rapidly
into cracks in the rocks.
5. Thermal (Insolation) Stress – Rock
expands when heated and contracts when
cools. The outer layers of the rocks peel off
in thin sheets because of the temperature
changes which cause expansion and
contraction of rock. It is an important
mechanism in desserts, where there is a
large temperature range, hot in the day
and cold at night.

22. Chemical Weathering –is a weathering
which causes change in the composition of
rock due to different chemical reaction,
like:
1. Cabonation – it occurs when water (rain)
combines with carbon dioxide or an
organic acid to form a weak cabonic acid.
This acid reacts with calcium carbonate
(limestones) present in the rock and forms
calcium bicarbonates. Decrease
temperature can speed up the chemical
reaction because cold water holds more
dissolved carbon dioxide gas. Therefore,
carbonation is a significant feature of
glacial weathering.

23. 2. Hydrolysis – refers to the reaction
between water ans silicate and carbon
minerals present in rock.
3. Oxidation – it involves the reaction
between oxygen (air or water) and
metal (iron) present in rock.

24. BIOLOGICAL WEATHERING
Living organisms may contribute to
mechanical or chemical weathering.
Plants, animals and human can cause
physical breakdown of rocks. The
attachment if lichen and mosses to the
rock surface can cause physical
breakdown of rocks. Plant roots can
cause physical breakdown weathering.

25. SOIL
It is the product of weathering of rocks.,
which is vital for the existence of life forms. It
supports the growth of plants, which in turn
supplies nutrients to other organisms in the
ecosystem.
PEDOGENESIS – process of soil development,
influenced by 4 interrelated factors.
1. Climate – greatest effect on soil formation.
Temperature and moisture are the two
imortant climate variables that have significant
influence on soil formation.

26. 2. Living Organisms – plays a
significant role in various processes
involved in pedogenesis suh as;
1. Organic matter accumulation
2. Profile mixing
3. Biogeochemicak nutrient cycling
Decayed living matter adds humus or
nutrients to the soil.
Plants and animals participate in the
biogeochemical cycle especially the
carbon and nitrogen Cycle.

27. 3. Parent material – refers to the
unconsolidated rock and mineral
materials from which the soil develops.
The type of parent material determines
which minerals are poresent in the soil.
In residual soil the parent material is
the bedrock while in the transported
soil, the oparent material has been
carried from elsewhere and deposited.

28. 4. Topography – refers to the physical
features of an area, which modifies the
development of soil because of its effect
on microclimate and drainage.
Topography – influence the runoff of water
which can hinder soil formation because
of constant erosion.
Microclimate – refers to the climate of the
specific place which can affect the soil
formation due to the relative warmth and
moisture that influence the rate and
degree of weathering.

29. CHARACTERISTICS OF SOIL
1. Texture – refers to the size distribution of the
mineral particles found in soil. Particles are
normally grouped into three:
1.1 sand
1.2 silt
1.3 clay
Sandy Soil – has the biggest particles which is good
for aeration and drainage of the soil. It is an
advantage for plants, it allows the water to drain
easily which prevent root to rot problems. It is
granular and consists of rocks and minerals that
are very small. It is formed by the disintegration
and weathering of rocks such as limestone,
granite, quarts and shale.

30. It is easier to cultivate because of the
organic material, moisture and
nutrients. During spring season they
warm very fast.
Silty Soil – it one of the most fertile soil. It
is composed of minerals like quarts,
and fine organic particles, has more
nutrients than sandy soil. It is granular
like sandy soil, but it offer better
drainage. Hold more moisture which
makes it much easier to work with.

31. Clay Soil – is rich in minerals content
and very fine grain materials with very
less air space which is responsible for
its low drainage. It is heavy when wet,
making it difficult to cultivate.
It can be formed into sedimentary rocks
deposits after weathered, eroded and
transported.

32. EROSION
Removal of soil sediment, regolith and
rock fragments from the landscape.
Three processes involve in erosion:
1. Detachment – revomal of particles from
surrounding materials due to physical,
chemical and biological weathering.
Different mechanism for the detachment
are;
1.1 Plucking – occurs when ice freezes
onto the surface and cracks which causes
fragmentation of the rocks.

33. 2. Cavitation is caused by moving water with
high velocity like high waterfalls.
3. Abrasion – is due to the excavation of
surface particle by materials carried by the
erosion agent.
2. Entrainment – process of particle lifting by the
agent of erosion. The particles cohesive
bondsweakened by weathering or forces
created by erosion.

34. • 3.Transport – once a particle is entrained,
transport can already occur through various
mechanisms such as suspension, saltation,
traction and solution.
A. Suspention- is where the particles are carried
by the medium without touching the surface
of thier origin.
B. Saltation- is where the particle moves from
the surface to the medium in quick continuous
repeated cycles.

35. C. Traction- which ocurs in all erosional mediums
in characterized by the movement of particles
by rolling, sliding, and shuffling along the
aroded surface.
D. Solutions- is a transport mechanism that
occurs only in aqueous environments.
• Deposition the process which ends erosion is
known as deposition which occurs when the
transported particles fall out of the
transporting medium and settle on a surface.

36. Mass Movement or mass wasting is the
geomorphic process by whitch soil and rock
move downslope under the force of gravity.
Types of mass movement the various types of
movement include creep, landslide, flows,
topples, slump, falls and debris avalanche
(figure 10.3).
1. Creep is the slow downhill movement of soil
wherein the steeper the slope means faster
creep.

37. 2. Flow is characterized by mass movements of
material containing a large amount of water.
3.landslide which also called landslip, is arapid
movement of a large mass of earth and rocks
down a hill or a mountainside.
4.Topples occurs when blocks of rock pivot and
fall away from a slope.
5.Slump is the downward movement of a block
of material along a curved surface.

38. 6.Falls or rockfall occurs when rocks or rock
fragments fall freely through the air.
7.Debris avalanche is a variety of very rapid to
extremely rapid debris flow.