OVERVIEW: Theories on How the continents came to its present Position Rocks Minerals Soil Erosion LEAVE A COMMENT. :D

1. Earth’s Layers
Lithosphere – Rocks, Minerals, Soil and Erosion

2. WHY STUDY EARTH SCIENCE?
1. Look for new energy sources that will have a minimal effect on
climate.
2. Develop other energy and mineral resources.
3. Study the impact of human activities and design methods to protect
the planet.
4. Establish ways to prevent severe damage caused by natural
phenomena like volcanic activities, earthquakes, and floods.
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3. EARTH’S LAYERS
PHYSICAL COMPOSITION
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CHEMICAL COMPOSITION

4. EARTH’S LAYERS-Chemical Composition
a. Crust
 Upper layer of the lithosphere and is mostly solid rock.
 It has two distinct regions:
1. Continental Crust/ Continental Lithosphere
 Composed of silica-alumina-rich rock called sial that
commonly occurs as granite.
2. Oceanic Crust/ Oceanic Lithosphere
 Consists of silica-magnesia-rich material called sima that is
typically made up of basalt.
b. Mantle
 Next layer to the crust and it contains most of the earth’s crust.
 It is about 2,800 km thick.
 Primarily solid but materials can flow slowly like putty – this explains
the movements of the crustal plates.
1. Upper mantle – composed of silicates of metallic compounds.
2. Lower mantle – rich in aluminum and magnesium
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Moho
Moho (Mohorovicic Discontinuity) – Borderline of the Earth’s crust; divides the crust from underlying mantle.
– named after the name of the discoverer (1901), Andrija Mohorovicic, aYugoslavia seismologist.

5. EARTH’S LAYERS-Chemical Composition
c. Core
 Innermost part of the earth, which is about
3,500 km thick.
 1/3 of earth’s mass.
 It has two layers:
1. Outer core – Made up very, very hot molten
metals namely, iron and nickel
– 2,266 km thick
2. Inner Core – made up of solid iron and nickel
– about 1,200 km thick
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Gutenberg Discontinuity – Discontinuity between the mantle and the outer core.
– named after a German seismologist, Beno Gutenberg, who discovered it in 1914

6. EARTH’S LAYERS-Physical Composition
a. Lithosphere
 “rock sphere”
 It is a cold, outer rigid shell of the earth’s structure.
 This layer is broken onto tiny pieces called plates.
b. Asthenosphere
 “weak sphere”
 It is the zone directly under the lithosphere.
 It has plastics behavior because it has the ability to flow.
 It is responsible for the movement of crustal plates.
c. Mesosphere
 The region between the asthenosphere and the core-mantle boundary.
 The pressure in this area compensates with the high temperature and
results to a stronger and firmer layer.
d. Core
 It is the innermost layer which marks a change in both the physical and
chemical composition.
 The circulation of the liquid outer core leads to the production of magnetic
field.
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7. Continental DriftTheory, Seafloor Spreading, and Plate
TectonicsTheory
a. Continental DriftTheory
 Hypothesized that continents were once a large
supercontinent that drifted apart from each other.
b. Seafloor Spreading
 It is a lithospheric evolution theory wherein ocean floor
move outward from the vast ocean ridges.
c. PlateTectonicsTheory
 Aims to explain the movements and deformations of the
outer layers of the earth.
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8. Continental DriftTheory, Seafloor Spreading, and Plate
TectonicsTheory
a. Continental DriftTheory
 Proposed by a German Meteorologist,Alfred
Wegener in 1915.
 Wegener theorized a supercontinent called
Pangaea – “all earth”, had drifted apart and
later divided into two super continents:
1. Laurasia
2. Gondwanaland
 This was largely unaccepted in the northern
hemisphere where geologists don not
believe that rock movements of that type
could happen.
 This was widely accepted by the geologists
in the southern hemisphere.
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AlfredWegener

9. Continental DriftTheory, Seafloor Spreading, and Plate
TectonicsTheory
a. Continental DriftTheory
 Some of the proofs thatWegener used in the continental drift theory
were:
1) The fit of the continents
2) Distribution of fossils wherein same species were discovered on different
continents
3) Same series of structure and rock types at different locations like South
America, Africa, India, Antarctica, and Australia
4) Glaciation on some continents at same period in the geologic past
5) Ancient climates; and
6) The evidence roaming of the Earth’s polar regions.
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10. Continental DriftTheory - Fossil Evidence
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12. Continental DriftTheory, Seafloor Spreading, and Plate
TectonicsTheory
b. Seafloor Spreading
 “Recycling Process”
 It is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic
activity and then gradually moves away from the ridge.
 It helps explain continental drift in the theory of plate tectonics.
 Proposed by Harry Hess in 1960s. He found out how oceanic mountain ranges, called oceanic ridges are
essential to the tectonic movement that results in the drift of continents.
 According to this theory, the ocean floor is about a few hundred million years old, making it significantly
younger than the continents.
 This supports the idea that molten rocks takes a long time to come out of volcanically active oceanic
ridges which later form a new seafloor by
spreading sideways. It then goes back to
the ocean trench.
 New ocean crust scatter away from the ridges
and take with it older sediments and fossils, and
make the continents drift.
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13. Continental DriftTheory, Seafloor Spreading, and Plate
TectonicsTheory
b. Seafloor Spreading
 Seafloor spreading in the East Pacific
Rise pulls the continents of Australia,
South America, and Antarctica away
from each other. It is one of the most
active sites of seafloor spreading,
spreading more than 14 centimeters
annually.
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 MarianasTrench
 The deepest seafloor in the world, the
point where the enormous Pacific plate
descends under the leading edge of the
Eurasian Plate.
 It curves northward from the near island
of Guam and its bottom lies close to
almost 11,000 bellow the PacificOcean’s
surface.

14. Continental DriftTheory, Seafloor Spreading, and Plate
TectonicsTheory
c. PlateTectonicsTheory
 It is the theory that
Earth's outer shell is
divided into several plates
that glide over the
mantle, the rocky inner
layer above the core.
 The movement of
tectonic plates is possible
partly due to internal
forces.
 The plates act like a hard
and rigid shell compared
to Earth's mantle but can
be deformed along the
plate boundaries, zones
along which an
earthquake occurs.
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15. Continental DriftTheory, Seafloor Spreading, and Plate
TectonicsTheory
c. PlateTectonicsTheory
 Plate interiors have fewer earthquakes.
 Most of the world’s active volcanoes are
located along or near the boundaries
between shifting plates and are called plate-
boundary volcanoes.
 Boundaries of several plates on the
marginal areas of the Pacific ocean basin,
which are dotted with many active
volcanoes that form the so-called Pacific
Ring of Fire where plate-boundary
volcanoes such as Mount St. Helens can be
found.
 Different landforms turn due to plate
tectonics.
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16. July 22, 2012 Footer text here16

17. ROCKS
Rocks
 These are naturally occurring substances
which are made up of one or more minerals.
 The study of rocks is known as petrology.
 Rocks are grouped according to the minerals
they contain and the way in which they were
formed.
1. Igneous Rocks
 Lt. igneus – “fire”
2. Sedimentary Rocks
 Lt. sedere – “to settle”
3. Metamorphic Rocks
 Gk. meta – “change” and morphe –
“form”
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18. ROCKS
1.Igneous Rocks
 From Latin word igneus meaning fire.
 These rocks form when hot, molten rock
called magma crystallizes and solidifies.
 This type is divided into two groups:
1.Extrusive or Volcanic Rocks
• Come from that magma that emerged
to the earth’s surface through cracks or
which gushed out of volcanoes and then
gradually cool and solidify.
• Examples:Andesite, Basalt, Rhyolite,
Tuff, and Pumice
2.Intrusive or Plutonic Rocks
• Form when magma inside the earth
solidifies and hardens.
• Examples: Gabbro, Dacite, Granite,
Diorite, ad Peridotite.
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Extrusive or Volcanic Rocks
Intrusive or Plutonic Rocks

19. ROCKS
2. Sedimentary Rocks
 From Latin word sedere meaning to settle.
 These rocks form when loose earth
materials called sediments become
pressed or cemented together.
 This type is divided into three categories:
1.Clastic Rocks
• Formed from clasts, or broken
fragments, of pre-existing rocks and
minerals.
• Examples: sandstone, siltstone, shale;
breccia, conglomerate
2.Chemical Rocks
• Formed from precipitation or
solidification of minerals usually from
seawater or lake water
• Examples: Rock gypsum, Rock salt,
limestone, Chert/flint, halite
3.Organic Rocks
• Form when traces of animals and plants
accumulate and harden.
• Examples: fossiliferous limestone, coal
and peat
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Clastic Rocks
Breccia Conglomerate Sandstone Shale
Chemical Rocks
a
Rock Salt Rock Gypsum Chert Halite Limestone
Organic Rocks
Coal Fossiliferous Limestone Peat

20. ROCKS
3. Metamorphic Rocks
 From Greek word meta meaning change
and morphe meaning form.
 These rocks develop when pre-existing
rock go through mineralogical and
structural changes affected due to high
temperature and pressure.
 It has two types:
1.Foliated
• Minerals have been rearranged into
visible layers, such as slate, schist,
gneiss
2.Non-Foliated
• Does not show layering or banding such
as marble, quartzite and serpentinite.
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Foliated
Non-foliated
Serpentinite

21. The Rock Cycle
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22. MINERALOGY
Mineralogy
 It is the study of minerals, the building blocks of rocks.
 It deals with the identification of minerals and the study of their properties, origin, and
classification.
 There are about 4,000 minerals on earth and all of these have five common characteristics:
1. Minerals are formed naturally.
2. Minerals are inorganic.
3. Minerals are solid.
4. Minerals have a specific chemical composition.
5. Minerals are made up of orderly arrangements of atoms with definite crystal
structure.
 Minerals are not formed in the same way.
 Some form through evaporation of saltwater on the Earth’s surface.
 Others form from water mixtures that leach through rocks far below the ground.
 Some form when mixtures of really hot molten rock cool.
 Each minerals has a unique property.
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23. MINERALOGY
Properties of Minerals
1. Color
 It depends on the elements present when the
mineral was formed.
 It is the easiest property to observe but is not reliable
for identification.
 Different minerals have the same color sometimes.
• For example, pyrite is also called “fool’s gold”
because it has a gold color but does not contain
any gold atoms.
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24. MINERALOGY
Properties of Minerals
2. Streak
 It is the color of the mineral when it breaks and is powdered.
 It is more helpful way to identify a mineral compared to color.
• For example, hematite(right) and galena(left) are both dark gray on color but hematite’s streak
is red while galena’s is gray.
 However, streak can only be used for minerals softer than the streak plate, such as
unglazed porcelain tile. (white square tile in the image)
 When minerals have white or colorless streak, this test is not helpful.
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25. MINERALOGY
Properties of Minerals
3. Luster
 It is the ability of a mineral to reflect light
falling in its surface.
 It can either be metallic or non-metallic.
• Metallic Luster
• Metallic luster is that of an untarnished
metal surface, such as gold, steel, copper,
galena, pyrite, and hematite.
• Minerals with metallic luster can also be
described as having a "shiny", "dull", or
"iridescent" luster.
• Minerals of metallic luster are opaque to
light, even on thin edges.
• Non-metallic Luster
• Non-metallic luster minerals are generally
lighter in color and show some degree of
transparency or translucency, even though
this may be on a thin edge.
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Pyrite Galena
Diamond Amber
Quartz Rose Quartz
Barite Actinolite
• Adamantine – diamond
• Vitreous or glassy – quartz
• Resinous – Amber, sulfur
• Pearly – Barite
• Greasy – Rose quartz
• Silky – Actinolite
• Earthy – Malachite
• Waxy – Chalcedone
WaxyEarthyMalachite

26. MINERALOGY
Properties of Minerals
4. Crystal
 It is the arrangement of atoms, ions or molecules in a definite pattern that is very useful
in identifying a mineral.
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Isometric
(Cubic)
Hexagonal Tetragonal Trigonal Orthorhombic Monoclinic Triclinic

27. MINERALOGY
Properties of Minerals
5. Cleavage
 It is the tendency of a mineral to break along certain planes to make smooth
surfaces.
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28. MINERALOGY
Properties of Minerals
6. Fracture
 It is a distinct manner of breaking other than a long planar surface such as rough or
jagged edges.
 Minerals that do not exhibit cleavage are said to fracture when broken.
• Some break like glass.
• Some break into splinters or fibers.
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29. MINERALOGY
Some physical qualities of minerals
can be measured like hardness and
specific gravity.
1. Hardness
 It is the resistance to being
scratched.
 It is determined by the
strength of the bonds holding
the minerals together.
2. Specific gravity
 It is the ratio of the mineral’s
density to that of water.
 It is a function of the elements
of which the mineral is made
as well as how they are put
together in a crystal structure.
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Simple Test
A fingernail scratches it easily.
A fingernail scratches it.
A copper penny just scratches it.
A steel knife scratches it easily.
A steel knife scratches it.
A steel knife does not scratch it.
It scratches steel and hard glass easily.
It is harder than any common mineral.
It scratches topaz.
It cannot be scratched, hardest of all
minerals.

30. MINERALOGY
Special Mineral Properties
Property Description Example of Mineral
Magnetism Attracted to magnet Pyrrhotite, magnetite
Fluorescence Emits visible light when exposed to UV light Fluorite
Radioactivity Emits radiation Uraninite
Smell Distinct smell Sulfur
Pyro-electrical Generate a temporary voltage when they
are heated or cooled
Tourmaline, topaz
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31. MINERALOGY
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Examples of Nonmetallic and Metallic Minerals
Nonmetallic Minerals Metallic Minerals
Anhydrite Sulfur Chromite Chalcopyrite
Calcite Quartz Enargite Copper Ore

32. SOIL
Soil
 It covers most land areas.
 Farmers need them for growing plants.
 Soil analysis must be performed first before construction of different buildings an be done.
 Soil is a mixture of weathered rock and decomposed organic matter and is important
product of weathering.
 About 50% of soil comprises rocks and minerals, with the rest being air, water, and organic
matter.
 It is an important material that could support plant life.
 Soil formation happens in the bedrock.
 A great variety of soil types exist depending on the environmental factors such as:
• Climate
• Amount of sand, clay, silt, humus
• Type of parent rock
• Physical features of a place or region
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33. SOIL
Components Of Soil
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Humus It comes from the microbial decomposition of plant
and animal residues.
It is dark brown in color and it provides nutrients like
phosphorus, nitrogen, potassium, and sulfur.
Sand It is derived from the weathering of rocks such as
granite. It is granular and consists of rock and mineral
particles that are very small.
Clay It is formed when certain minerals like feldspar
undergo weathering in the presence of water.
It consists of very fine grain materials.
Loam It is a mixture of sand and silt with a very small
amount of clay.
Silt It contains small rocks with some sand.
It is poor absorbent of water because it dries up
quickly.

34. SOIL
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Classification Of Soil (based on particle size)
Sandy soil It contains the biggest particles, granular and mostly has
very small rock and mineral particles. Water and
nutrients quickly drain away from the plant root zone
Silty soil It is made up of fine particles. It can hold water but airing
around roots is usually not enough.
Loamy soil It contains an ideal mixture of sand and clay. Sand keeps
the soil open and the clay makes sure enough moisture is
retained.
Clay soil It is a compact and contains very small particles. It
absorbs and holds water but creates drainage problem
which has a big effect on growth of plants.

35. SOIL
Three Main Layers of Soil
1. Topsoil
 It is the uppermost layer of the soil.
 It is humus-rich soil with mixture of small grains of
rock and decayed plants and animals, making it
fertile and ideal for planting
2. Subsoil
 It is the layer beneath topsoil.
 It contains clay, sand, pebbles and lager bits of rocks
and it has very small amount of humus or none at
all.
3. Bedrock
 It is a solid rock composed of numerous and large
rock particles and serves as storage for
groundwater, which provides fresh water once
tapped.
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36. EROSION
Sometimes soil causes an environmental problem.
How? It’s because of EROSION. Soil erosion affects
both agriculture and natural environment.
Erosion
 It is a process where rock materials are
transported from one area of the earth’s
surface and deposited t another.
 There are five major agents of erosion.
1. Wind
2. Gravity
3. Running
4. Glaciers
5. Waves
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37. EROSION
Five Major Agents of Erosion
1. Wind
 It erodes the earth’s surface by
picking up light objects like sand.
 Wind erosions generally occurs in dry
areas with little or no vegetation. It
can be compared to a sandblasting
process where the wind rolls and
blows sand grains.
 Examples: sand and dust storms
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2. Gravity
 It is the most important agent in
steep mountains.
 It causes the down-slope movements
of rocks and sediments from higher
to a lower area in a process called
mass movement.

38. EROSION
3. Running water
 It is considered the most powerful
agent of erosion.
 For example, rain carries away soil
and slowly washes away rock
fragments; fast-moving streams and
rivers erodes their banks, forming
bigger alleys.
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4. Waves
 Wave energy does the work of erosion at
the shore.
 Waves erode sediments from cliffs and
shorelines.The sediment in ocean water
acts like sandpaper.Over time, they
erode the shore.The bigger the waves
are and the more sediment they carry,
the more erosion they cause.

39. EROSION
5. Glaciers
 These are the most important agents
of erosion in colder regions where snow
is the predominant form of
precipitation.
 Although it moves slowly, it covers
huge areas.
 The movement of glaciers over land
can be compared to a bulldozer
pushing materials out of their way.
 Rock fragments and sand pulled and
carried away by the glacier as it moves
would further scrape the soil and
bedrock, resulting to greater erosion of
materials than ice alone.
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40. 15-Item Quiz
1. It is a cold, outer rigid shell of the earth’s structure .It
consists of the crust and the upper mantle.
2. It is the discontinuity or the borderline of the Earth’s crust
and the underlying mantle. It is named after aYugoslavian
Seismologist.
3. He proposed the Seafloor SpreadingTheory.
4. It is the study of rocks.
5. These are igneous rocks that form when magma inside the
earth solidifies and hardens. Examples are Gabbro and
Dacite.
July 22, 2012 Footer text here40

41. 6. These rocks form when loose earth materials called
sediments become pressed or cemented together.
7. It is the building blocks of rocks.
8. It is the color of the mineral when it breaks and is
powdered. It can be tested through an unglazed porcelain
tile.
9. It is the tendency of a mineral to break along certain planes
to make smooth surfaces.
10.Give a special property of a mineral.
July 22, 2012 Footer text here41

42. 11.It is a component of soil that is granular and consists of rock
and mineral particles that are very small.
12.Bedrock is composed of numerous and large rock particles
and serves as storage for groundwater, which provides
______?_______once tapped.
13.Type of soil (based on soil particles)that is compact and
contains very small particles.
14.It is considered to be the most powerful agent of erosion.
15.It is the most important agent in steep mountains.
July 22, 2012 Footer text here42

43. 15-Item Answers
1. It is a cold, outer rigid shell of the earth’s structure .It consists
of the crust and the upper mantle.
2. It is the discontinuity or the borderline of the Earth’s crust and
the underlying mantle. It is named after aYugoslavian
Seismologist.
3. He proposed the Seafloor SpreadingTheory.
4. It is the study of rocks.
5. These are igneous rocks that form when magma inside the
earth solidifies and hardens. Examples are Gabbro and Dacite.
July 22, 2012 Footer text here43
1. Lithosphere
2. Moho/ Mohorovic
Dicontinuity
3. Harry Hess
4. Petrology
5. Intrusive or
Plutonic Rocks

44. 6. These rocks form when loose earth materials called
sediments become pressed or cemented together.
7. It is the building blocks of rocks.
8. It is the color of the mineral when it breaks and is powdered.
It can be tested through an unglazed porcelain tile.
9. It is the tendency of a mineral to break along certain planes
to make smooth surfaces.
10. Give a special property of a mineral.
July 22, 2012 Footer text here44
6. Sedimentary Rocks
7. Minerals
8. Streak
9. Cleavage
10.Smell
Magnetism
Radioactivity
Fluorescence
Pyro-electrical

45. 11. It is a component of soil that is granular and consists of
rock and mineral particles that are very small.
12. Bedrock is composed of numerous and large rock
particles and serves as storage for groundwater, which
provides ______?_______once tapped.
13. Type of soil (based on soil particles)that is compact and
contains very small particles.
14. It is considered to be the most powerful agent of erosion.
15. It is the most important agent in steep mountains.
July 22, 2012 Footer text here45
11. Sand
12. Fresh water
13. Clay
14.Water/Running
water
15. Gravity

46. Source
• Worktext in Physical Science
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47. ThankYou!
July 22, 2012 Footer text here47