2. INTRODUCTION TO
ENVIRONMENTAL STUDIES
What do Environmental Studies refer
to …….; ??
It refers to recognizing the Environmental issues and
their management techniques.
It refers to the ways in which the different societies ,
government and the economic sectors use , misuse and
manage the global environment.
It refers to the ways that Man can achieve the
sustainable development of the natural resources, so the
future generation can utilize these resources.
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3. INTRODUCTION TO
ENVIRONMENTAL STUDIES
What is Our Environment?
It is comprising of four major parts;
– Atmosphere
– Lithosphere
– Hydrosphere
– Biosphere
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4. INTRODUCTION TO
ENVIRONMENTAL STUDIES
Atmosphere is composed of two Greek
words, atmos (means vapour) and sphere
means globe.
The air we breath is a part of atmosphere.
It is comprising of gases and water vapour.
It forms the weather, protects from the
Sun’s ultraviolet rays and supply Oxygen to
living things.
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5. INTRODUCTION TO
ENVIRONMENTAL STUDIES
Hydrosphere is composed of (hydro=water)
and (sphere=globe)
It includes all the water bodies (fresh and
marine)
It provides us the water for drinking,
industrial and agricultural purposes.
It also supplies fish as a low cholesterol
meat.
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6. INTRODUCTION TO
ENVIRONMENTAL STUDIES
Lithosphere is composed of (lithos=outer
part of the earth), and (sphere=globe)
It consists of crust and upper mantle.
It has the mountains, valleys and ocean
beds.
It provides us the land and resources.
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7. INTRODUCTION TO
ENVIRONMENTAL STUDIES
Biosphere is composed of (bio=life), and
(sphere=globe)
It comprises of all living things on land, in
sea and freshwater.
All living things are interrelated to each
other as well as they are dependent on other
spheres.
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8. INTRODUCTION TO
ENVIRONMENTAL STUDIES
Inter-relationship of four Spheres;
Atmosphere
Litho
sphere Bio
sphere
Hydro
sphere
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18. LITHOSPHERE
Rocks & minerals:
Lithosphere constitutes of rocks and minerals.
Minerals are defined as naturally occurring,
inorganic, solid, crystalline material with a
specific composition, examples: quartz,
feldspar,
Rocks are defined as the aggregates of
minerals, Andesite (igneous), limestone
(sedimentary), and marble (metamorphic).
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21. IGNEOUS ROCKS
Igneous rocks are formed as a result of cooling
and solidification of magma or lava. They can be
classified into two groups;
Extrusive (volcanic) rocks are those which are formed
on the surface of the earth by cooling and solidification
of lava, they are fine-grained rocks (small crystals)
examples; Andesite, basalt.
Intrusive (plutonic) rocks are those which are formed
beneath the earth surface, when magma is forced
through the vents or cracks in the earth by the
convectional currents, it is cooled and solidified to form
these rocks. Examples; Granite, Gabbro
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22. SEDIMENTARY ROCKS
Sedimentary rocks are formed by the deposition and consolidation of
minerals and organic materials, they are formed in the water and later
on they come on the surface due to uplifting forces. They constitute
about 75-80% of the rocks. They can be divided into three groups;
Clastic sedimentary rocks are formed by mechanical weathering of
other rocks, as a result of weathering rocks are broken into
particles known as sediments which are transported and deposited
elsewhere, forming theses rocks.Sandstone, siltstone,
conglomerate.
Chemical sedimentary rocks are formed by the chemical
weathering of other rocks, the sediments are deposited in the water
to form these rocks.Limestone, rock salt.
Organic sedimentary rocks are contain the dead remains of living
organisms (fossils), coal, oil shale.
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23. Metamorphic Rocks
These are those rocks formed as a result of
transformation of existing rocks under great heat
and pressure, the existing rocks can be igneous,
sedimentary or even metamorphic.They are
formed beneath the earth surface, when rocks are
subjected to great pressure and heat due to the
overlain layers of rocks, or sometimes there is an
intrusion of hot molten magma from the mantle.
Examples; Marble is metamorphosed form of
limestone, quartzite is metamorphosed form of
sandstone and schist is changed from slate and
slate is changed from shale.
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