The document discusses the lithosphere, which is the outermost solid shell of the Earth composed of the crust and upper mantle. It is divided into three main sections. The first section introduces the lithosphere and describes its composition and structure. The lithosphere consists of oceanic and continental crust and the upper mantle. The second section discusses various geological processes that affect the lithosphere like earthquakes, volcanic eruptions, and plate tectonics. The third section describes the chemical composition and types of rocks found in the lithosphere.

1. पर्यावरण एवं संपोष्र् ववकयस संस्थयन
Institute of Environment and Sustainable Development
Course: M.Sc.(Tech) Environmental
Science and Technology

2. INTRODUCTION
 The Earth is divided into 4
“Sub-systems” or “Spheres”
namely:
 ATMOS(Gaseous)-SPHERE.
 HYDRO(Water)- SPHERE
 LITHOS(Rocky)-SPHERE
 BIOS(Life)-SPHERE
 They are interdependent and
function as a whole.

3. LITHOSPHERE
 Derived from GREEK word
LITHOS meaning Rocky/
Stone.
 It is primarily the rocky and
stony part covering the whole
earth surface ; on which the
interaction of the other Geospheres happen.
 The term was coined by
JOSEPH BARRELL (1914) who
first studied the motion of
lithosphere over a molten layer
i.e. Aesthenosphere.

4. PROCESSES OF STUDYING LITHOSPHERE
REMOTE SENSING
(SATELIITE IMAGERY)
VOLCANIC ERUPTION
EARTHQUAKE

5. PROCESSES OF STUDYING LITHOSPHERE(contd..)
•P-WAVES, or primary waves, are the
fastest moving waves. They originate
in the focus and move outward through
all states of matter. P-waves cause
back and forth motion in matter. Can pass
through liquid medium.
•S-WAVES, or secondary waves, originate at
the focus and pass only through
solids, causing movement from side to
side. Cannot pass through liquid medium.
•L-WAVES, or long waves, are surface
waves. They are the slowest of the
three wave types. L-waves affect the
surface of the land by causing it to
rise and fall like waves on an ocean.

6. Tectonic Plate Theory

7. Tectonic Plate Theory (contd..)
Three types of plate boundaries exist, characterized by the way the plates move
relative to each other. They are associated with different types of surface phenomena.
The different types of plate boundaries are:
1.
Transform boundaries (Conservative) occur where plates slide or, perhaps
more accurately, grind past each other along transform faults. The relative
motion of the two plates is either sinistral (left side toward the observer) or
dextral (right side toward the observer). The San Andreas Fault in California is
an example of a transform boundary exhibiting dextral motion.
2.
Divergent boundaries (Constructive) occur where two plates slide apart from
each other. Mid-ocean ridges (e.g., Mid-Atlantic Ridge) and active zones of
rifting (such as Africa's East African Rift) are both examples of divergent
boundaries.
3.
Convergent boundaries (Destructive) (or active margins) occur where two
plates slide towards each other commonly forming either a subduction zone (if
one plate moves underneath the other) or a continental collision (if the two
plates contain continental crust). Deep marine trenches are typically associated
with subduction zones, and the basins that develop along the active boundary
are often called "foreland basins". Examples of this are the Andes mountain
range in South America and the Japanese island arc.

8. STRUCTURE OF LITHOSPHERE

9. STRUCTURE OF LITHOSPHERE(contd..)
 Oceanic Lithosphere
 It consists mainly of mafic(rich in magnesium and iron) crust and ultramafic(over 90% mafic) mantle and is
denser than continental lithosphere.
• Continental Lithosphere
 It is also called the Continental crust. It is the layer of igneous, sedimentary rock that forms the continents
and the continental shelves. This layer consists mostly of granitic rock.
 CRUST:
 It is the outermost layer of the earth with average density of 2.8- 3.0 g/cm3 and average thickness of 30 km. It
consists of the continental crust and the oceanic crust. Life exists in this layer.
 MANTLE:
 It is the second layer of the earth and extends from 30km- 2900km with an average density of 2.7 g/cm3 .
 It contains 83% of the total volume and 68% of the total mass of the earth.

It is made up of silicate rich iron and magnesium and is divided from the crust by a discontinuity called as
MOHOROVICIC DISCONTINUITY.
 CORE:
 It is the deepest layer of earth. It extends from a distance of 2900km – 6371 km with an average density of 4.3-
11 g/cm3 . Mantle and core boundary is called as WEICHART- GUTENBERG Discontinuity.
 Core volume is 16% of earth’s total volume and core mass is 32% of earth’s total mass.
 It is further divided into 2 sub-zones by the discontinuity called as LEHMANN- BULLEN Discontinuity.
 OUTER CORE: (2890km- 5150km)
 INNER CORE: (5150km-6371km)

10. CHEMICAL COMPOSITION OF LITHOSPHERE
According to E. Seuss the earth’s layers can
be broadly divided into 3 types on the basis
of chemical composition:
 SIAL- located below crust, average
density is 2.7 g/cm3, thickness ranges
between 50-300km; dominated by acid
materials.
 SIMA- located below sialic layer, average
density is 2.9- 4.7 g/cm3 , thickness
ranges between 1000- 2000km;
dominated by basic matter
 NIFE- made up of heavy metals, avg.
density is 11 g/cm3 . Diameter is 688O km.
Magnetic property.

11. ROCKS
 Igneous Rock
Igneous rocks are formed from the molten liquid minerals
that lie below the earth's crust. They're formed from magma
that cools beneath the earth's surface or from lava that cools
upon the earth's surface. These two methods of igneous rock
formation are known as intrusive and extrusive, respectively.
Basalt is the most common type of igneous rock and it covers
the ocean floor and thus, exists over two-thirds of the earth's
surface.
 Sedimentary Rock
Sedimentary rocks are formed by the lithification
(cementing, compacting, and hardening) of existing rock or
the bones, shells, and pieces of formerly living things. Rocks
are weathered and eroded into tiny particles which are then
transported and deposited along with other pieces of rock
called sediments. Approximately three-quarters of the
earth's bedrock on the continents is sedimentary.
 Metamorphic Rock
Metamorphic rock, which comes from the Greek to "change
form," is formed by applying great pressure and temperature
to existing rock converting it into a new distinct type of rock.
Igneous rocks, sedimentary rocks, and even other
metamorphic rocks and be modified into metamorphic
rocks.

12. SOIL
It can be defined as ‘any part of earth crust on which plants root.’ The
whole process of soil formation can generally be divided into 2 stages.:
 Weathering
 Pedogenesis

13. SOIL PROFILE
Soil depth worldwide averages a mere six inches
(15 cm). Soil and its underlying layers are
classified into layers known as "horizons." From
the surface to the bedrock, these layers are:
 O Horizon - The top layer of soil, composed
primarily of organic material, such as the
litter of leaves and plants, insects, and
microorganisms.
 A Horizon - Also known as the topsoil, where
seeds germinate and plants' roots thrive.
Composed of sand and silt. Minerals and clay
have been removed in a process known as
eluviation.
 B Horizon - Also known as the subsoil, this
layer contains mineral deposits that have
settled down from upper layers. Also called
layer of Illuviation.
 C Horizon - This layer is called the regolith
and consists of rocks and little organic
material (even roots don't penetrate this
layer).
 R Horizon - The "R" in R horizon stands for
rock and it refers to the unconsolidated rock
or solid bedrock of this layer.