The document provides information about various earth processes and earth history topics. It discusses how the Earth formed approximately 4.6 billion years ago from a cloud of gas and dust. It also describes tectonic plate movements, the rock cycle, erosion and weathering, fossils and evolution, climate changes, and human influence on the Earth. Another section covers internal Earth processes like volcanoes and earthquakes that are caused by pressure and density differences. It also explains the rotation and revolution of the Earth. The document concludes by defining and describing weathering processes like mechanical, chemical, hydrolysis, oxidation, carbonation, and dissolution weathering.

1. Topic:
EARTH PROCESS AND EARTH HISTORY
INSTRUCTOR: PROF. KANAYA LAL KHATRI
GROUP MEMBER: K-22CE037 Aisha Hassan
K-22CE104 Yasir Ahmed
K-22CE050 Kashif Ali
K-22CE017 Soonh Batool
MUET SZAB CAMPUS KHAIRPUR MIR’S

2. Earth History
The Birth of Earth:
Approximately 4.6 billion years ago, our planet
was formed from a massive cloud of gas and dust
called the solar nebula.Through the process of
accretion, these particles came together, forming
the Earth as we know it today.
EARTH STORY AND PROCESSES

3. Tectonic Plate Movements
Earth outer shell is divided
into several large and small
pieces called tectonic
plates.These plates are
constantly moving, albeit
slowly, due to the convective
currents in the underlying
mantle.Plate movements give
rise to earthquakes, volcanic
activity, and the formation of
mountains.

4. The Rock Cycle
Rocks on Earth undergo continuous
changes through the rock cycle.It
involves three main processes:
weathering and erosion,
transportation, and deposition;
followed by compaction and
cementation, forming new
sedimentary rocks.With the
application of heat and pressure,
sedimentary rocks can undergo
metamorphism and transform into
metamorphic rocks. And through
melting and solidification, igneous
rocks are formed.

5. Erosion and Weathering
• Erosion and Weathering:Weathering is the
process that breaks down rocks into smaller
pieces through exposure to elements like wind,
water, and temperature changes.Erosion
involves the movement of these weathered
particles by forces like water, wind, glaciers, and
gravity.These processes shape the Earth's
surface by creating valleys, canyons, and other
geological features.

6. Earth's Geological Time Scale
The Earth's history is divided into different time
periods to understand the events that occurred
over billions of years.The Geological Time Scale
includes eons, eras, periods, and epochs, marking
significant geological and biological changes
throughout Earth's history

7. Fossils and Evolution
• :Fossils are the preserved remains or traces of
ancient plants, animals, and other
organisms.They provide valuable evidence of
past life forms and contribute to our
understanding of evolution and Earth's
history.By studying fossils, scientists have
uncovered remarkable insights into the
development of life on Earth

8. Climate Changes
• :Earth's climate has undergone significant
changes throughout its history.Factors such as
variations in solar radiation, atmospheric
composition, and volcanic activity have
influenced climate shifts.Understanding past
climate changes helps us predict and mitigate
the impacts of modern-day climate change

9. Human Influence on Earth
• :In recent times, human activities have begun to
shape the Earth's environment on a global
scale.Factors like deforestation, pollution, and
the emission of greenhouse gases are causing
ecological imbalances and climate change.It is
crucial for us to understand the Earth's
processes and history to take responsible actions
and preserve our planet for future generations.

10. Topic: Internal process of Earth
• Internal processes come from
the Earth's internal sun, and
the movement of the
lithospheric plate is the most
obvious example. Internal
processes induced by
disruptions in the earth's
crust include volcanoes and
earthquakes. Volcanic
Eruption: A volcanic
eruption occurs when lava
and gas are expelled from a
volcano, sometimes
violently..

11. The eruption of volcanoes is caused by pressure and
density. The magma rises because it has a lesser
density than the surrounding rocks, similar to air
bubbles in syrup The density of the magma and the
weight of the rocks above it determine whether it rises
to the surface or to a depth. Earthquake: An
earthquake is a violent shaking of the Earth's surface
produced by movement in the Earth's crust. An
earthquake occurs when two slabs of the earth move
past one another. When seismic waves move over the
globe, they shake the land and everything on it, but
when they strike the earth's surface, they shake the
ground and everything on it.

12. Rotation and Revolution are two
motions of the earth
• .When earth spins or rotates around its axis, that movement of
spinning is called Rotation of Earth. And when earth spins or
revolves around the sun, that movement is called Revolution of
Earth. Classification of Earth Movements: Endogenetic Movements:
Sudden Movements: Volcanic Landforms: Exogenetic Forces—
Weathering and Erosion: Earth’s crust and its surface are constantly
evolving (changing) due to various forces emanating from below
(endogenic forces) as well as above the surface of the earth
(exogenic forces). These forces cause physical and chemical changes
to the geomorphic structure (earth’s surface). Some of these changes
are imperceptibly slow (e.g. weathering, folding), some others are
gradual (e.g. erosion) while the remaining are quite sudden
(earthquakes, volcanic eruptions). Geomorphic: relating to the form
of the landscape and other natural features of the earth’s surface.
Geomorphic agents: mobile medium (like running water, moving ice
masses or glaciers, wind, waves, currents etc.) which removes,
transports and deposits earth materials.

13. • Geomorphic movements: large scale physical and chemical changes
that take place on the earth’s surface due to geomorphic processes.
Earth Rotates About Its Axis. Earth-Moon System Orbits a
“Gravitational Centre” The Earth Revolves Around the Sun Once a
Year. The Sun and Earth Revolve Around the Solar System
“Gravitational Centre” The Earth’s Orbit Precesses every 25,770
years. The Sun Revolves Around the Galaxy Once Every 250 Million
Years. For Earth to make one complete revolution around the Sun
takes 365.24 days. During one revolution around the Sun, Earth
travels at an average distance of about 150 million km. Earth
revolves around the Sun at an average speed of about 27 km (17 mi)
per second, What is a landslide? A landslide is a mass movement of
material, such as rock, earth or debris, down a slope. They can
happen suddenly or more slowly over long periods of time. When
the force of gravity acting on a slope exceeds the resisting forces of a
slope, the slope will fail and a landslide occurs.

14. Weathering
Weathering is a fundamental geological process that involves
the breakdown and alteration of rocks and minerals at or near
the Earth's surface. It is a crucial step in the formation of soils
and the cycling of materials through the Earth's crust.
There are two main types of weathering:
1. Mechanical (physical) weathering
2. Chemical weathering.

15. Mechanical (Physical)
Weathering
• Frost Action (Frost Wedging): When water seeps into
cracks and crevices in rocks and then freezes, it expands,
exerting pressure on the surrounding rock and causing it to
fracture.
• Thermal Expansion and Contraction: Daily
temperature fluctuations can cause rocks to expand when
heated and contract when cooled. Over time, repeated
expansion and contraction can lead to the fracturing of rocks.
Mechanical weathering involves the
physical breakdown of rocks into
smaller fragments without changing
their chemical composition. Various
processes contribute to mechanical
weathering, including:

16. • Biological Activity: Plant roots, burrowing animals, and
other organisms can contribute to mechanical weathering by
exerting pressure on rocks, breaking them apart.
• Abrasion: The wearing away of rocks through the
mechanical action of wind, water, or ice carrying abrasive
particles.
• Exfoliation (Pressure Release): Rocks formed under
pressure deep within the Earth's crust can expand when they
are exposed at the surface due to the removal of overlying
rocks. This expansion leads to the outer layers of the rock
peeling off in layers, similar to an onion.

17. Chemical Weathering
• Hydrolysis: Water reacts with certain minerals in
rocks, leading to the breakdown of the minerals and the
formation of new minerals and compounds.
• Oxidation: Oxygen in the air reacts with certain
minerals, especially those containing iron, leading to the
formation of iron oxides, commonly known as rust.
Chemical weathering involves the alteration
of the chemical composition of rocks and
minerals due to chemical reactions with
water, air, and other substances. Common
processes of chemical weathering include:

18. • Carbonation: Carbon dioxide from the atmosphere
dissolves in rainwater to form a weak acid known as
carbonic acid. Carbonic acid reacts with calcium
carbonate-containing rocks (like limestone) to dissolve
and form calcium bicarbonate, which is carried away in
solution.
• Dissolution: Water can dissolve soluble minerals, such
as halite (rock salt) and gypsum, removing them from
the rock matrix.
 NOTE: Chemical weathering can be more significant in regions with
abundant rainfall and warm temperatures, as water is a crucial agent in
many chemical reactions.

19. Thankyou!