EMTECH-PPT_GROUP-2 (1).pptx

Mineral refers to a naturally occurring, inorganic
substance with a crystalline* structure.
*Crystals are composed of a repeating structural
unit composed of atoms of one or more elements.
The elements present and their amount in a crystal
alter their qualities, affecting the minerals they
form.

Color – easy to observe but is not the most reliable
reference for identification of minerals. Impurities may affect
the color of minerals depending on their amount.
Streak – the color observed when the mineral is finely
powdered.
Hardness – the mineral’s resistance to scratching. This is
measured using the Mohs scale of hardness.
Crystal structure – the geometric arrangement of atoms in
the crystalline form of minerals.

Cleavage – the tendency to break along parallel layers. Minerals have
different zones of weakness and will, therefore, break into varied shapes
when force is applied.
Fracture – the breaks in the mineral that are irregular in shape.
Fractures mostly result from the lack of well-defined zones of weakness.
Luster – the way a mineral reflects light. The luster of minerals can be
metallic, pearly, vitreous, or earthy.
Density – depends on the kinds of atoms that comprise the mineral and
how its crystal structure is packed. The formula for density is mass
divided by volume.

Minerals are often formed in a liquid
environment, such as water solutions or
magma.
When temperature decreases, bonds
eventually begin to form between the
atoms and start forming nucleation centers
that will soon become crystals.

Mineral formation may also occur in cool water
solutions provided that there is a high concentration
of ions.
The charges in these ions pull them together,
resulting in the precipitation of crystals within the
solution.
Large crystals are the result of slow cooling process
or high water content.
Small or even microscopic crystals result from rapid
cooling or the presence of a small volume of water.

Rocks are formed from an
aggregation of one or
more minerals and other
substances that are
cohered into a solid
structure.

Igneous rocks are rocks that are formed when
molten rocks (lava or magma) cool and harden.
The time it takes for the magma to cool determines
the texture of the rock.
Two-thirds of the Earth’s crust is composed of
igneous rocks. Examples of igneous rocks are
andesite, pumice, basalt, obsidian, and rhyolite.

Sedimenatary rocks are rocks that
are formed from previously
existing rocks that have been
broken down into small particles or
have been dissolved in solutions.
These particles are transported by
moving water and are deposited as
sediments.

The weight of each deposited
layer of sediments increases the
pressure on the lower layers,
squeezing water out and packing the
particles tighter in a process known
as compaction.

Chemical deposits then fill the spaces
between the particles, precipitate, and
hold the particles together. This process
is called cementation.
Examples of sedimentary rocks are
breccia, conglomerate, sandstone,
shale, and siltstone.

These are previously existing rocks that
have been in contact with high temperature
or pressure, changing their chemical
characteristics and turning them into a
different rock.
Examples of metamorphic rocks are gneiss,
slate, quartzite, schist, and marble.

A process by which rocks
are continuously formed
and destroyed.
Rock cycle demonstrate
how rocks arise from
other rocks.

Exogenic process refers to activities or
phenomena that occur on the Earth’s
surface.

Weathering is a process which reduces the size of rocks
and prepares materials for transport. Weathering can
occur mechanically or chemically.
Mechanical weathering – the process of breaking down of
rocks without changing their chemical composition. Changes in
temperature, wind, water, roots of tress and plants, pull of
gravity, and burrowing animals contributes to this process.
Chemical Weathering – the breakdown of rocks by chemical
mechanisms. This process usually involves water and how it
reacts with other substances.

Hydration is the reaction that occurs when
the minerals in a rock dissolve when they
come in contact with water.
Carbonation is the reaction between rocks
and carbonic acid formed by the dissolution
of carbon dioxide in water.
Oxidation causes rocks to become fragile.

The mixture of different products of weathering
and nondecaying organic matter, known as
humus, makes up the soil.
This readily movable mixture is found on top of a
stable layer of bedrock.
Different soil types are identified based on certain
factors such as type of parent rock, climate, period
of accumulation, elevation, amount of rainfall, and
other environmental variables.

The arrangement and distribution of
particles in the soil are also factors that
can affect fertility.
Soil fertility refers to the amount of
nutrients that is essential for plants to
grow.

The components of soil pile up and are
physically removed from their place
through the process of erosion.
The materials are transported to different
locations by natural elements such as
moving water, wind, gravity, and
animals.

Mass movement or mass wasting – displacement of
materials down from a higher location.
There are different mass movements, depending on
the materials involved or the manner of movement.
The two types of mass movement of soil and rocks are:
(1) Creep – slow movement of large quantities of
soil over a long period of time.
(2) Landslide – sudden and rapid movement of soil
and rocks.

Endogenic processes refer to the activities
or forces in the interior of the Earth.

Although Earth's surface significantly lost heat, its inner
layers have high temperature.
The heat that the planet produces is almost the same
as the amount it loses, keeping temperature constant.
Radioactive decay is the phenomenon that maintains
the production of heat inside the Earth.
The radioactive elements within the planet, such as
uranium, decay and produce heat in the process.

Diastrophism – a geological process that forms
structures such as mountains, valleys, and plateaus on
the crust. The movements of crustal plates.
Magmatism – a geological process by which magma is
produced by partial melting of subsurface rocks. Magma
is pushed upward by pressure through vents and can
reach the Earth’s surface.
The displacement and deformation of rock layers in the
Earth’s crust and mantle.

The applied force that causes Earth's deformations is called
stress. Stress is subdivided into three major types that may be
observed as a single event or in combinations:
Tensional stress – provides a stretching pressure away from
a central plane and results in an increase in total volume.
Shearing stress – the pressure applied to opposite directions
from a parallel central plane that results in a significant change in
the initial shape of the rock layer.
Compressional stress – Imposes a squeezing pressure
toward a central plane and results in a decrease in total volume.

Photo retrieved from https://bkkentweek.com/

Folds – wavelike plastic deformations in rock layers that
are the result of horizontal compressional stresses.
There are three types of folds:
Monocline fold – involves a slight double flexure of
parallel rock layers.
Anticline fold – upwarping of rock layers that results
in an arch-like structure with a convex-up configuration.
Syncline fold – downwarping of rock layers is
observed.

Photo retrieved from ResearchGate

Joints – brittle deformations where fractures are
present in the rock layer, but the movement of
rock materials is not evident.
Faults – breaks in rock layers in which a
significant movement going toward opposite
directions occurs.

Normal or dip-slip fault – develops from vertical tensional stress acting on
opposite rock slabs, resulting in one slab that is displaced upward and the other slab
that is downward.
Reverse fault – occurs when compressional stress occurs between opposite rock
slabs, causing one displaced upward slab and another that is moved downward.
Graben fault – produced when tensional stress results in the down-dropping of a
central slab of a rock layer.
Horst fault – uplifting of a rock layer that is caused by the interactions of two
reverse faults.
Strike-slip fault – horizontal movement of two rock layers that are parallel to each
other, resulting from shearing stress.

The theory of plate tectonics states
that the Earth’s crust is
subdivided into massive plates
that seem to drift upon the Earth’s
softer mantle.

Divergent plate movement is when
two plates move away from each
other.
It is scientifically documented to be the
main cause of seafloor spreading.

Convergent plate movement is when
plates may move toward each other
and collide.
Convergent plate movement includes
subduction.

Subduction is when the thinner and denser
oceanic plate is forced to slide under the much
thicker continental plate.
Subduction zone is the term for the area of
constant contact where the slab going downward
and the overriding slab is produced.

Lateral slipping plate movement refers to when
plates may come in contact and produce
tremendous pressure that is oriented sideways
from each other in opposite directions.
At some point, the pressure building up between
the contact areas of these laterally oriented plates
slip apart, producing earthquake.

The continental drift theory was among the first attempts to
explain the presence of similar species of animal and
plant fossils in different continents.
The theory was first proposed in 1912 by Alfred Lothar
Wegener, a German geophysicist.
The theory was later presented with much more details in his
book The Origin of Continents and Oceans in 1915.
Wegener had deduced that the shapes of the continents we
have today may be fitted together, similar to a puzzle, to
produce one big supercontinent that he called Pangaea.

Photo retrieved from Encyclopedia Britannica

EMTECH-PPT_GROUP-2 (1).pptx

Recommended

Recommended

More Related Content

Similar to EMTECH-PPT_GROUP-2 (1).pptx

Similar to EMTECH-PPT_GROUP-2 (1).pptx (20)

Recently uploaded

Recently uploaded (20)

EMTECH-PPT_GROUP-2 (1).pptx

Editor's Notes