1. THE Solid EARTH
The earth formed approximately 4.6
billion year ago from a nebular cloud to
dust and gas that surrounded the sun. The
dusty material accreted to the nebular
midplane where it formed progressively
larger clumps. Eventually bodies of
several kilometers in diameter
formplanetesimalsed; these are known as.
2. The three layers of earth
The crust- is the thinnest layer in the
earth, making un only 1 percent of the mass
and 2 percent of the volume.
The mantle- is the largest layer in the
earth, making up about 82 percent of the
volume and 68 percent of the mass of the
earth.
The core- makes up 16 percent of the
volume of the earth and about 31 percent
of the mass.
3. Minerals and Rock
MINERALS
Must be distinguished from rock. A
mineral is a chemical compound with a
given composition and a defined
structure.
ROCKS
is a mixture of one several minerals,
in varying proportion.
4. Other Meaning for Rock
Rock are hard mass of the
earth’s surface. Some are just a
few million years old. Others
formed almost 4 billion years ago.
When the earth was young they
are always being added to a new
rock forms.
6. Igneous rocks
Igneous rock (derived from the latin word igneus meaning
of fire, from ignis meaning fire) forms through the cooling and
solidification of magma or lava. Igneous rock may form with or
without crystallitation, either below the surface as intrusive
(plutonic) rocks or on the surface extrusive(volcanic) rocks. This
magma can be derived from partial melts of pre-existing rocks in
either a planet's mantle or crust. Typically, the melting is caused
by one or more of three processes: an increase in temperature, a
decrease in pressure, or a change in composition. Over 700 types
of igneous rocks have been described, most of them having
formed beneath the surface of Earth's crust. These have diverse
properties, depending on their composition and how they were
formed.
7. Sedimentary rocks
Sedimentary rocks are types of rock that are formed
by the deposition of material at the Earth's surface and
within bodies of water. Sedimentation is the collective
name for processes that cause mineral and/or organic
particles (detritus to settle and accumulate or for minerals
to precipitate from a solution. Particles that form a
sedimentary rock by accumulating are called sediment.
Before being deposited, sediment was formed by
weathering and eroison in a source area, and then
transported to the place of deposition by water, wind, ice,
mass movement or glacier which are called agents of
denudation.
8. Metamorphic rocks
Metamorphic rocks arise from the
transformation of existing rock types, in a process
called methamosposis, which means "change in
form". The original rock (protolith) is subjected to
heat and pressure, (temperatures greater than 150
to 200 °C and pressures of 1500 bars) causing
profound physical and/or chemical change. The
protolith may be sedimentary rocks, igneous rock
or another older metamorphic rock.
9. Diastrophism
Diastrophism refers to deformation of the Earth's crust, and
more especially to folding and faulting. Diastrophism can be
considered part of geotectonics. Diastrophism comes from the
Greek word meaning a twisting.
Cases of Diastrophism Movement
The result of pressure exerted by
convection currents in the mantle.
Meteorite impact
Combination of gravity and erosion
10. VOLCANISM
is the phenomena connected with
volcanoes and volcanic activity. It
includes all phenomena resulting
from causing magma within the crust
or mantle of a planet to rise through
the crust and from volcanic rocks on
the surface.
11. Driving forces of Volcanism
PLATE TECTONICS
from late(tectonicus) from the Greek
(pertaining to building) is a scientific theory that
describes the large scale motions of earth
lithosphere.
movement of molten rock in the planet
mantle caused by thermal convection
currents, couple with gravitational effects
of changes on the earth surface
12. Aspects of Volcanism
Volcanoes
are place where magma reaches the earth surface.
Intrusions
these are formed where magma pushes between
existing rock, intrusions can be in the form of
batholiths, dikes, and layered intrusions.
Hydrothermal vents
these includes Geyser, Hot spring, and munpots.
They are often used as a source of geothermal
energy.
13. Volcanic Winter
the amount of gas and ash emitted by volcanic
eruption has a significant effect on the planet climate.
EARTHQUAKE
also known as quake, tremor or temblor. Is the
result of a sudden release of energy in the earth’s
crust that create seismic wave.
are generally associated with plate tectonics
activity but some earthquakes are generated as a
result of volcanic activity.
