ES

• The Earth was formed from the process of accretion

  wherein gasses and dust of cloud was attracted by

  gravitational energy.
• When masses compacted it formed planetesimals.
• In the process, due to the collision of these masses, heat was

  generated.
• Accretion This process formed the earliest stage of

  planet Earth which is molten in state and heat is

  trapped in the core of the planet.
• Earth is considered as thermal engine since its main source of internal heat

  come from the produced decay of some naturally occurring isotopes from its

  interior.
• This process is known as radioactive decay by which the spontaneous

  breakdown of an atomic nucleus causes the release of energy and matter

  from the nucleus.
• Some of the isotopes are potassium – 40, Uranium - 235, Uranium - 238

  and Thorium - 232.
• The more a person descend into Earth’s interior, the amount of pressure

  increases due to the force pressing on an area caused by the weight of an

  overlying rocks.
• The pressure near the center is considered to be 3 to 4 million times the

  pressure of atmosphere at sea level.
• Again, because rocks are good

  insulators, the escape of heat from Earth’s surface is less than the heat

  generated from internal gravitational attraction or squeezing of rock, so heat

  builds up within.
• At high temperature, the material beneath will melt towards the central part

  of the earth.
• Due to increase in pressure and presence of heavier

  materials towards the earth’s center, the density of

  earth’s layers also increases.
• the materials of

  the innermost part of the earth are very dense.
• The inner

  core as the inner most layer is composed primarily of iron

  and nickel which contributes to the density in the core

  that ranges between 12,600-13,000 kg/m3.
• Physical weathering (mechanical weathering)

  is the disintegration of rocks, breaking them into smaller pieces due to any

  force (natural or anthropogenic) without altering its composition (Guzman,

  et al., 2016).
• Frost wedging

  repeated freezing and thawing of water found in the cracks of rocks called

  joints pushes the rock to the breaking point.
• Abrasion

  wearing a way of rocks by colliding particles
• Exfoliation

  reduced pressure on igneous rock causes it to expand and allows slabs

  of outer rock to break off in layers (Tarbuck, Lutgens & Tasa, 2014)
• Biological Activity

  animals, microbes and plants as agents of mechanical weathering, such

  as application of pressure on rocks, burrowing animals.
• Chemical Weathering

  is the decomposition of rocks involving chemical reactions causing change

  in their chemical makeup as influenced by low pressure, low temperature,

  and the water and oxygen-rich nature of the Earth’s surface (Guzman, et al.,

  2016).
• Dissolution / Carbonation

  dissociation of molecules into ions; example is the dissolution of calcite

  and salt; removal of rock by acidic rainwater in solution especially

  dissolved CO2 (carbonic acid) -containing rainwater weathers the rock.
• Oxidation

  – rock breakdown by oxygen and water, often giving a rusty-colored

  weathered surface to iron-rich rocks.
• Hydrolysis

  acidic water breakdown of rock producing clay and soluble salts
• Endogenic Process is a geological

  process that was formed, originated, and

  located below the surface of the earth. It

  involves geologic activities such as tectonic

  movements, metamorphism, seismic

  activities and magmatism.
• Two main mechanism which rocks melt: Decompression Melting AND Flux Melting
• Rocks undergo partial

  melting because the minerals

  that compose them melt at

  different temperature.
• Partial

  melting takes place because

  rocks are not pure materials.

  As temperature rises, some

  minerals melt and others

  remain solid.
• Intrusion Magma that moves up into a

  volcano without erupting.

  Like a balloon, this causes

  the volcano to grow on the

  inside. What is meant by the

  intrusion of magma is the

  inclusion of the rock layers

  forming the earth's crust

  (magma does not get out).
• Extrusion An eruption of magmatic

  materials that causes land

  formation on the surface of

  the Earth. Magma extrusion

  causes the formation of

  volcanoes when the gas

  pressure is strong enough

  and there are cracks in the

  earth's crust.
• Plutonism

  In cases where magma

  infiltrates the Earth's

  crust but fails to make it

  to the surface, the

  process of magma

  differentiation gives birth

  to ideal conditions for

  metallogenies and that is

  a kind of Plutonism.
• PLUTONITES MADE: crystallization
• Tensional stress – causes rocks to be pulled apart that

  result to lengthening and break apart.
• Compressional stress – causes rocks to fold or fracture. It

  squeezes rocks together.
• Shear stress – happens when forces slide pass each other in

  opposite direction which results to slippage and translation.
• Faults - A rock under ample stress can crack, or

  fracture.
• Folds - are formed when rocks experienced compressive

  stress and deformed plastically. It causes bending of rocks.

  There are three types of folds: monoclines, anticlines and

  synclines.
• The fracture is called a joint because there is a

  block of rock left standing on either side of a fracture

  line.
• The footwall is the rock that place on top the fault,

  while the hanging wall is below the fault.
• Faults can be

  classified into: Normal Faults, Reverse Faults, and

  Strike-slip Faults.
• Normal faults – are the most common faults at

  divergent boundaries. In relation to the footwall, it

  develops as the hanging wall drops down.