INTRODUCTION TO GEOLOGY
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Geology
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the study of the solid Earth, the rocks which
comprise it, and the processes.
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Building blocks of rocks
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Made up rocks
ROCKS
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Composed of minerals
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Aggregates of minerals
Supplying things we need (Energy resources
Protecting the environment
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Avoiding geologic hazards
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Understanding our surroundings
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EARTH SYSTEMS
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Atmosphere
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Hydrosphere
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Biosphere
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Geosphere
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Internal heat engine
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External heat engine
EARTH’S INTERNAL PROCESSES:
LAYERS
and Raw materials)
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Earth as a giant machine driven by two heat
engines:
MINERALS
WHY STUDY GEOLOGY?
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IMPORTANT CONCEPTS IN
PHYSICAL GEOLOGY
Earth’s interior
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Crust (oceanic and continental)
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Mantle
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Core (inner and outer)
LITHOSPHERE
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Rigid
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Upper mantle to crust
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Broken into PLATES that are in motion.
ASTHENOSPHERE
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Weak
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Solid but mobile
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Has the property to flow
PLATE BOUNDARIES
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CONVERGENT PLATE BOUNDARY
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Creates trenches
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The top plate is called the overriding plate
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Paleozoic
and the bottom one is the subducting plate.
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Precambrian
GEOLOGY AS A DISCIPLINE
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The earth is our laboratory
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Scale of rock features
CONVERGENT PLATE BOUNDARY
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Macroscopic
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Mesoscopic
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Microscopic
Timing is also important in geology
MAIN BRANCHES OF GEOLOGY
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PHYSICAL GEOLOGY
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Composition processes beneath and on the
surface.
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TRANSFORM PLATE BOUNDARY
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HISTORICAL GEOLOGY
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Origin and development through time.
PHYSICAL GEOLOGY
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VOLCANOLOGY
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SEISMOLOGY
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EARTH’S EXTERNAL PROCESSES
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Monitoring, volcanic processes, hazards.
Earthquake and seismic waves, hazards
ENVIRONMENTAL GEOLOGY
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Interaction between human and geologic
environment.
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ENGINEERING GEOLOGY
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Worn down by surficial processes (agents of
erosion)
GEOLOGIC TIME
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4.6 billion years
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RADIOMETRIC DATING
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GEOLOGIC TIME SCALE
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Cenozoic
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Mesozoic
Chemical composition
GEOPHYSICS
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Study of rocks
GEOCHEMISTRY
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Study of minerals
PETROLOGY
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Metalliferous and non-metalliferous
MINERALOGY
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EARTH
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ECONOMIC GEOLOGY
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Application of geologic information.
Physical properties of rocks
GEOMORPHOLOGY
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Landforms and landform evolution.
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HISTORICAL GEOLOGY
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PALEONTOLOGY
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MINERALOGY
Ancient life (fossils)
STRATIGRAPHY
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MATTERS AND MINERALS
Succession of strata (layers)
GEOCHRONOLOGY
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Branche
of
geology
that
studies
the
composition, properties, and genesis of minerals.
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Age of earth materials to provide a temporal
MINERALS
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framework.
Building blocks of rocks
N- naturally occurring
I- inorganic
Mines and Geosciences Bureau (MGB)
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D- definite chemical composition
Gumagawa ng mga susceptibility maps
O- orderly crystalline structure
H- homogeneously solid
GEOSCIENCES SUBDISCIPLINES
HOW MINERALS ARE FORMED
1. From sodium and chlorine ions
2. Basic building block of the mineral halite.
3. Collection of basic building blocks (crystal)
4. Intergrown crystals of the mineral halite.
REVIEW ON CHEMISTRY
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ATOM
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THE ORIGIN OF THE EARTH
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CATASTROPHISM
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Unknown causes that no longer operate.
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Proposed by Baron Georges Cuvier.
particle
that
cannot
be
PROTON
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Positively charged particles.
NEUTRON
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young).
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smallest
chemically split.
Earth landscapes are shaped by sudden and
often worldwide great catastrophes (Earth is
The
A particle with no charge.
ELECTRON
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Negatively charged particle surrounding the
nucleus.
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UNIFORMITARIANISM
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NUCLEUS
Physical, chemical and biological laws that
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The central part of an atom.
operate today also operated in the geologic
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Composed of neutrons and electrons.
past.
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Small force + time = FORCE
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To understand the past, we look at the
present and relate the two.
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James Hutton
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ATOMIC NUMBER
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Refers to the number of protons in an atom.
ELEMENT
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Refers to the group of atoms of the same
number of protons.
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ATOMIC MASS NUMBER
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Mass of a particular atom.
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No. of Protons + No. of Neutrons
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Atoms of the same element with different
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Very powerful chemical bond
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low melting and boiling points, and cannot
atomic mass numbers.
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Contain nuclei that do not tend to change
spontaneously.
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conduct electricity due to lack of free
STABLE ISOTOPE
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electrons.
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ions.
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ELECTRON CLOUD
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points.
A principal orbit where an electron revolves
PHYSICAL PROPERTIES
OF MINERALS
around the nucleus.
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VALENCE ELECTRON
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Refers to the electron/s on the outermost
shell.
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CHEMICAL BOND
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OPTICAL PROPERTIES
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The results of bonding two or more atoms.
characteristics
of
The use of color as a means of identification
IMPURITIES refers to the element that are
not part of the original compound of the
OCTET RULE
mineral.
Atoms tend to gain, lose, or share electrons
until they are surrounded by eight valence
conspicuous
is often ambiguous or misleading.
CHEMICAL COMPOUND
○
Most
minerals.
minerals, and the rocks.
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COLOR
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The force or mechanism that holds two or
more atoms together to form crystals, then
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conducts electricity and heat, is malleable
and ductile, and has high melting and boiling
A region where electrons move.
PRINCIPAL SHELLS
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The collective sharing of the sea of valence
electrons between positively charged metal
Have a potential to undergo radioactive
decay.
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METALLIC BONDING
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UNSTABLE ISOTOPE
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formed by equal sharing of electrons from
both participating atoms.
ISOTOPE
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COVALENT BONDING
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LUSTER
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electrons.
The appearance of quality of light reflected
from the surface of a mineral.
TYPES OF CHEMICAL BONDING
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Metallic
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Submetallic
Formed by attraction of two atoms with
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Vitreous
opposite charges.
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Dull/Earth
formed between metals and nonmetals, is
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Pearly
strong, crystalline, and solid, melting at high
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Silky
temperatures,
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Greasy
IONIC BONDING
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conductive in water, and
insulators in solid states.
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STREAK
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Color of a mineral in powdered form.
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Help distinguish between minerals with
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metallic and nonmetallic luster.
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Metallic minerals have a dense, dark streak.
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Non-metallic minerals have a light-colored streak.
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Opaque
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Translucent
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Transparent
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Defines the mass per unit volume of
a mineral.
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SPECIFIC GRAVITY
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Describe the density of a mineral.
SENSORY PROPERTIES
Taste
Refers to the common characteristics of the
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Feels
shape of a crystal or aggregate of crystals.
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Smell
MAGNETISM
TENACITY
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DENSITY
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MINERAL STRENGTH
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MINERAL MASS
HABIT
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Refers to the tendency of a mineral to break
along planes of weak bonding.
The ability of a mineral to transmit light.
CRYSTAL SHAPE
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DIAPHANEITY
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CLEAVAGE
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Refers to the strength of a mineral or its
Ability of a mineral to be attracted in a
magnet.
resistance to breaking or deforming
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Brittle
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Malleable
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Sectile
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Elastic
HARDNESS
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DOUBLE REFRACTION
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image when light is transmitted.
EFFERVESCENCE
Measures the resistance of a mineral to
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abrasion or scratching.
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Ability of a mineral to produce a double
Ability of a mineral to fizz when an acid is
placed.
Mohs Hardness Scale: A relative hardness
scale which consists of 10 minerals arranged
MINERAL GROUPS
in order from softest (1) to hardest (10).
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SILICATES
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Rock-forming minerals
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Composed of silicon and oxygen
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Tetrahedron- shaped bond (a pyramid shape
with four identical faces.
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NON-SILICATES
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Economic minerals
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Minerals used for construction
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Other minerals.
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SILICATE STRUCTURE
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Independent tetrahedra
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Single chain
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Double chain
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Sheet structure
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Three- dimension framework
IMPORTANT NON SILICATE
MINERALS
COMMON SILICATE MINERALS
ROCKS AND THE
ROCK CYCLE
ROCK: AGGREGATE OF MINERALS
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ROCK
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The most common and abundant material on
Earth.
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Composed
of
smaller
crystals
called
minerals.
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The
grains
or
crystals
may
be
microscopically small or easily seen with an
unaided eye.
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SEDIMENTARY ROCK
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Classic in texture
IGNEOUS ROCK
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Crystalline texture
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Made of mineral crystal that are interlocking
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BASIC CHARACTERISTICS
OF ROCKS
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(coarse grained).
Pag sa surface ng cool ang crystal ay wala
TEXTURE
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interlock sila at makabuo ng intrusive igneous rocks
silang time mag form ng larger version nila (rapid
Coarse- grained or fine grained?
cooling) creating fine-grained igneous rocks
MINERAL COMPOSITION
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What are the minerals present?
IGNEOUS ROCK TEXTURE
A rock’s mineral composition and texture, in
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turn, reflect the geologic processes that created it.
This
understanding
has
many
practical
applications, as in the search for energy and
mineral
resources
and
the
solution
of
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environmental and engineering problems.
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BASALT
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Rich in dark minerals.
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Rapid cooling of molten rocks at Earth’s
surface
is
responsible
for
the
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rock’s
microscopically small crystals.
IGNEOUS ROCKS
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“Ignis”- latin for fire
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Forms when a molten rock solidifies at the
(extrusive
igneous
rocks)
or
beneath the surface (intrusive igneous
rocks)
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Coarse-grained (>1mm)
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Granite
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intrusive
APHANITIC TEXTURE
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Fine-grained (<1mm)
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Rhyolite
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Extrusive
PORPHYRITIC TEXTURE
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Made up of coarse and fine grains
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Phenocrysts- coarse grains
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Groundmass- fine grains
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Andesite
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Formed sa ilalim ng lupa pero sa labas nag
GLASSY TEXTURE
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No crystals, just glass
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Obsidian
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Formed by very rapid cooling
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Not a mineral
MAGMA
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Molten rock in liquid state
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When magma crystallizes at depth, intrusive
igneous rocks form.
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LAVA
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COMPOSITION OF
IGNEOUS ROCKS
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When magma solidifies on Earth’s surface,
extrusive rocks form.
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cool down
IGNEOUS ROCKS
surface
PHANERITIC TEXTURE
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Molten rock that breaks through the Earth’s
surface.
Pag sa ilalim ng surface ng earth nag cool ang
crystal ay unti-unti itong lalaki hanggang sa mag
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FELSIC
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Light colored
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60% Silica
INTERMEDIATE
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Salt and pepper color (gray)
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55-65% Silica
MAFIC
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Dark colored
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ULTRAMAFIC
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<45% Silica
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Green to black
3. Magsesetle sila sa ilalim ng body of water.
4. The rocks in the bottom of a body of water,
they will bear the pressure of the water and
become compacted and some cementation
Lesser the silica the lighter the rock
happens from natural cements.
Olivine ang nagpapagreen sa rocks
IDENTIFYING SEDIMENTARY
ROCKS
Ultramafic ang mga rocks sa mantle
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DETRITAL SEDIMENTARY ROCKS
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Composed of a clasts of mineral and rock
fragments
SEDIMENTARY ROCKS
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SEDIMENTARY ROCKS
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“Sedimentum”- latin word for settling
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Rock fragments settle at the bottom of the
sea (main characteristics of sedimentary
rocks)
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Rocks formed because of settling.
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Consists of particles derived from weathering
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other rocks.
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Weathering means the breaking down of
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rocks.
Could be igneous, metamorphic, or other
CHEMICAL SEDIMENTARY ROCKS
Precipitation from solution waters
ORGANIC SEDIMENTARY ROCKS
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Best example is coal.
sedimentary rocks.
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Rock fragments that are cemented together.
Limestone- formed in caves
Coquina- formed from loosely cementation of shell
HOW SEDIMENTARY ROCKS FORM
LITHIFICATION
takes
place
during
progressive burial.
CLASTIC is made up of rock fragments
and shell fragments.
Coral reefs- made up of shell and shell fragments
cemented by calcite.
Chalk-
made
up
of
phytoplanktons
1. Weathering
(coccolithophores).
2. Erosion (transporting of rocks) (gumugulong
Coal- made up of buried organic matters
ang mga rock fragments at nag bbreakdown
sila habang nabyahe)
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The mineralogy changes because the rock is
subjected to new conditions, usually elevated
temperature
and
pressures,
which
are
significantly different from those in which it
initially formed.
TYPES OF METAMORPHIC ROCKS
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FOLIATED METAMORPHIC ROCKS
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Usually layered or banded
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Foliation refers to any planar (nearly flat)
arrangement of mineral grains or crystals
within a rock.
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NON-FOLIATED METAMORPHIC ROCKS
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Do not develop a layered or banded
appearance.
○
Small crystals just enlarge because of heat.
METAMORPHIC ROCKS
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METAMORPHIC ROCKS
○ “Meta”- greek word for after, “morph”- greek
word for form
○ Parent rock- original rock
○ When the parent rock is deformed (pressure &
temperature), metamorphic rock is formed.
○ Metamorphic
rock
is
formed
from
deformation of rock.
○ Schist
○ Small crystal rocks later on recrystallizes
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METAMORPHISM
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A process that transforms the mineralogy,
texture and sometimes chemical composition
of the parent rock.
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ROCK CYCLE
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HISTORICAL GEOLOGY
ROCK CYCLE
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Allows
us
to
view
many
of
the
interrelationships among different parts of the
Earth system.
○
Helps us understand the origin of igneous,
sedimentary, and metamorphic rocks.
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Paleontology
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Stratigraphy
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Geochronology
PHYSICAL PROPERTIES OF MINERALS
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Optical properties
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Crystal shape
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Mineral strength
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Mineral mass
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Sensory properties
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Magnetism
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Double Refraction
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Effervescence
OPTICAL PROPERTIES OF A MINERAL
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Color
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Luster
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Streak
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Diaphaneity
CRYSTAL HABIT OF A MINERAL
ENUMERATIONS
PHYSICAL GEOLOGY
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Volcanology
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Seismology
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Environmental geology
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Engineering geology
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Economic geology
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Mineralogy
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Petrology
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Geochemistry
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Geophysics
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Geomorphology
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Equant
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Tabular
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Platy
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Prismatic or columnar
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Bladed
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Acicular
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Capillary or filiform
MINERAL STRENGTH
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Tenacity
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Hardness
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Cleavage
MINERAL MASS
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Density
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Specific Gravity
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MINERAL GROUPS
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Silicates
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Non- Silicates
BASIC CHARACTERISTICS OF ROCKS
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Texture
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Mineral composition
MAJOR GROUPS OF ROCKS
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Igneous rocks
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Sedimentary rocks
IGNEOUS ROCK TEXTURE
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Phaneritic texture
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Aphanitic texture
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Porphyritic texture
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Glassy texture
COMPOSITION OF IGNEOUS ROCKS
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Felsic
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Intermediate
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Mafic
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Ultramafic
IDENTIFYING SEDIMENTARY ROCKS
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Detrital sedimentary rock
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Chemical sedimentary rock
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Organic sedimentary rock
AGENTS OF METAMORPHIC ROCKS
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Heat
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Pressure
TYPES OF METAMORPHIC ROCKS
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Foliated metamorphic rocks
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Non-foliated metamorphic rocks
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