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Unit 5 Planet Earth Vocabulary
Topic 1 Minerals
Rock- a natural material composed of one or more minerals
Minerals –an inorganic naturally occurring solid material that can be an
element or compound
Crust- the thin outermost layer of Earth
Element- a type of pure substance that cannot be broken down into
simpler parts by chemical means and that has a unique set of properties
Crystals – the building block of minerals; crystals occur naturally and
have straight edges, flat sides, and regular angles.
Lustre- the light reflecting properties or “shininess” of minerals.
Streak – the colour of a mineral in powdered form useful for identifying
the mineral.
Cleavage – the characteristic of a mineral whereby it splits along smooth
flat planes. The type of cleavage the mineral has is useful for identifying
it.
Fracture – the breaking of a mineral split into jagged, rough pieces
Topic 2 Rocks and the Rock Cycle
Igneous rock- [IG-nee-uhs] the type of rock that is formed by the
solidification of hot magma; it is defined as either intrusive or extrusive
(361)
Magma- melted rock, formed under Earth's crust by high temperature
and pressure; magma occasionally escapes to Earth's surface as lava (361)
Intrusive rock- the type of igneous rock formed when magma cools and
solidifies below Earth's crust (361)
Lava- the term used for magma when it breaks through Earth's crust, as
in a volcanic eruption (361)
Extrusive rock- the type of igneous rock formed when magma (lava)
cools and solidifies above Earth's crust (361)
Sedimentary rock - the most common type-of rock on Earth's surface;
formed by the compacting of sediment (loose materials, such as minerals
and organic remains) (364)
Sediment - loose material such as bits of rock, "minerals, and plant and
animal remains (364)
Stratification- the arrangement of sedimentary rock in visible layers (364)
Compaction - the process by which sedimentary rock is formed from
sediment, through the weight and pressure of water and other sediment
Cementation- a process by which particles are held together by another
material (365)
Metamorphic rock - a type of rock made when high pressure and heat act
on another type of rock and change it into a new form (366)
Parent rock - the original rock that was acted on by high pressure and
heat to form a metamorphic rock (366)
Rock cycle - the naturally occurring process in which rocks continue to
change form over long periods of time (3 68)
Compost- the part of soil composed of dead plant matter (371)
Humus - humus [HYOO-muhs] the dark-coloured part of soil that is rich in
nutrients, such as nitrogen, phosphorus, potassium, and sulphur (150,
371)
Fertile- of soil, containing the nutrients needed for plant growth (371)
Soil profile - a description of the characteristics of the different layers that
make up a particular soil (3 72)
Topsoil the topmost layer of soil, which is dark-coloured and rich in
humus (150, 372)
Leaching -the process by which materials from soil are dissolved and
carried away by water (3 72)
Topic 3 Erosion (read page 373)
Erosion - the process of moving soil and rock from one place to another;
mechanical weathering caused by the effects of wind and/or water (373)
Weathering (mechanical, chemical, and biological weathering) the
process in which rocks are broken down and sediment is formed by
mechanical, chemical, or biological means
Frost wedging - a process of mechanical weathering that occurs when
water goes through a cycle of freezing and thawing; the water expands
and contracts in the cracks of a rock, eventually breaking the rock apart
Sedimentation- the process in which eroded material is deposited and
built up (373)
Abrasion - the wearing down of rocks by wind, ice, waves, and running
water (377)
Topic 4 The Moving Crust
Mantle the middle layer of Earth, located between the crust and the core,
and made of rock
Continental drift - a theory about Earth's structure; according to this
theory, the continents have slowly changed their positions over time; the
slow movement of continents (384)
Sonar - (sound navigation and ranging) a technology that bounces sound
waves off an object to determine its distance from the source of the
waves (387)
Sea floor spreading -the process in which an ocean floor slowly increases
in size over time because of the formation of new igneous rock along a
fault (388)
secondary (S) waves- the second fastest moving of the three types of
seismic waves that are produced by an earthquake, originating from its
focus; can pass through solids but not liquids or gases (398)
Plates- one of the large sections into which Earth's crust is divided (390)
Theory of plate tectonics -theory suggesting the lithosphere is divided
into plates that interact with each other (390)
Converging plates - two or more plates colliding (390)
Diverging plates - two or more plates moving away from each other (390)
Convection currents continuous circulation of a fluid (either a liquid or a
gas), in which thermal energy is transferred from hotter, less dense fluid
to colder, more dense fluid (230, 392)
Subduction zones a place on Earth's crust where high pressure pushes one
very large piece of rock below another; earthquakes are often formed in
subduction zones(393)
Topic 5 Earthquakes
Seismograph- a sensitive machine that is attached to bedrock in order to
measure the strength of earthquakes
Bedrock- The part of earth's crust that is made up of solid rock, lying
beneath the soil and looser rocks
Richter scale- a scale on which the magnitude or strength, of an
earthquake is measured.
primary (P) waves-the fastest moving of the three types of seismic waves
that are produced by an earthquake, originated from it's focus; can pass
through solids, liquids, and gasses.
Secondary (S} waves- the second fastest moving of the three types of
seismic waves that are produced by an earthquake, originating from it's
focus; can pass through solids, but not liquids or gasses.
Surface waves- the slowest moving of the three types of seismic waves
that are produced by an earthquake, originating from it's epicentre:
surface waves -do the most damage of the three types of waves.
Focus
Epicentre
Fault- an area where two very large rock surfaces move against each
other.
Topic 6 Volcanoes
Vent- an opening in earth's crust through which magma can escape,
forming lava.
Dormant- a volcano, a stage when eruption is occurring
Ring of fire- an area of volcanoes around the Pacific Ocean.
Topic 7 Mountains
Anticline- an up fold of rock layers in sedimentary rock
Syncline- a downfold of rock layers in sedimentary rock
Thrust Faulting- low angle faulting of rock.
Fault block mountains-mountains formed by the process of thrust
faulting
Complex mountains-mountains that are formed by the combined process
of folding and faulting
Topic 8 Fossils
Petrified -a rock like substance formed when water penetrated dead
organic matter, and deposits dissolved mineral matter
Carbonaceous film –a type of fossil found in sedimentary rock and
organic material – its compressed leaving a thin carbon film
Mould -a type of fossil in which the hard parts of an organism have
dissolved leaving a cavity in the rock
Cast –a type of fossil in which sediments or materials have filled a mould
and hardened into rock.
Topic 9 Geologic time
Principle of superposition- a geographical theory: according to this
theory, in undisturbed layers of rock. the oldest layers will be on the
bottom, and the youngest layers will be on
Strata- layers of sedimentary rock
Relative dating- determining the order in which geological events accored
and the relative age of rocksbv thei posistion in rock layer
Index fossils- a type of fossil that cam be used to determine the age of the
material in which it was found
Half life- the amount of time that the amound odfthat a given amount of
radioactive substances takes to be reduces one half
Radiometric dating-The process of determining the age of a geological
specimen by measuring the relative amounts of radiation
Radio carbon dating- a method used to determine the age of organic
remains by measuring the relative amount of radio active carbon found in
the remains.
Geologic Time Scale- it is a division of Earth’s history into smaller units
based on the appearances of different life forms.
Eons- the largest division of time on the geological scale.
Eras-one of the four longest subdivisions of in the history of the earth.
Periods- on the geological time scale a subdevisional of an era.
Precambrian- the first of the four eras on the geologic time scale.
Rodinia- the name of the earliest super continent thought to have broken
apart approximately 750 million years ago: Rodinia included all the large
land masses.
Paleozoic era- the second era on the geological time scale the ara in which
the first plants and animals appeared
Mesozoic era- the third era on the geological time scale the era in which
dinosaurs were the dominant life form on earth
Cenozoic era- the fourth and current era on the geological time scale the
era in which humans evolved,
Pangea- the name of the second super continent thought to have existed
approximately 350 million years ago: Pangea included all the present
continents
Laurasia- the northern part of the super continental Pangea which split
off approximately 200 million years ago
Gondwanaland- the southern part of the super continent Pangea which
split off approximately 200 million years ago
Topic 10 Fossil Fuels
Petroleum- a type of oil found in rock formation in earths crust
petroleum is refined into products such as gasoline or jet fuel.
Fossil fuels- fuels made of decomposed plants and other organizums the
have been hardened or fossilized: fossil fuels take millions of years to
develop: examples of fossil fuels include coal oil and natural gas,
Bitumen- a heavy almost solid form of petroleum some bitumen depo
sites are found near the surface of earth and can be mined or heated and
pumped to the surface