Science Grade 7 - Unit 5: Planet Earth
what scale is used to identify a mineral's hardness on a scale from 1 to 10
Moh's Hardness Scale
the light-reflecting properties, or shininess of materials
lustre
the color of a mineral in powder form
streak
the identification of a mineral's shape
crystal
how a mineral breaks apart when you drop or break it
breakage
the 2 different types of mineral breakage
• cleavage - smooth, flat
• fracture - rough, jagged
what type of texture is cleavage
smooth and flat
what type of texture is fracture
rough and jagged
the 6 main parts of mineral identification
• hardness
• lustre
• color
• streak
• crystal
• breakage
the arrangement of sedimentary rock in visible layers
stratification
the process by which sedimentary rock is formed from sediment, through the weight and pressure of water and other sediment
compaction
a process by which particles are held together by another material in order to make rock
cementation
a type of rock made when high pressure and heat act on another type of rock and change it into a new form
metamorphic
an example of the 3 stages of making metamorphic rock
shale → slate → sehchish
the 3 main parts of the rock cycle in order
metamorphic → igneous → sedimentary
an abbreviation of the rock cycle (hint: what is said in front of an unwed woman's last name)
M.I.S (metamorphic, igneous, sedimentary)
a description of the characteristics of the different layers that make up a particular soil
soil profile
the break-up or disintegration of rocks caused by physical forces such as wind, water, and gravity
mechanical weathering
the reaction of rock minerals with oxygen, thus changing the mineral composition of the rock. This makes the minerals less resistant to weathering
oxidation
a type of weathering caused by living organisms
biological weathering
what are the 4 layers of the earth listed from center of surface
• inner core
• outer core
• mantle
• crust
what are the 4 layers of the earth listed from surface to center
• crust
• mantle
• outer core
• inner core
who invented the theory about continental drift
Alfred Wegener
continuous circulation of fluid (gases and liquids) in which thermal energy is transferred
convection current
how are different temperatures of energy transferred in a convection current
from hotter, less dense fluid to colder, more dense fluid
a place on the Earth's crust (surface) where high pressure pushes one very large piece of rock below another
subduction zone
where are earthquakes often formed in
subduction zones
rocks frozen in glaciers scrape against the bedrock, making scratches
striations
eroded sediments pushed up in front of or along the sides of glaciers as they move, forming piles
moraines
a boulder or other large rock that has been transported and deposited by a glacier
erratics
what is unique about an erratic rock's physical characteristics because of its location
erratics will have different physical characteristics (appearance) than the other rocks around it because it was not originally formed in the same environment
what type of scientist studies earthquakes
seismologists
what device is used to measure earthquakes
seismograph
what scale is used to measure the strength of an earthquake
Richter scale
the 3 different kinds of seismic waves that occur in an earthquake (in the order of occurrence)
primary (P) → secondary (S) → surface waves
the surface location of an earthquake directly above the focus
epicentre
the place deep in the center of the Earth's crust
the focus
a type of fault that occurs due to tension forces and causes rocks to move down
normal fault
a type of fault that occurs due to compression forces and generally pushes rock upward
reverse fault
a type of fault that occurs due to shear forces. The rocks along these faults usually have bumps or bulges
transform faults or a strike-slip
what is another term for a transform fault
a strike-slip
the name of the famous volcanoe that preserved many things such as people in ash in the year of 1944
Mount Vesuvius
what year did Mount Vesuvius famously erupt
1944
a circle of volcanoes surrounding the pacific ocean
the Ring of Fire
what type of ZONE does the Ring of Fire occur at
subduction zone
a type of mountain formed by folding AND faulting
complex mountains
the hard parts of an organism desolved, leaving a cavity in the rock (fossils)
mould
sediments or minerals have filled a mould and hardened into rock (fossils)
cast
in undisturbed layers of sedimentary rock, the oldest layers are always on the bottom and the youngest layers are always on the top. What principle supports this
Principle of Superposition
layers of sedimentary rock
strata
the amount of time that a given radioactive substance takes to be reduced by one half
half-life
the first 4 billion years that earth existed. The first supercontinent Rodinia was formed
precambrian period
means 'ancient life'. A time period that existed approximately from 590 million to 248 million years ago
paleozoic era
means 'middle life'. A time period that existed approximately from 248 million to 65 million years ago. Dinosaurs roamed the earth during this time
mesozoic era
means 'recent life'. A time period that existed approximately from 65 million years ago to precent day
cenozoic era
oil found in rock formations in the Earth's crust (sedimentary rock)
petroleum
what is petroleum refined into (2 things)
gasoline or jet fuel
another mineral other than petroleum that can be rifined into gasoline and jet fuel
bitumen
the 4 main time periods in order from oldest to most recent (hint: opposite from alphabetical order)
precambrian → paleozoic → mesozoic → cenozoic
the 4 main periods of time in order from most recent to oldest (hint: in alphabetical order)
cenozoic → mesozoic → paleozoic → precambrian