Classifying rocks
3 types of rocks are
igneous, metamorphic, sedimentary
magma and lava, cools to form
igneous
what do erosion and weathering have in common?
wind, water, gravity
what is relative time
sequence of events but not the exact time
tiny pieces of rock are called what
sediments
how is metamorphic rock formed?
heat and pressure
true or false, rocks can change from one type to another
True
Difference between weathering and erosion
erosion - transport
weathering - break down of rocks
what is absolute time
the exact time something took place
what is syncline
where is sinks down into the earth
igneous rocks are categorised as _______ or ________ depending on where they are cooled
intrusive
extrusive
metamorphic rock melts to become what?
magma
Difference between erosion and deposition
erosion - movement/ transport
Deposition - where sediments settle
what is the law of superposition
states that the older beds are covered by younger beds.
the youngest beds are on the top
the oldest beds are down the bottom
Explain the different between extrusive and intrusive, noting the size of the crystals for each
extrusive - cooled quicker on the outside, smaller crystals
intrusive - cool slower, inside of earth, larger crystals
difference between sedimentary and igneous rocks (how they are formed)
sedimentary - small sediments build up over time, are compacted and cemented down forming sedimentary rocks
igneous - is the cooling of magma or lava on the inside or outside of the earth
what does igneous have to go through to become sedimentary rock
weathering and erosion
then compaction and cementation
what are the two types of weathering, explain the differences
chemical - dissolved or changed minerals in rocks to become other minerals
physical - breaking larger rocks into smaller pieces, but minerals do not change
is an igneous intrusion younger or older than the layered beds around it
younger
what is the law of horizontality
all rock layers initially form in horizontal layers
Once igneous or sedimentary, gone through _________ to be come ______________ rock
metamorphosis
metamorphic
how does sedimentary rock become igneous rock?
heat and pressure, leading it to become metamorphic, then melting to become lava, then cooling to become igneous rock
what are some 4 methods of erosion
mud slide
winds
run off
glacier
water (streams)
living organisms
humans
what is a fault, explain if it is younger or older
break in the earths crust cause by geologic forces.
it is always younger than the layer of rock around it
what are the 5 steps of the formation of sedimentary rocks, in order
weathering, erosion, deposition, compaction, cementation