Rock cycle Flashcards
Definition of the rock cycle
cycle of processes that occur in the Earth’s crust to
create and destroy rocks.
Definition of a rock
a naturally occurring solid mass or aggregate of minerals or
mineraloid matter
Definition of a mineral
‘naturally occurring, inorganic crystalline solids that have a
definite chemical composition. Minerals have characteristic physical
properties’
How are sediment generated
Sediments are generated through weathering
and erosion
How does the lithification of sedimentary rocks occur
- Compaction and cementation
- Sedimentary rock formation
Define a igneous rock
An igneous rock is a rock that has formed
by the cooling and crystallization
(solidification) of molten rock.
________ originates deep
within the Earth’s
lithosphere / upper
mantle due to the melting
of rock and associated
minerals.
________ is the name given to
molten rock when it
reaches the Earth’s
surface from volcanic
activity.
magma
lava
igneous rocks are typically classified by
- rock texture - size of crystals or grains in
the rock, called grain size - composition - type of minerals present
- colour- type of minerals present
Rock texture - mineral crystal size can be affected by
A) the rate of cooling,
B) the original temperature of the
magma, and
C) the crystallization temperature of
the mineral the crystal is composed
of.
Intrusive igneous rocks:
If a large volume of magma cools slowly within the
lithosphere, the crystallized rock is known as a _________
igneous rock or an intrusive igneous rock
Magma cools _______ within the lithosphere, permitting the
growth of mineral crystals to form intrusive igneous rocks
Plutonic
slowly
What does phaneritic texture mean
Visible grains
1 to 5mm
interlocking crystalline texture
Plutonic rocks posses a ________ _________
Phaneritic texture
Extrusive igneous rocks:
Igneous rocks that reach the
Earth’s surface cool, solidify, and
crystallize relatively _______ (e.g.,
at a rate of minutes to months)
and are called extrusive igneous
rocks
quickly
Aphanitic meaning
fine grained texture. crystals are too small to see with the naked eye
extrusive rocks have a ________ texture
aphanitic
What is vesicular texture
If the solidifying
igneous rock contains
gas (e.g., sulfur and
carbon dioxide),
bubbles of entrapped
gas may form holes as
the rock solidifies.
How does volcanic glass occur
rapid cooling, or chilling, prevents the
crystallization of minerals
very rapid cooling forms a natural glass
known as
obsidian
frothed natural glass as a result of
excessive gas in the magma creates
_______ when it cool
pumice
Define equigranular
If all mineral crystals are approximately the same size,
use the term
Define porphyritic rock texture
If the rock has large mineral grains surrounded by a
finer-grained groundmass (i.e., the majority of finer
mineral grains forming the bulk of the rock)
Felsic rocks contain what minerals
Potassium feldspar
Quartz
Plagioclase feldspar(Na-rich)
Biotite
Amphibole
Intermediate rocks contain what minerals
Mainly: Plagioclase feldspar, pyroxene
Smaller amounts of potassium feldspar, quartz, biotite, and amphibole
Mafic rocks contain which minerals
Plagioclase feldspar, pyroxene and a small bit of olivine