EXAM 2 Igneous Rocks, EXAM 2 Sedimentary Rocks, EXAM 2 Metamorphic Rock
magma
BENEATH Earth's surface, often generated in upper asthenosphere and lithosphere in magma chambers
lava
ON Earth's surface, composed of silicate minerals
What is the difference between the formations of chalk versus chert?
They are made of different source materials.
A porphyritic texture where large crystals are embedded in a matrix of small crystal may form when ________.
a magma that has partially crystallized slowly moves to a different location where it then cools rapidly
rock
a solid aggregate of one or more minerals, or mineral material
confining pressure
applies forces equally in all directions
Most commonly, felsic igneous rocks ________________.
are lighter in color than mafic rocks
plutons
blob-shapes intrusions that solidify from magma chambers
burial metamorphism
bottom of thick sedimentary rock piles
mechanical weathering
breaking apart of rock
erosion
broken fragments are removed
Igneous rock is formed ________.
by crystallization of magma
Precipitation of gypsum due to evaporation of seawater produces which kind of sedimentary rock?
chemical
What type of sediments are found in lake bottoms?
clay/mud
how is sediment turned into solid rock?
compaction and cementation
sedimentary rock
compaction and cementation of sediments
alluvial fan
conglomerate and arkose
As compared to coarse-grained igneous rocks, fine-grained igneous rocks ______________.
cool and solidify more quickly
extrusive rock crystal size?
cool fast/small crystals
intrusive rock crystal size?
cool slowly/large crystals
igneous rocks
cooling of molten rock
shallow marine
coquina
dikes
cut across rock layers
chemical weathering
dissolving of the minerals
composition
felsic, intermediate, mafic, ultramafic
texture
fine(aphanitic), coarse(phaneritic)
When a metamorphic rock exhibits a layered or banded appearance, it is said to exhibit a(n) ________ texture.
foliated
schist, slate, gneiss
foliated metamorphic rocks
clastic rock
formed from fragments of other rocks, coarse/medium/fine grained
slow rate of cooling
forms large crystals
fast rate of cooling
forms small crystals
biochemical rock
fossils, fine and coarse grained
heat comes from?
from magmatic intrusions
schist turns into?
gneiss
playa lake
halite
The primary agent of contact metamorphism is ________.
heat
cause changes?
heat and pressure
contact/thermal metamorphism
heat, pre-existing rock comes into contact w molten lava or magma, recrystallize DOES NOT MELT
Lithification occurs ________.
in the shallow subsurface
ripple marks
indicate a shallow stream or ocean environment
mud cracks
indicate arid environment that was drying out
angularity
individual clasts become more rounded and smoother the further they are transported
phaneritic texture
individual mineral grains can be seen w the naked eye
Compaction and cementation of grains occur during ________.
lithification
sorting
long distance transport sifts grains, and carries smaller ones farther leaving coarser ones behind
sediment
loose materials, such as rock fragments, mineral grains, and the remains of once-living plants and animals, that have been moved by wind, water, ice, or gravity.
Slate is associated with ________ metamorphism.
low grade
"formed by fire" examples
magma and lave
Which of the following minerals is particularly prominent in schist?
mica
deep marine
micrite and fossiliferous limestone
rocks classified according to:
mineral composition, chemical composition, texture, how they were formed
cementation
minerals precipitate between the grains, forming mineral cement
porphyritic texture
mixture of coarse and fine crystals, two-stage cooling (slow then fast)
mafic
more dark minerals (black), Augite
felsic
more light minerals, Quarts or K-Feldspar
regional metamorphism
mountain building, greatest volume of metamorphic rock produced, heat and pressure used
lake
mudstone and shale
delta
mudstone and siltstones
marble and quartzite
non-foliated metamorphic rocks
Non-Foliated Metamorphic Rock
not banded, do not break into layers, massive crystalline, pressure
foliated metamorphic rock
parallel layers of bonds, directed pressure
sills
parallel to rock layers
Every metamorphic rock has a ________ from which it formed.
parent rock
protolith
parent rock, metamorphic rocks hold same chemical composition as parent, mineral makeup determines degree of change
slate turns into?
phyllite
organic rock
plant material, fine grained
An irregular-shaped and blob-like igneous rock body that cooled beneath the surface of Earth is a ________________.
pluton
Which igneous texture is characterized by two distinctively different crystal sizes?
porphyritic
The primary difference between breccia and conglomerate is that conglomerate ________.
possesses more rounded grains than breccia
chemical rock
precipitation/evaporation of water, crystalline
compaction
presses the grains together
Metamorphosed sandstone is known as ________.
quartzite
Coarse-grained granite is most similar in mineral composition to fine-grained ________.
rhyolite
Which of the following changes may occur during metamorphism?
rock becomes more compact, crystals may grow larger, certain minerals may recrystallize
"formed by fire"
rocks formed from molten rock material
plutonic or intrusive rocks
rocks formed inside Earth, phaneritic, several colors **rich in Magnesium and Iron
volcanic or extrusive rocks
rocks formed on the surface, aphanitic(crystals too small to see w naked eye), single color, glassy
intermediate
same amount of dark minerals as light (salt and pepper), Hornblende
phyllite turns into?
schist
A fine-grained clastic sedimentary rock that splits into thin sheets is ________.
shale
Siltstone or mudstone containing marine fossils likely formed in a ________ environment.
shallow-marine
shale turns into?
slate
During metamorphism, the material undergoing deformation remains a ________.
solid
weathering
solid rock is broken down
rock cycle
system that links subsurface processes driven by Earth's internal heat to surface processes driven by solar energy
Intrusive igneous rocks are often coarse-grained because ________.
the slow cooling at depth allows large crystals to grow
Grains become rounded primarily during ________.
transportation
The mineral olivine is characteristic of a ________ magma.
ultramafic
differential pressure
unequal in different directions
batholith
vast composite, intrusive, igneous rock formed by the intrusion of numerous plutons in same region
ultramafic
very dark in color, mostly olivine (green)
If magma or lava cools quickly, the resulting igneous rock will have ________.
very small crystals
If a geologist found preserved mud cracks, he or she could conclude that the environment in which they formed ________.
was once covered in wet mud
metamorphic rock
when a rock changes shape/form
does heat increase in temperature with depth?
yes - geothermal gradient
does pressure increase with depth?
yes - mountain formations
