Term
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Definition
Rocks deep in the crust and upper
mantle reach high enough
temperatures to melt |
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Term
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Definition
Formed from magma ascending from deep
in the crust and upper mantle. |
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Term
Magmas that do not make it to the
surface reside in |
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Definition
chambers for long
periods of time (thousands of years) |
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Term
These deep-seated magmas,
insulated by |
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Definition
surrounding crust, cool
very slowly
As a result, large crystals for |
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Term
| The resulting igneous rock is |
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Definition
coarsely crystalline.
These rocks are termed plutonic or
intrusive |
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Term
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Definition
Cool Slowly at Depth. Large
Crystals (Phaneritic |
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Term
Some magmas make it to the surface
of the Earth: |
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Definition
Form lava flows if fluid and gas-poor
– If viscous and rich in dissolved gases,
magmas erupt explosively to form
volcanic ash and glass |
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Term
Lavas on the surface cool quickly
and crystals have little time to grow,
so the rocks are |
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Definition
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Term
| Extrusive Igneous Rocks Cool Quickly: |
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Definition
| Minerals in Rocks Are Small To Non-Existent |
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Term
|
Definition
are
large, irregular
intrusions
crystallized
deep within the
crust |
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Term
|
Definition
tabular
intrusions that
cut across
layering in the
country rock
(discordant) |
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Term
|
Definition
tabular
intrusions
that parallel
the layering
in country
rocks
(concordant |
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Term
| Classification of Igneous Rocks |
|
Definition
Based on composition and mineral
sizes |
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Term
|
Definition
– Felsic >65%
– Intermediate 52 to 65%
– Mafic 45 to 52%
– Ultramafic < 45% |
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Term
| Felsic Igneous Rocks (> 65% Si |
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Definition
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Term
|
Definition
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Term
|
Definition
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Term
Intermediate Igneous Rocks
(52 – 65 % SiO2) |
|
Definition
Compositionally between
felsic and mafic igneous
rocks |
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Term
|
Definition
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Term
|
Definition
|
|
Term
Mafic Igneous Rocks
(45 – 52 % SiO2) |
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Definition
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Term
|
Definition
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Term
|
Definition
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Term
Ultramafic Igneous Rocks
(<45 % SiO2) |
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Definition
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Term
Coarsely crystalline
common |
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Definition
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Term
| Viscosity and Volcanic Eruptions |
|
Definition
A small fraction of magma reaches the
surface and erupts |
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Term
|
Definition
| Eruptions are mild and lava flows easily |
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Term
High silica magmas have high viscosity
(sticky) and retain their gases |
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Definition
High silica, gas rich magmas erupt
explosively |
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Term
|
Definition
Result from viscous, gas-rich magma of
intermediate to high silica content |
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Term
Explosive volcanic eruptions erupt broken
pieces of rock, glass and mineral grains into
the air as a giant column: |
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Definition
Pyroclasts (solid particles) rain down from the sky
– Accumulate on the ground as layers of loose
material such as volcanic ash
– Particles eventually cement together to form
pyroclastic rocks such as tuff or volcanic breccia |
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Term
| Weathering Forms Sediment |
|
Definition
Weathering at the surface by solid
earth interactions with the hydrosphere
and atmosphere breaks down rocks to
form sediment: |
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Term
| Products of weathering include |
|
Definition
– Rock fragments from mechanical
weathering
– Clay minerals and/or iron oxide as
products of chemical weathering
– Dissolved ions into solution |
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Term
|
Definition
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Term
|
Definition
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|
Term
Detrital Sediments
Formed From |
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Definition
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|
Term
Minerals most resistant to weathering are likely
to end up as sediment: |
|
Definition
– Quartz
– Hematite (iron oxide); A product of oxidation
– Clays (products of hydrolysis of silicate minerals)
– K- and Na-rich feldspar (dry climates |
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|
Term
Minerals most susceptible (vulnerable) to
weathering and quickly destroyed are relatively
rare in detrital sediment |
|
Definition
Fe/Mg silicates (olivine, pyroxene and amphibole)
– Halite (soluble in water)
– Calcite (soluble in weakly acidic water) |
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Term
| What Are Sedimentary Rocks? |
|
Definition
Sedimentary rocks form from the products of
weathering |
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Term
| Contain evidence of past environments |
|
Definition
Provide information about sediment transport
– Often contain fossil |
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Term
|
Definition
Detrital (Clastic
Chemical/Biochemical
Organic: |
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Term
|
Definition
Composed of particles of
pre-existing rocks |
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Term
|
Definition
Precipitated from
water, sometimes with the aid of marine
organisms |
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Term
|
Definition
Composed mostly of the remains of
plants and animals |
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Term
|
Definition
A geographic setting where sediment
accumulates |
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Term
Determines the nature of the sediments
that accumulate (composition, grain sizes,
sedimentary structures, etc.) |
|
Definition
Sediment may ultimately be buried and
cemented into a sedimentary rock |
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Term
Laminated
shale and
sandstone
on shelf |
|
Definition
•Mud and ooze
•Sand & gravel in
submarine fans |
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Term
Detrital (clastic) sedimentary rocks
form from |
|
Definition
particles of pre-existing
rocks |
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Term
Detrital sedimentary rocks classified
by |
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Definition
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Term
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Definition
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Term
|
Definition
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Term
|
Definition
| siltstone, mudstone, and shale |
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Term
Chemical and Biochemical
Sedimentary Rocks |
|
Definition
The dissolved ions from weathering are
precipitated from water (often
seawater) by chemical and biochemical
reactions to form chemical and
biochemical sedimentary rocks |
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Term
Chemical and biochemical sedimentary rocks
classified by composition |
|
Definition
Limestone
Chalk
Doloston
Chert
Evaporites
Coal |
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Term
|
Definition
(carbonate rock composed of calcite with
or without fossil shells) |
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Term
|
Definition
(carbonate rock composed of microscopic
shells) |
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Term
|
Definition
(Mg-rich carbonate rock composed of
dolomite) |
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Term
|
Definition
| (siliceous rock composed of silica) |
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Term
|
Definition
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Term
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Definition
| (formed from burial of organic matter) |
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Term
|
Definition
Caves as travertine
Warm shallow seas
Coral reefs |
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Term
| Fine-Grained Clastic Rocks |
|
Definition
Wind
Floodplain
Former lake beds |
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Term
|
Definition
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Term
|
Definition
Shorelines
and Offshore Environments |
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Term
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Definition
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Term
|
Definition
near steep mountain
debris flow |
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Term
|
Definition
| limestone, dolostone in fossils and stuff |
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Term
|
Definition
carbonate
sedimentary rock
composed of
microscopic shells of
marine fossils |
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Term
|
Definition
Dense Rock Composed of
Microcrystalline Quartz |
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Term
| Evaporites Precipitate From |
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Definition
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Term
| Coal is the end product of |
|
Definition
large amounts of plant
material, buried for
millions of years |
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Term
|
Definition
Rocks can be altered if subjected to
higher Temperatures, greater
Pressures and stronger Forces
– Original minerals can recrystallize and
change to new minerals
– Rock texture can change dramatically |
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Term
|
Definition
| High temperatures & pressures over large areas |
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Term
Contact
metamorphism
of country rock |
|
Definition
margins of a
magmatic
intrusion
produces a zone
of hightemperature
alteration
called an
aureole |
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|
Term
Hydrothermal Metamorphism Results From
Reactions Between |
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Definition
|
|
Term
Movement along fault zone
fractures, pulverizes and
shears rock |
|
Definition
Produces fault breccia
near surface and mylonite
at deeper levels
Dynamic
Metamorphism Is
Confined To A Fault
Zone |
|
|
Term
Metamorphic rocks are subdivided
into two broad categories |
|
Definition
Foliated rocks exhibit preferential
alignment of platy minerals and/or other
features in a common direction
– Non-foliated rocks do not exhibit this
preferential alignment |
|
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Term
|
Definition
Low grade
metamorphism (200-
300 oC)
– Minerals include
chlorite, muscovite
mica, quartz, and
feldspar
– Minerals too small to
be seen by naked eye
– Exhibits slaty cleavage |
|
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Term
|
Definition
Upper low-grade
metamorphism
– Mica flakes have
grown larger,
resulting in an
increase in luster
– Most minerals still
too small to be seen
by naked eye |
|
|
Term
|
Definition
Upper low-grade to medium
grade metamorphism (400-
600 oC)
– Increased sizes of minerals
make them visible to naked
eye
– Appearance of garnet,
biotite and staurolite while
chlorite disappears
– Alignment of platy micas
(foliation) clearly visible |
|
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Term
|
Definition
– High grade
metamorphism (600-700
oC)
– Possible appearance of
sillimanite
– Light-colored minerals
(quartz and feldspar)
separate from dark
minerals (biotite micas
and hornblende) as
bands, lenses and streaks |
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|
Term
Regional Metamorphism Of Shale Associated
with |
|
Definition
|
|
Term
| High-Temperature Metamorphism |
|
Definition
Metamorphism
reaches a
temperature (>700o
C) where rock begins
to melt
– The softened rock
becomes highly
contorted and
deformed under
pressure |
|
|
Term
Non-Foliated Metamorphic
Rocks |
|
Definition
No preferential alignment of minerals or
other features |
|
|
Term
Some types of metamorphism lack the
conditions for forming foliated textures |
|
Definition
Contact Metamorphism
– Hydrothermal Metamorphism
– Metamorphism of rocks without platy
minerals |
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Term
Quartzite Forms
From The
Metamorphism |
|
Definition
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Term
|
Definition
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Term
|
Definition
Low-grade
Metamorphism Of Basalt |
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Term
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Definition
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Term
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Definition
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Definition
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Definition
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