Module 1 Geology
In the three months following the 1991 Mt. Pinatubo eruption, how many lahars occurred?
200
The size of the mineral grains inside of an igneous rock is primarily controlled by
cooling rate of the rock
Horizontal intrusion
sill
Resurgent Dome
magma gasses renters chamber, lifts floor of caldera/ceiling of a magma chamber (often found inside calderas) (secondary post eruption)
Olivine Chemical Formula
(Mg,Fe)2SiO4
Inner Core
Solid, metallic, most dense
Mt. Pinatubo, Phillapines erupted on June 15, 1991. How high was the ash column that ejected from the volcano?
35 km
Our understanding of the Earth's deep interior (mantle & core) comes from (SELECT ALL THAT APPLY)
- areas where mantle rocks have been brought to the surface - meteorites that have fallen to Earth from space - seismic wave profiles of the Earth's interior - presence of a magnetic field surrounding the Earth
How do you form magma?
1. High temp 2. Low pressure 3. High water content
"Year without Summer"
1816, Mt. Tambora in Indonesia, climatic cooling event and volcanic winter
Kilauea volcano located on the big island of Hawaii has been erupting since ______.
1983
How long after the eruption of Mt. Pinatubo did the climatic effect last?
3 years
The current scientific estimate for the age of the Earth is
4.56 Billion years
How many people died in the May 18, 1980 eruption of Mt. St. Helens?
57
The radius of the Earth is approximately
6,371 km
Volcanic Crater
A funnel-shaped depression from which gas, tephra, and lava are ejected. (S-P Crater, AZ)
Anion
A negatively charged ion
Cation
A positively charged ion
Which minerals on Bowen's reaction series might you expect to find in diorite?
Amphiboles, Biotite & Na-rich feldspars (Albite)
Calcite Chemical Formula
CaCO3
Mica has distinct
Cleavage (cuts in sheets)
What are the two cooling features?
Columnar Joints and Pillow Basalts
Who figured out the radius and circumference of the earth?
Eratosthenes
Which of the following silicate minerals contain the highest amount of silica?
Framework
What three igneous rocks are intrusive?
Granite (felsic), Diorite (Intermediate), Gabbro (Mafic)
In professor Nick Zentner's 2-minute geology video on Columbia river flood basalts, the rocks are similar in chemistry to the ______________ volcano and more similar in age to the ________________ volcano.
Hawaiian, Yellowstone
Who figured out the density of the earth?
Henry Cavendish
Who came up with the Principle of Uniformitarianism?
James Hutton
According to Bowen's reaction series, which pink-colored feldspar mineral is most felsic and most stable at the Earth's surface?
K-rich (potassium) feldspar
Which interior Earth layer is the thickest?
Mantle
Double Chain Silicates
Mineral group called amphiboles
Single-Chain Silicates
Mineral group called pyroxenes
Cindercone Volcanoes
More explosive than Hawaii, strombolian eruption style, may eject showers of lava 100 ft in air
Which volcanic eruption has a higher VEI number? (Kilauea, HI) (Soufriere Hills, Montserrat (Caribbean), or (Mt. Pinatubo, Philippines)
Mt. Pinatubo, Phillipines
What is the name of this black glassy mineraloid that breaks along curved surfaces known as conchoidal fracture?
Obsidian
The idea that during Earth's early formation, the densest materials inside the Earth sank to the core and the lighter materials rose to the surface and cooled is attributed to the
Planetary Differentiation Model
What terms explain diorite?
Plutonic, Phaneritic, Intermediate composition.
The 79 AD eruption of Mt. Vesuvius, Italy killed more than 20,000 people in the ancient city of
Pompeii
What three igneous rocks are extrusive?
Rhyolite (felsic), Andesite (intermediate), Basalt (Mafic)
The mineral Quartz has the specific chemical formula
SiO2
Igneous Intrusions
Sill (horizontal intrusion of magma), Dike (vertical intrusion of magma)
Select the proper sequencing order of geologic time periods (from oldest to youngest)
Triassic, Jurassic, Cretaceous
Lava is magma that has reached the Earth's surface.
True
The VEI scale stands for Volcanic Explosivity Index.
True
The phanaritic equivalent of a basalt is a gabbro.
True
Geyser
a natural spring showing intermittent water and steam discharge ("old faithful" Yellowstone)
Mt. St. Helens volcano of the Cascades volcanic mountain range in the Pacific Northwestern US is a stratovolcano that produced __________ on May 18, 1980.
a lateral blast
After the May 18, 1980 eruption of Mt. St. Helens, time-lapse video footage from inside the crater showed what happening?
a lava dome growing
The current scientific estimate of the age of the Earth comes from radiometric age dating of
a meteorite
Hot Spring
a spring that is produced by the emergence of geothermally heated groundwater from the Earth's crust (Grand Prismatic Yellowstone)
Which igneous rock type would you expect to find around Mt. St. Helens & the Cascades stratovolcanoes? (Hint: where the mafic Juan de Fuca oceanic plate subducts beneath the felsic North American continental plate & forms intermediate composition magma)
andesite
A volcanic eruption is an exchange of matter primarily between which two Earth systems?
atmosphere, geosphere (solid earth)
The Hawaiian volcanic islands are made out of the igneous rock ___________.
basalt
Difference between biotite and muscovite?
biotite is intermediate in silica, muscovite high in silica
Xenolith
chunks that don't belong
In 1943, Paracutin, Mexico a ____________________ volcano grew within a week.
cindercone
A mineral has _______________ when it breaks along dimensional (1-D, 2-D, 3-D) planes of atomic weakness.
cleavage
Which layer of the Earth is the least dense?
continental crust
Subduction Zones
convergent plate boundaries, oceanic plate vs. continental plate (Juan de Fuca)
After the June 15, 1991 eruption of Mt. Pinatubo, large amounts of SO2 gas was emitted. This gas combines with H2O vapor to created sulfuric acid aerosols that have a ___________ effect on global climate.
cooling
Columnar Joints
cooling features within lava flow or igneous intrusion formed due to stress as the cooling magma or lava contracts inward (6 sided) (Giant's Causeway-Northern Ireland)
Mafic silicate minerals tend to be _________ in color, while felsic silicate minerals tend to be __________ in color.
dark, light
At divergent plate boundaries, there tends to be volcanoes. Magma is formed at those tectonic locations because of
decompression melting
If a calcite (CaCO3) xenolith, broke off and tumbled in and mixed/melted into a magma chamber, what might that do to the Silica content of the magma?
decrease the Silica content
Vertical Intrusion
dike
The mineral calcite (SELECT TWO):
dissolves & effervesces CO2 gas in an acid and is the primary mineral in the sedimentary rock Limestone.
When two tectonic plates pull apart from one another it is called a ____________ plate boundary.
divergent
Spreading Centers
divergent boundaries where plates are ripping apart (decompression melting)
The mineral Calcite is easily distinguishable because it
effervesces CO2 gas in the presence of an acid
______________ are negatively-charged subatomic particles. that occupy in shells or clouds outside an atom's nucleus.
electrons
Andesite is an igneous rock that is:
extrusive, volcanic, aphanitic, formed from quick-cooling magma, composed of amphiboles, biotite mica & Albite
All hotspot volcanoes are explosive.
false
Jet black obsidian (volcanic glass) is often found near and around the black basaltic volcanic rocks of the Hawaiian islands.
false
Volcanoes always have a conical (upside down ice-cream cone) shape.
false
Water is considered a mineral.
false
Framework Silicates
feldspar and quartz
Generally speaking, if a magma (melt) is high in silica content (>65%), the more _________the magma.
felsic, high viscousity, gas trapping, explosive
The Yellowstone Supervolcano has a magma more______ than Hawaiian volcanoes.
felsic, viscous, explosive
The primary difference between the igneous rocks granite and rhyolite is
grain size (crystals)
The shape of the Earth is a spheroid due to the competition of _______ and ________ forces.
gravitational, centrifugal
Hot Spots
heat from core, Hawaii, and Yellowstone
Hawaii and Yellowstone volcanoes are similar in that they are both___________ volcanoes.
hot spot
Kilauea volcano of the Hawaiian islands is a _________ volcano.
hot spot
Fumaroles
hydrothermal vents - emit steam
A gabbro sill would form
inside the earth (intrusive)
According to Bowen's Reaction Series, olivine is a(n) ________ silicate, that crystallizes _______ in a cooling magma chamber and is _________ at the Earth's surface.
isolated, first, unstable
What is special about volcanic lightning?
it presents horizontally across the sky
A _____________ is a large, mushroom-shaped igneous intrusion.
laccolith
The capital city of Plymouth on the Carribbean island of Montserrat was buried by a volcanic mudslide called a _______.
lahar
Volcanic ash that becomes water-saturated after rainfall events turn the ash into a volcanic mudflow called a
lahar
What hazard? 1985 Armero Tragedy, Columbia, S. America, kills 23,000
lahar
The mineral pyrite (fool's gold) can be easily distinguished from elemental gold (Au) by
leaving a distinctive dark streak across a ceramic streak plate
Relative to a theory, an hypothesis has:
less certainty
In order to be considered to be high in viscousity, what are two things that are required:
low temp and high in silica
According to Bowen's Reaction series, white mica (muscovite) crystallizes from a melt at a(n) _________ temperature compared to black mica (biotite).
lower
A super eruption could produce a climatic event that could ___________ global temperatures by several degrees Celsius and last _____- years.
lower, 4-5
The strongest seismic discontinuity (the speed of seismic waves changes) occurs at the
mantle-outer core boundary
In class we calculated the density (D=M/V) of a small piece of sedimentary sandstone. We measured the mass of the sandstone on a small balance (scale). Next we measured the sample's volume. How did we do that?
measured volume using water displacement method
The lithosphere and asthenosphere are interior layers of the Earth primarily defined on the basis of their
mechanical strength (strong vs. weak)
Sheet Silicates
mineral group called biotites (mica) and muscovites
According to Hutton's Principle of Uniformitarianism:
modern geologic processes occur in much the same manner as they did in the past
Outer Core
molten/liquid, metallic, S-Waves disappear
Stratovolcano
most explosive, concave slopes, Plinian eruption style (extremely violent), pyroclastic flows, form at subduction zones Example: Mt. Fuji
Laccolith
mushroom shaped
Shield Volcanoes
non-explosive, but largest in size Example: Hawaii
Pillow Basalts
only form underwater, lava enters water passively as bulbous bodies of quenched (cooled quickly) forming a glassy skin
An element is defined by the number of _______ in its nucleus
protons
The 1997 eruption of Soufriere Hills, Montserrat of the Carribbean produced a 10km ash cloud and a dense cloud of hot gas, ash & volcanic debris called a ___________.
pyroclastic flow
What hazard? 1902 Mt. Pelee Caribeean, kills 29,000.
pyroclastic flow
What hazard? 79 AD Mt. Vesuvius, Italy kills 1500
pyroclastic flow
Which of the following is a primary(main) hazard of stratovolcanoes?
pyroclastic flows
According to Bowen's Reaction Series, which mineral crystallizes last and is most stable at Earth's surface temperatures & pressures?
quartz
Using sun, shadows & simple math, Greek scientist Eratosthenes, calculated the Earth's_____________.
radius
Which igneous rock was quenched (cooled quickly) & contains the highest amount of silica?
rhyolite
Which is the largest (size) type of volcano?
shield
Crust
silica rich, thinnest, least dense
Mantle
silica-poor, thickest layer
To which of the following groups do most minerals in the Earth's crust belong?
silicates
These miners are looking at crystals of the mineral Gypsum. The most unique identifying characteristic of Gypsum is
softer than a human fingernail
Which group of meteorites is most similar in chemical composition to the mantle?
stony-iron meteorites
A steep, concave-sided cone-shaped volcano is called a __________ volcano.
strato
Souffriere Hills, Montserrat in the Carribbean is a ___________ volcano.
subduction zone
The Cascades volcanic mountain chain of the Pacific Northwest (Washington state, Oregon, northern California) are produced by
subduction zones
The common mineral halite has a distinctive
taste
Kilauea lava flows are typically low viscosity flows.
true
What hazard? 1986 Lake Nyos, Cameroon, W. Aftica, kills 1700
volcanic gasses
What are the four hazards for volcanic eruptions?
volcanic gasses, lahars, pyroclastic flows, lava flows
Caldera
walled basin formed when magma chamber empties after largest eruption & supported roof of chamber collapses under its own weight (Crater, Lake Oregon)
Mud Pot
where hot acidic water start to break down rocks