GEOL 201 Quiz 1
metamorphic rocks that form at relatively low temperatures in a shallow subduction zone
low-grade rocks
As more of the rock melts during partial melting, the magma becomes more ________ than the original melt that formed.
mafic
limestone metamorphoses into
marble
Refractory materials
melt only at high temperatures
A naturally occurring, crystalline solid, with a constant chemical composition and a characteristically ordered internal structure
mineral
Within the solar core: Gravity creates intense ___________.
pressure
spontaneous transition from a less stable isotope to a more stable one
radioactivity
ratio of parent to daughter indicates element's _____________ ______
radiometric age
slate metamorphoses into
schist
At a divergent boundary, two oceanic plates move apart by the process of ___________ ____________
seafloor spreading
basalt, peridotite metamorphoses into
serpentinite
shale metamorphoses into
slate
What is the stream of charged particles given off from the Sun called?
solar wind
the mantle is composed entirely of _________ _________________
solid peridotite
the primary difference between lithospheric and asthenospheric mantle that gives rise to numerous different patterns of physical behavior is __________________
temperature: the lithosphere is cooler than the asthenosphere
it is believed that our solar system resulted from a second- or third-generation nebula. How do we know this?
the mix of complex elements suggests this
if one geologic feature cuts across another, the feature that has been cut is older
the principle of cross-cutting
sediments generally accumulate in a continuous sheets within a given region
the principle of lateral continuity
layers of sediment, when first deposited, are fairly horizontal
the principle of original horizontality
in a sequence of sedimentary rock layers, each layer must be younger than the one below, for a layer for sediment cannot accumulate unless there is already a substrate on which it can colect
the principle of superposition
physical processes we observe operating today also operated in the past
the principle of uniformitarianism
a network of pathways by which rocks can be altered and reformed into different rock types
the rock cycle
One plate slides sideways past another, without the production of a new plate or the subduction of an old one. The boundary is marked by a large fault, a fracture on which sliding occurs. Transform boundaries link segments of mid-ocean ridges They may also cut through continental lithosphere.
transform boundaries
A boundary at which two plates slide past each other
transform boundary
Formula for heat
H + H yields He + heat
Star: Accumulation of matter mostly of what elements?
Hydrogen and Helium
Deep areas that reach depths greater than 5 km
Trenches
Differentiate the characteristics of volatile materials and refractory materials. A. hydrogen and helium are examples B. freezing yields rocky/metallic solids C. melt/vaporize at lower temperatures D. freezing yields ices
Volatile: A, C, D Refractory: B
Trenches border _______ _______, curving chains of active volcanoes
Volcanic arcs
a rock containing an inclusion must be younger than the inclusion
a principle of inclusion
Geologic Time Scale
cenozoic 66 Ma mesozoic 252 Ma paleozoic 541 Ma precamrbian 4.543 Ga
Order the steps in continental rift formation.
1. The lithosphereic mantle begins to stretch horizontally and thin vertically. 2. The crust fractures, and faults develop. 3. Large fault blocks of crust slide down into the widening rift. 4. Magma erupts as lava, creating volcanoes along and near the center of the rift.
what are the 5 elements of soil formation
1. bedrock 2. topography 3. climate 4. organisms 5. time inexorable
agents of metamorphism
1. change in temp./pressure 2. application of stress 3. exposure to hydrothermal fluids
Opholite sequence of MOR
1. oceanic sediment 2. pillow basalt 3. sheeted dikes 4. massive basalt 5. grade to gabbro 6. Moho 7. mantle (peridotite)
The Basic Principals of Plate Tectonics
1. plates move relative to each other 2. as it moves its internal area remains mostly rigid and intact
sources of radioactivity
1. primordial, long-lived 2. decay products of primordial elements 3. cosmogenic 4. human produced
Steps of sedimentary rock formation.
1. weathering 2. erosion 3. transportation 4. deposition 5. lithification
Continental Crust (___ Distilled) These 'lightest' materials are concentrated in continental crust relative to oceanic crust
2
current atmosphere is comprised of?
78% N2 21% O2
Two plates move together, and one plate subducts beneath another (it sinks down into the mantle). Only oceanic lithosphere can subduct. At Earth's surface the boundary between the two plates is marked by a deep ocean trench. During subduction, melting above the downgoing plate produces magma that rises to form a volcanic arc.
convergent boundaries
A boundary at which two plates move toward each other so that one plants sinks beneath the other
convergent boundary
Two plates move apart by a process called seafloor spreading. A MOR delineates a divergent boundary. Asthenosphereic mantle rises beneath a mid-ocean ridge and melts, forming magma. The magma rises and solidifies to become new oceanic crust. The lithospheric mantle thickens progressively away from the ridge axis as the plate cools.
divergent boundaries
A boundary at which two plates move apart from each other
divergent boundary
Atoms that are heavier than iron are generally produced by?
explosions of supernova
Partial melting results in magmas that are more ________ in composition than the parent rock.
felsic
_________ components of the parent rock tend to go into the liquid state first during partial melting.
felsic
The Sun was created at the center of the accretionary disk when the temperature became high enough for __________ to occur
fusion
granite metamorphoses into
gneiss
Matter creates __________.
gravity
measure of how quickly an element decays, same amount of time to reduce the present number of atoms by half
half-life
metamorphic rocks that form at relatively high temperatures
high-grade rocks
Volatile materials
hydrogen, helium, methane, ammonia, water, and carbon dioxide, melt at low temperatures
with increasing distance from a MOR, the age of oceanic crust _____________
increases
metamorphic rocks that form at relatively intermediate temperatures
intermediate-grade rocks
Which of the following statements about differentiation are true? A. The mantle formed as a result of differentiation. B. The Moon formed as a result of differentiation. C. The Earth is round because of differentiation. D. The core formed as a result of differentiation.
A, D
Mantle Material (____ Distilled) result of planetary differentiation
0
Oceanic Crust (___ Distilled') these 'lighter' materials are concentrated in oceanic crust relative to the mantle
1
Order the events chronologically that occurred in the formation of our Solar System.
1. An accretionary disk formed. 2. A protosun formed. 3. Rings formed in the protoplanetary disk. 4. Planetesimals collected to from protoplanets.
Sources of heat that prolong the cooling of Earth
1. Latent heat release 2. Primordial heat from bombardment 3. Heat from radioactive decay 4. Friction from solid Earth tide
Place in chronological order the events that led to the formation of the Earth.
1. The Earth cleared its orbit of all other matter, making it a true planet. 2. The Moon formed. 3. Volcanic activity occurred, releasing gases. 4. An atmosphere formed.
Identify statements true of earthquakes. A. Most earthquakes occur along plate boundaries. B. Most earthquakes are the consequence of plate tectonics. C. Most earthquakes are large and destructive. D. An estimated one million earthquakes occur each year, but most of them are small.
A. Most earthquakes occur along plate boundaries. B. Most earthquakes are the consequence of plate tectonics. D. An estimated one million earthquakes occur each year, but most of them are small.
Cite natural phenomena that can cause tsunami formation. A. landslides B. earthquakes C. volcanic eruptions D. hurricanes
A. landslides B. earthquakes C. volcanic eruptions
The geothermal gradient A. refers to the rate of change in temperature with depth in the Earth. B. averages about 5°C per km in the upper crust. C. increases as you go deeper into the Earth. D. states that temperatures near the mantle-core boundary may exceed the temperature of the Sun (5,500°C).
A. refers to the rate of change in temperature with depth in the Earth.
Accretionary prisms form due to what process? A. subduction B. divergence C. rifting D. transform motion
A. subduction
Identify the statement(s) that are true of nebulae: A. Most of a nebula is hydrogen and helium left over from the Big Bang B. A single large nebula can be a nursery for a large number of stars. C. Solar systems form within a nebula. D. Nebulas are vast swirling clouds of gas and dust floating in space.
All.
Where growth is inhibited, no faces result
Anhedral Crystals
Warmer mantle that can flow very slowly when acted on by a force
Asthenosphere
What information can meteorites provide about Earth? A. changes in Earth's orbit B. the average composition of the whole Earth C. Earth's age D. the composition of Earth's core E. the composition of Earth's crust
B, C, D
Cite factors that can result in metamorphism. A. weathering and erosion B. increased pressure C. hydrothermal fluids D. increased temperature
B., C., D.
Why is the outer core the only layer in Earth that is molten? A. the pressure decreases within Earth, thus allowing iron to melt B. the pressure increases within Earth, thus allowing iron to melt C. the temperature is high enough but pressure low enough to melt iron D. the temperature is high enough but pressure low enough to melt olivine
C.
Identify the FALSE statement about stellar nucleosynthesis. A. In stellar nucleosynthesis, reactions are caused by fusion. B. Stellar nucleosynthesis is the term for the process by which stars create intermediate weight elements. C. Stellar nucleosynthesis produces heavy elements with atomic number greater than iron. D. Stellar nucleosynthesis is a normal process that happens during the life cycle of stars.
C. Stellar nucleosynthesis produces heavy elements with atomic number greater than iron.
Atoms that are heavier than iron are generally produced by? A. fission reactions within a star. B. normal fusion reactions during the lifetime of the star. C. high-energy fusion reactions during the explosion of supernovae. D. the Big Bang.
C. high-energy fusion reactions during the explosion of supernovae.
carbonate equilibrium formula
CO2 + H20 + Ca2 <----> CaCO3 + 2H+
photosynthesis formula
CO2 + H20 ----> CH20 + 02
Sort outcomes of continental collision versus those related to ocean-ocean (oceanic) convergence. A. crustal thickening B. subduction C. volcanism D. mountain building
Continental: A. crustal thickening D. mountain building Oceanic: B. subduction C. volcanism
The Lithosphere consists of?
Crust and upper mantle
The boundary separating the crust from the mantle is called the A. lithosphere. B. heliosphere. C. asthenosphere. D. Moho.
D. Moho
Narrow bands of vertical cracks and broken-up rock cut the ocean floor of mid-ocean ridges
Fracture zones
The velocities of seismic waves traveling from earthquake foci: A. monotonically increase with depth, at a consistent rate of acceleration. B. are uniform throughout all layers of Earth. C. monotonically decrease with depth, at a consistent rate of deceleration. D. generally increase with depth, occasionally making abrupt jumps termed seismic-velocity discontinuities.
D. generally increase with depth, occasionally making abrupt jumps termed seismic-velocity discontinues.
Earth's core A. is divided into two parts-the lithosphere and the asthenosphere. B. is under such intense pressure that it is made of solid iron. C. the thinnest layer of Earth's interior. D. generates Earth's magnetic field.
D. generates Earth's magnetic field.
How can plate tectonics explain the systematic patterns we observe?
Earthquake distribution, age of seafloor crust, continent, ocean distribution
Where crystals can grow into open space, good crystal faces result
Euhedral Crystals
Describe the process of seafloor spreading.
Magma rose upward at MOR and solidified to form the basalt of oceanic crust. New seafloor moved away from the ridge axis, leading to the widening of the ocean basin.
Where does the first distillation of the mantle occur?
Mid ocean ridge forms oceanic crust
Submarine mountain ranges whose peaks lie only about 2 to 2.5 km below sea level
Mid-ocean ridges
Describe the process of fractional melting (distillation)
Mix of minerals in earth's crust surrounded by molten material, some minerals melt due to lower melting points while others remain solid. Solid minerals will sink into molten material, which rises to the surface creating the crust.
Boundary between crust and mantle
Moho
soil horizon development
O-organic horizon A-organic rich mineral horizon E-zone of eluviation (leaching) B-horizon of accumulation (clay mineral horizon) C-partially altered protolith BEDROCK
Compressional wave is a seismic body wave that shakes the ground back and forth in the same direction and the opposite direction as the direction the wave is moving. Can travel through both solid and liquid parts of the Earth. Travels faster
P-waves
____________ in the core forces atoms together into very close proximity.
Pressure
Shear wave, is a seismic body wave that shakes the ground back and forth perpendicular to the direction the wave is moving. Can travel only through solids. Travel slower.
S-waves
Describe the formation of MOR
Seafloor spreading takes place, hot asthenosphere rises and magma forms. Fractional melting occurs in magma. Some material cools, while the rest of the liquid magma rises to fill the cracks, creating dikes. Some magma makes it to the surface of the seafloor and spills out lava, which cools to form pillow basalt.
Isolated submarine mountains, which were once volcanoes but no longer erupt
Seamounts
Stellar Nucleosynthesis: Elements through Iron (Fe) created in?
Stars (fusion)
Elements beyond Iron (Fe) created in?
Supernovae (fusion)
What are the source material of nebula?
Supernovae and stars
which type of magma has the highest amount of the mineral olivine?
ultramafic
when were BIFs present in earth?
~2.6 to 1.9 Ga
when did earth's magnetic field form?
~3.99 Ga