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Geology 1301 Final Review
Terms in this set (137)
James Hutton's hypothesis stating that current geologic processes could be used to explain past geological events
A weak zone of the mantle consisting of solid, heat softened rock
The Earth's tectonic plates are composed of:
3 types of plate boundaries
Convergent, Divergent, Transform
What parts of the Earth comprise the Lithosphere?
crust and the upper most mantle
What are the three types of rocks?
Igneous, sedimentary, metamorphic
form from magma
form from deposition of sediment
form from changes due to high pressure and temperature
A swirling cloud of dust and gas (the solar nebular) formed. In the center, it was hot and had high pressures where the Sun formed. As the outer part of the cloud cooled, solid particles condensed forming planets, moons and other solid objects
Solar Nebula Theory
1. Correlation of fossils on continents that are now separated
2. correlation of rocks and structures on continents that are now separated.
3. Fit of the coast lines of continents across the Atlantic Ocean.
4. Climate evidence
Alfred Wegener's hypothesis of Continental Drift
(the hypothesis was not accepted because he did not have a mechanism to explain it)
Most tectonic plates move _______ cm/year
Plate movement over stationary_______ indicated direction of movement for plate tectonics
--><-- move towards each other
subduction zones and continental collision zones
Convergent Plate Boundaries
<-- --> move away from each other
create oceanic ridges and continental rifts
Divergent Plate Bondaries
Plates slide past each other
Transform Plate Boundaries
Occur if one of both plates have oceanic crust
occur if both plates have continental crust
continental collision zone
About _______ years ago, most of the Earths's continents were joined together as the supercontinent Pangea
(crust and upper most mantle) broken into plates
is weak, and less dense (than the lithosphere) and deforms easily, promoting movement of plates
Mantle convection, slab pull, and ridge push
Downward movement of more dense material and upward movement of less dense material
A mechanism that contributes to plate motion in which cool, dense oceanic crust sinks into the mantle and "pulls" the trailing lithosphere along.
A mechanism that may contribute to plate motion. It involves the oceanic lithosphere sliding down the oceanic ridge under the pull of gravity.
Which of the following is not a characteristic of minerals
A substance formed by the chemical combinations of two or more elements in definite proportions and usually having properties different from those in its constituent elements.
A substance that cannot be decomposed into simpler substances by ordinary chemical or physical means.
The smallest particle that exists as an element.
Which group makes up 90% of the minerals in the crust?
Electrons are transferred from one atom to another
Atoms share electrons
Minerals are identified by:
their physical properties
What are the physical properties that identify minerals:
Cleavage, fracture, color, luster, hardness, etc.
One silicon atom with four oxygen atoms surrounding it:
Which two elements make-up a majority (80%) of the Earth's crust?
Silicon and Oxygen
Igneous rocks are identified based on:
Mineral composition and texture
What is the most important factor in determining igneous rock texture?
Cooling Rate : (slow=large crystals and fast=small crystals)
The types of igneous rock which characterize the continental crust are:
granite and rhyolite
The types of rock which characterize oceanic crust are:
The most common igneous rock formed at divergent plate boundaries is:
A tabular pluton that is nearly vertical is a :
A tubular pluton that solidifies between layers of horizontal rock is a:
An intrusive Igneous rock structure
Less silica, more iron and magnesium (mostly dark colors)
More silica, less iron and magnesium (mostly light colors)
Why are magmas which form in subduction zones more felsic than those forming oceanic crust at divergent plate boundaries?
Magma assimilates (melts and incorporates) some minerals in the overlying crust
Describe the effect of pressure on the melting temperature of dry and wet rock
Pressure INCREASES melting temperature of dry rock and DECREASES melting temperature of a wet rock
Where do most volcanoes occur?
Above subduction zones
________ is the primary component of all magmas
Basaltic eruptions are explosive because the magma is:
very hot with low silica (SiO2) content
Felsic eruptions are explosive because the magma:
has high viscosity and high pressure from volcanic gases
Magmas with low viscosity have:
low silica (SiO2) content and high temperatures
land slides, poisonous gases, fires, mudflows (lahars) and pyroclastic flows
Mafic magma, low viscosity- non-explosive eruptions, very large and wide cone because lava flows a long distance.
Felsic-intermediate, high viscosity, explosive eruptions, and narrow-steep cone.
Dissolution, Oxidation, Hydrolysis.
Thermal expansion and contraction, frost wedging, unloading, abrasion, crystal growth.
What is the most important factor that influences the rate of chemical weathering?
3 minerals that are stable at the Earth's surface
Quarts, Clay-minerals, and iron oxides
physically breaks down rocks into smaller pieces
changes the mineral composition of the rock
Physical or chemical alteration of a rock
transportation of weathered material
Weathering, erosion, deposition, lithification(compaction and cementation)
formation of Sedimentary Rocks
The process of changing unconsolidated sediment into sedimentary rock? (compaction and cementation)
grains that are all about the same size
Well sorted sediment
Most sediments at the earth's surface are:
Detrital and formed by mechanical weathering
Chemical sedimentary rocks are classified based on:
Detrital sedimentary rocks are classified based on:
Sedimentary structures are features which develop in sediment......
Features of sedimentary rocks that reveal the rock's depositional environment are:
Sedimentary structures, types of fossils, rock types, maturity
______ most common sedimentary environments on land.
Differential stress results in _______ texture.
What type of plate boundary is associated with differential stress?
Convergent Plate boundaries
Confining pressure results in a ________ texture.
the degree to which a metamorphic rock has been changed. (low grade=little change, high grade=high change)
the alignment of platy minerals in a metamorphic rock caused by differential stress
Metamorphism is the process by which heat, pressure and chemical reactions alter the mineral content and/or structure of preexisting rock WITHOUT melting.
What type of rocks can become metamorphic rock:
All types: igneous, sedimentary and metamorphic
the increase in temperature with depth below the earth's surface is the:
5 types of metamorphism
Contact- contact with magma
Burial- deep burial by sediment
Regional- at convergent plate boundaries
Hydrothermal- chemical reaction with hot water
Impact- meteorite impact
Factors that determine the type of metamorphic rock which may form:
Temperature, pressure, water, composition of parent rock
determining the chronological order in which geologic events occurred is:
Determining the actual age of a rock in years is:
The erosional surface between an underlying sedimentary rock that has been tilted, eroded and overlain by another sedimentary rock is a(n):
Which organism would make the best index fossil?
lived over a wide geographic range for a brief period of geologic time
The principle that most sediments are deposited as horizontal layers
the principle of Original horizontality
The principle that younger sediments are deposited on top of older ones is:
the principle of Superposition
Time required for 1/2 of a radioactive isotope to decay to the daughter isotope
after 1 half-life, ______ % of the parent isotope remains and _______% has decayed into the daughter isotope,
after 2 half-lives_____% parent, ______% daughter
after 3 half-lives_____% parent, ______% daughter
Which type of rock is most useful for radiometric dating?
The actual age of the earth based on the ages of meteorites and moon rocks is:
4.6 Billion years
Why can't we determine the age of the Earth from Earth rocks?
Earth rocks were destroyed by plate tectonics, weathering, etc.
_____ and _____ can be used to determine a 3-D subsurface picture of geologic structures
Strike and Dip
Arch shaped fold where oldest rocks are in the center, and beds dip away from the fold axis.
a trough shaped fold where the youngest rocks are in the center and the beds dip towards the fold axis.
Anticlines and Synclines result from ______ stress
Occurs at convergent boundaries
tensional stress at divergent plate boundaries; hanging wall moves down relative to the footwall.
compressional stress at convergent plate boundaries; hanging wall moves up relative to the footwall.
shear stress at transform fault plate boundaries; movement is mostly horizontal (San Andreas)
What is the effect of isostasy on land surface elevation?
Thicker, lower density crust has higher elevation
Compressional waves, fastest seismic waves (arrive at seismograph first), travel through SOLIDS, LIQUIDS and GASES.
Shear waves, Slower than P waves, travel ONLY through solids
instruments used to measure the intensity of earthquakes
Explain the role of the core in generating the Earth's magnetic field.
Convection/Circulation of the outer core causes a magnetic field.
A continental margin that does not have a plate boundary
A continental margin that has a plate boundary
Mid-ocean ridges indicate a _________ plate boundary
deep-ocean trenches and lines of volcanoes indicate a ________ plate boundary
The primary force driving mass wasting
Types of mass wasting are classified by their _____ and ______ of movement
speed and manner
circulation of water among oceans, land, atmosphere, etc.
Where is most of the water on Earth located?
Where is most of the freshwater on Earth located?
Glaciers and Ice caps
A _______ _________ separates one drainage basin from another.
soluble minerals dissolve in stream
fine particles remain suspended in the water all the time
saltation- medium particles bounce along the bottom.
traction- large particles roll along the bottom.
Recommended textbook explanations
Pearson Earth Science
Dennis G. Tasa, Edward J. Tarbuck, Frederick K. Lutgens
Edward J. Tarbuck
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