BYU GEO 101 Exam 2 – Flashcards

Unlock all answers in this set

Unlock answers
question
What is weathering?
answer
The breakdown of rock by physical and chemical reactions with air and water.
question
How do smooth rocks get cracks?
answer
-Naturally occuring from the expanding and contracting from the cooling process
-Earthquakes
-Lava - as it cools, it contracts, causing cracks
question
These affect the type and rate of weathering.
answer
Climate and rock type
question
Rock breaks down faster in this type of climate.
answer
Hot, moist climates
question
Joints in rocks
answer
Fractures. Results from tectonic stresses of contracting to to cooling igneous rock.
question
Three types of tectonic stress
answer
Compressive
Tensional
Shear
question
How is columnar basalt formed?
answer
When the lava cools, in contracts towards a center point, creating a 5 or 6 sided column.
question
What is physical weathering?
answer
The mechanical fragmentation of rocks from stress.
question
What are some types of physical weathering?
answer
-Frost wedging
-Thermal weathering
-Wetting drying (hydration)
-Unloading (exfoliation)
-Salt wedging
-Biological weathering
question
Frost wedging
answer
when water gets into a crack, and the freezes, expanding the crack
question
Thermal weathering
answer
The weather changes from hot to cold
question
Wetting drying (hydration)
answer
Absorption of moisture causes swelling.
question
Unloading (exfoliating)
answer
Expanding after heavy loads are removed, or the expanding removes some rock.
question
Salt Wedging
answer
Water settles into the cracks, evaopartes, but leaves the salt behind. Salt crystals grow and shatter the fence post.
question
Biological weathering
answer
Plant roots can expand cracks.
Burrowing animals carrying air and water down into bedrock.
question
What is chemical weathering?
answer
Chemical reactions with minerals that break down rock.
question
Three types of chemical weathering
answer
-Hydrolysis
-Oxidation
-Dissolution
question
What is hydrolysis?
answer
A chemical reaction between water and another substance to produce a new compound that is usually weaker than the original
question
What is oxidation?
answer
When oxygen dissolved in water comes into contact with certain rock minerals.
question
What is dissolution?
answer
The process by which a solid, liquid or gas forms a solution in a solvent
question
What is a karst?
answer
Chemical weathering where limestone bedrock dissolves when it comes in contact with groundwater.
question
What landforms produced from the karst process?
answer
-Sinkholes
-speleothem (the caves)
-haystack hills
-tufa cones
question
What is a speleotherm?
answer
A cave created thru the karst process. Contains stalactites and stalagmites.
question
How are haystack hills formed.
answer
Over time, sink holes from the karsting process merge together. the ground left behind are known as haystack hills.
question
Name some hydrothermal features.
answer
Geysers
Hot springs
Fumaroles
Tufa cones
question
What are geysers?
answer
Where groundwater comes in contact with heated igneous rock below the surface. As the water heats, the pressure builds until it blows.
question
What are hot springs?
answer
Where ground water comes in contact with heated igneous rock, but it is not under pressure.
question
What are fumaroles?
answer
Like a geyser, but instead of water, it is just steam.
question
What are tufa cones?
answer
The result of overflow of warm groundwater. Midway at the Homestead.
question
What is mass wasting?
answer
The down slope movement of earth material due to gravity.
question
How does water affect mass wasting?
answer
Water lubricates, makes everything slippery and adds weight. It saturates the soils.
question
Most important factors in slope failure
answer

Saturation of slope material with water

 Earthquakes

 Freezing and thawing

question
Types of slope failure
answer
Rockfall
Slump
Earth or mudflow
Solifluction
Creep
question
Describe rockfall
answer
Cracks in rocks indicate water erosion. Rockfall can be one rock, or lots. Accumulated rocks and the bottom of a cliff is called Talus.
question
Describe slump
answer
It creates step-like terraces as it slumps down.
question
Describe earth or mud flow.
answer
Lots of water, like a muddy river. Very moist environment
question
Describe solifluction.
answer
Occurs in extremely cold environment, high altitude, in permafrost. The top few inches or feet thaws and starts to slide over the frozen layer. Creates irregular terrain.
question
What is Pangaea?
answer
The supercontinent that was made up of all landmasses on the earth
question
What is Laurasia?
answer
The north portion of the supercontinent Pangaea.
question
What is Gondwana?
answer
The southern portion of the supercontinent Pangaea.
question
Describe Continental Drift.
answer
Alfred Wegner's theory that the continents were drifting across the ocean bed. He recognized the puzzle-like shape of the continents and the plant, wildlife and rock that matched on continents separated by ocean. Unfortunately, he did nt know the mechanism behind the theory and so it was dismissed.
question
Describe Plate Tectonics.
answer
The lithosphere is made up of large plates that shift and move as a result of convection. Plates were dicovered through seafloor mapping and mapping of earthquake patterns.
question
Seafloor spreading
answer
Discovered thru Paleomagnetism and Ocean Rock Floor Sampling
question
What is a Hot Spot?
answer
A spot deep in the mantle which leaks hot magma/lava to the the earth's surface. Hot spots do not move. The Hawaiian islands were created by hot spots. Yellowstone has one.
question
What is an accreted terrane?
answer
The addition of material to a plate during the subduction process. Accounts for geologic incongruities between continental interiors. NV, OR, WA all accreted onto the North American Plate.
question
What is Diastrophism?
answer
Deformation of the earth's crust, particularly thru folding and faulting
question
Describe earths folding.
answer
It is the result of compressional forces. Downfold is a syncline, upfold is anticline, monocline does not fold.
question
Anticlinal Valley
answer
Where the layers of bedrock erode quickly because of folding and looks like a syncline, but is not.
question
Describe faulting.
answer
Rock that has been forcefully broken. Occurs along zones of weakness in the earth's crust. Common in Coastal areas
question
Shield volcano
answer
Broad domes. Wider than it is tall.
Magma is extremly hot and very runny. Gas bubbles rise to the top and are released into the atmosphere. Found over hot spots. Hawaii.
question
Composite or strato volcano
answer
Magma is cooler, thick, pasty and viscous. Bubbles cannot rise so the pressure builds until there is a large explosion. Cone shaped. Mt Pinatubo
question
Name some extrusive volcanic landforms.
answer
Shield or composite volcanoes, and caldera.
question
Name some intrusive volcanis landforms.
answer
Batholith
Laccolith
Dike
question
What is a batholith?
answer
Magma that cools and solidifies below earths surface. Igneous Intrusive. Usually Granite.
question
What is a laccolith?
answer
Magma that gathered in one spot between two sheets of sediment. Pushes the upper layer upward.
question
What is a dike?
answer
A vertical layer of magma that melted its way up.
question
Wegner's evidences for continental drift.
answer

-Puzzle-like fit of widely separated continents

-Similarity of rock and mountain formations near coastlines of separated continents

-Matching fossils of extinct species on widely separated landmasses

question
Three types of plate boundaries.
answer
Divergent
Convergent
Transform
question
Describe a divergent plate boundary.
answer

Where the boundaries are being pushed apart. This happens at ocean ridges, were the convection process pushes magma up and pushes the boundaries apart.

Mid-Atlantic Ridge

question
Describe a convergent plate boundary.
answer

Where plates come together. Oceanic plates collide, denser one gets drawn down. Friction causes magma to move up. Unsubducted plate will have island chain. Aleutian Islands. 

Oceanic-Continental - Oceanic is more dense, so it will subduct and create a volcanically active mountain range. Cascade Mtn Range.

Continental-Continental - They don't subduct, so they move up, creating mountains. Himalayan Mountains.

question
Describe a transform plate boundary.
answer
The plate are sliding past eachother. San Andreas Fault.
question
Example of landforms assciated with faulting.
answer

Block Mountain Range - the Wasatch Range.

Horsts and Graben - Great Rift Valley in Africa

question
Stream Discharge
answer
The volume rate of water flow. Amazon has greatest discharge.
question
Tributary
answer
A small stream that jons another. Small streams have no tributary.
First stream orders are without tributaris. When two first-order dtreams combine, they are called a 2nd order stream.Eighty percent of streams are 1st, 2nd, or 3rd order.
question
Channel
answer
The trough water travels in.
question
Fluvial transportation
answer
All streams transport sediment. Stream-transported sediments are eventually deposited in a river or ocean.
question
Types of fluvial transportation
answer
Dissolved load - salt/minerals
Suspended load - clay and silt
Bedload - sand and larger
question
Characteristics of bedload
answer
Carries partciles the size of sand or larger.
Saltation is the bouncing of sand as it goes down the stream
Traction is the process of pushing larger rocks down the stream
If a stream doubles in speed it can carry rocks 64x heavier.
question
Name four channel patterns.
answer
Straight
Meandering
Sinuous
Braided
question
Describe how a delta is formed.
answer
As streams dump into the cean, they deposit sediment in theo the sea until the sediment builds up and blocks the stream, rerouting the water. Mississippi River.
question
Describe a floodplain
answer
Flat or nearly flat plain adjacent a river. Extends to edges of valley, created by meandering. Floods when river is full.
question
What is a levee?
answer
A natural or artificial earthen ridge that runs parallel to a river to prevent overflow.
question
Effect of stream gradient.
answer
Higher gradient (steeper) river flow faster, can carry more stuff.
question
What is a Yazoo stream?
answer
A small tributary that runs paralle to a larger stream. Will Usually join the larger one. When levees form, it has a harder time eroding through.
question
What is a distributary?
answer
A stream that branches off from the main channel. Usually occurs near an cean or lake.
question
What is an oxbow lake?
answer
A cutoff meander. The water ct through the rock, leaving a u-shaped river.
question
What is alluvium?
answer
Sediment deposited by a stream.
question
What is a canyon?
answer
A ravine between cliffs carved by water.
question
What is a bluff?
answer
A cliff near a river which has not been eroded yet.
Erosional landform
question
Where will you find a sand bar or point bar? How is it created?
answer
On the inside of a meandering stream.The water inside the curve is mving slower, so it deposits some of its sedimentry content.
question
The difference between perennial and ephemeral streams.
answer
Ephemeral streams are occaisional, they don't flow all year. Perennial streams run al year.
question
Erosional and depositional dynamics of river meanders.
answer
As meanders curve, they erode the outer edges and deposit on the inner edges.
question
What are paired terraces?
answer
Terrace at opposite sides of a river that match in height. Reflects where the river bed was before it cut down into the earth. Erosional.
question
What is an entrenched meander?
answer
The same as incised. It cuts down into the earth.
question
Describe a knickpoint retreat.
answer
The river bed is resistant to erosion, be the earth underneath that layer is not. At water falls, the water erodes the less resistant layer, causing the bed layer to fall because it has no support. Niagara Fals used to retreat 3 feet per year. Now it is closer three inches every decade. They rerouted the water for energy.
question
Subduction zone island chains
answer
Oceanic subducting: Aleutian Islands
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New