core
an iron-rich sphere with a radius of 3,471 km
outer core: liquid iron-nickel-sulfur
inner core: solid iron-nickel alloy
order of earth's interior
-crust
-lithosphere (crust and upper most solid mantle)
-asthenosphere
-mantle
-outer core
-inner core
mantle
-solid rock layer between the crust and the core
- in convects: hot mantle rises, cold mantle
crust
-98.5% of the crust is comprised of just 8 elements!
- oxygen is by far the most abundant
movement in the mantle and in the crust...
-produces mountains(and volcanoes), causes earthquakes, creates the oceanic ridge system, tenches , and other features
- explains biological evolution patters
- supports Pangea theory
lithosphere
-the crust and the uppermost part of the mantle
- broken into giant plates that fit around the globe like puzzle pieces (called tectonic plates)'
-tectonic plates move slightly each year
asthenosphere
-ductile, plastic layer
-rocks actually flow--moving in response to the stresses from the churning motions of the deep interior of the crust
igneous rock
- formed below/on earths surface when magma wells up from the mantle and cools/hardens.
- main source of non fuel minerals (granite)
-forms bulk of earth's crust
sedimentary
-formed from sediment when preexisting rocks are weathered and eroded into small pieces and transported from their sources to a body of surface water (limestone, lignite, etc.)
metamorphic
-produced when preexisting rock is exposed to high temperatures/pressures, and/chemically active fluids (anthracite, slate, marble)
rock cycle
- be able to draw it
what are the two external processes
-weathering and erosion
erosion
-process by which material is dissolved, loosened, or worn away form one part of the earths surface and deposited in other places--culprits are streams/flowing water, wind, and human activities like deforestation
weathering
-produces loosened material that can be eroded
-mechanical:large rock mass broken into smaller fragments. frost wedging is a prime example
-chemical: 1 or more chemical reactions decompose a mass of rock
what powers the rock cycle?
-plate tectonic
what are the two must abundant elements in the earths crust?
-oxygen and silicon
which of the earth's layers of the earth is solid because of the extreme pressure its under?
? outer core?
what process drives the rock cycle?
extreme variance in mineral densities?
convection cells
-moves tectonic plates
-large volume of heated rocks rise from core toward upper mantle
-while this is happening, cooler rock sinks
-this creates slow, vertical currents
mantle plumes
- moves tectonic plates
- upwelling of abnormally hot rock (magma) within the earths mantle that rises to the surface, forming hot spots (volcanic centers)
what are the three ways plates interact
-divergent
-convergent
-transform
divergent plate boundaries
-plates pull apart
-new crust is created
-oceans are born and grow wider
- creates a land rift
-mid ocean ridges--new sea floors (underwater mountains with a valley in the middle)
convergent plate boundaries
-plates are pushed together, usually forming a trench
-crust is destroyed and recycled into the interior of the earth
- one plate dives under the other
- creates subduction zones--mountains and volcanoes are often found where plates converge
- creates tre
transfrom plate boundaries
-plates slide past one another along a fracture
what are the three convergent boundaries
-oceanic-oceanic
-oceanic-continental
-continental-continental
oceanic-continental convergence
-when an oceanic plate pushes into and subducts under a continental plate, the continental plate is lifted up and a mountain range is created
-deepest part of oceanic plate breaks up into small pieces which become locked into place for long periods of tim
oceanic-oceanic convergence
-two oceanic plates converge and one is subducted under the other
-deep oceanic trench is formed
- also results in underwater volcanoes
tsunamis
-result from underwater earthquakes
- one plate slides under the other, creating friction
- the friction slows down the ability of the subducted plate to slide--causes upper plate to become to distorted
-eventually, upper plate snaps back into its normal
continental-continental convergence
- two continents meet head on
-neither subducts bc. continental rocks are relatively light and resist downward motion
-instead, crust buckles and is pushed upward or sideways
transform-fault boundries
- when two plates are sliding horizontally past one another
- in between earthquakes, tectonic plates lock up at transform boundaries, causing pressure to build up over time
- during earthquakes, large amount of energy is released as plates suddenly/rapid
hot spots
-develop above mantle plumes
-melted rock (magma) rises through cracks and erupts to form volcanoes
-as the tectonic plate moves over the stationary hot spot, the volcanoes are rafted away and new ones form in their place. this results in a chain of volca
earthquakes
-occur on fault lines
- can cause the primary effect of soil liquefaction
- can cause the secondary effects of rock slides, urban fires, flooding, tsunamis
volcanoes
-occur when magma reaches earths surface through a long crack
- can release gases such as sulfur dioxide (acid rain) and water vapor/CO2 (global warming)
soil horizons
-caused by constant plate tectonic movement
-distinct zones
-each with unique texture and composition
o horizon
-surface litter
- fresh/decaying organic material (leaves, twigs, mosses,etc accumulated on the ground
a horizon
-topsoil
- top layer of soil which holds most of the organic matter and most of the water and nutrients needed for life
e horizon
-zone through which leaching occurs
-leaching is the process by which infiltrated water picks up nutrients and carries them down to deeper soil
b horizon
-subsoil
-zone that often contains an accumulation of minerals as well as some organic materials
c horizon
-zone composed of broken down parent material
- parent material is the basic type of rock from which the rest of soil is derived
bedrock
-parent material below the c horizon
clay
-very fine particles
silt
-fine particles
sand
-medium-sized particles
gravel
-course particles
loams
-soil with equal parts clay, sand, silt, and hummus
water infiltration
- the movement of water from the soil surface down into deeper layers
permeability
- the movement of air and water through soil
-important because it affects the supply of root-zone air, moisture, nutrients available for plant uptake
water-holding capacity
-soil with smaller particles have the ability to hold more water than soils with coarser particles
pH
-influences the uptake of soil nutrients by plants
clay's characteristics
- high nutrient holding capacity
- low water infiltration capacity
- high water holding capacity
- low aeration
-low workability
silt characteristics
-medium nutrient holding capacity
-medium water infiltration capacity
-medium water holding capacity
-medium aeration
-medium workability
sand characteristics
-low nutrient holding capacity
-high water infiltration capacity
-low water holding capacity
-high aeration
-high workability
loam characteristics
-medium nutrient holding capacity
-medium water infiltration capacity
-medium water holding capacity
-medium aeration
-medium workability
permeability
-the rate at which water flows through a substance (opposite of water holding capacity)
porosity
- the amount of space between particles that can be occupied by air or water
sand permeability/porosity
- rapid permeability
- porosity: low percentage of large pores
silt permeability/porosity
- low to moderate permeability
- intermediate porosity
clay permeability/porosity
- slow permeability
- high percentage of micro pores
describe the steps that should be taken to restore the land after the overburden has been replaced (mining)
1. recontour and regrade the land
2. add topsoil/nutrients to improve quality & structure
3. early successional species must be replanted
4. area must be monitored for 5-10 years to ensure regrowth takes place
5. replace vegetation
explain why the restoration of land would likely be more difficult in arid climate
-low precipitation
-low fertility of soils
- low water holding capacities or arid soils
- makes it difficult to reestablish vegetation
-as a consequence of slow growth of vegetation, reclamation may be prolonged because of wind and water related soil eros
describe one environmental impact that the sulfur content of the remaining coal and the tailings would have on the reclamation process and suggest a possible remedy
-they both contain sulfur, which can dissolve in water to form sulfuric acid, resulting in acidulation of surrounding soil, ground water, and adjacent bodies of water
this has devastating effects on plant growth and animal distribution
1 possible remedy:
other than mining and reclamation, describe two environmental impacts of using coal for energy
-burned coal releases sulfuric acid into the air causing acid rain
-coal emits a lot of CO2 which causes climate change
explain why per capita coal consumption in the United States is likely to increase
-lower overall cost compared to other energy sources
-higher availability in the US than other fossil fuels
-sustainability as an alternative source of energy necessitated by the reduction in the supply of other energy sources, such as oil
in what habitat would organic nutrients pass through rapidly
- a sandy desert
what is the correlation between the speed in which nutrients pass through the soil layers and the amount of rainfall each habitat receives
if it receives a lot of rainfall then nutrients will not pass through as quickly??
what habitat has the greatest potential for groundwater contamination and why
temperate rainforest because it will trap the water
why do desert habitats have larger c horizon than other habitats? Why are A and B horizons similar? how does this relate to the yearly rainfall that deserts receive?
- sand gets less rainfall and bedrock doesn't get broken down
- A&B are similar bc. they trap water???
????
describe relationship between texture and consistence
??
how might the consistence of soil affect the growth of plants? Think about both wet and dry conditions
sand can't be compacted, clay could (less space for water or air to get through--water logging
sand will allow water to fly through
law of superposition
-older rocks will be found under younger rocks
-this is a form of geologic dating
weathering
-the process of breaking rocks into sediments
- caused by extreme weather
in the creation of igneous rocks, what geological environment would allow magma to cool slowly? What environment would cause magma to quench (cool rapidly?)
- cool slowly on earths interior
-rapidly on surface
???
what was the difference between what you did to the sedimentary rocks and what you did to the metamorphic rock? (rock lab)
-sedimentary-- cut with rock
metamorphic--push with hands
what was the difference between what you did to the metamorphic rock and the igneous rocks? (rock lab)
-metamorphic--crush with hands
- igneous--put in ice/room temperature air
the rock cycle is a cycling of material to create various forms of matter. Does the rock cycle have to occur in the order that was done in class? (rock lab)
- not really--other than some steps, it can move in a couple different patterns
geologically, what would need to occur in order for the metamorphic sample to be turned into sediments? (rock lab)
-extreme weather like rain or snow
given that the rate of many geologic movements are in cm per year, how long do you think it might take for metamorphic rock to become sediments?
-Pangea shift took millions of years--this might be a matter of moths or days
at which boundary is a sea floor created?
-divergent
at which boundary is sea floor destroyed
-convergent
what are the three sub-types of convergent plate boundaries
-oceanic-oceanic
-oceanic-continental
-continental-continental
what geologic formations are found at convergent boundaries
-trenches
-mountains
-volcanoes
-islands?
what geologic formations are found at divergent boundaries
-new ocean floor
-rift valley
-trench
-mid-ocean ridges
what geologic formations are found at transform boundaries?
-earthquakes
-tsunamis
-san andreas fault
how is a new sea-floor formed at a mid-ocean ridge?
it is found over the rising plume of a mantle convection cell
this convection cell causes the two plates to move away from each other
as they move, the melted rock hardens and becomes new ocean floor
this process is how new earth surface is created!
rift valleys
-divergent boundaries can also be found on continents as rift valleys
- when a rift valley forms on land, it may eventually split the landmass wide enough so that the sea flows into the valley
-when this happens, the rift valley becomes a mid-ocean ridge
convection cells drive lithospheric plates
- convection cells in earth's lower mantle drive the lithospheric plates on the surface
- the rocks of the lower mantle are not brittle likes the rocks of the lithosphere
-they are hot enough so that they flow very slowly
-the core heats the rock material
subduction drives lithospheric plates
-the far edge of a lithospheric plate is much older than the edge close to the mid-ocean ridge that formed it
-over time, the far edge cools and becomes denser
-eventually, it may sink below another lithospheric plate and enter the lower mantle
-this sink
hot spots and island chains drive lithospheric plates
-mid-ocean ridges form when rising hot mantle rocks separate the plate above it
- sometimes a single hot rising plume, called a mantle plume, causes a volcanic eruption in the plate above it
-if the eruption is strong and lasts long enough, the volcanic e
mining effects on soil
-most soil is removed from site
-may be replaced only if reclamation occurs
reclamation
-restoring mine property to its usual state
young ocean rock is created by...
-divergent boundaries
rift valleys and mid ocean ridges are cause by..
-divergent boundaries
formed by weathering and erosion and then compaction
-sedimentary rock
formed when is existing rock is exposed to high heat and pressure
-metamorphic rock
what does soil compaction alter
permeability and porosity
tectonic plates, all of the crust, part of the mantle
lithosphere
top soil, rich in organic materials
a layer
ring of fire
75% of active and dormant volcanoes
thinnest layer of the earth
-crust
thickest layer of the earth
-mantle
san Andreas is a famous type of this boundary
-transform
how an igneous rock becomes an igneous rock
melting and then cooling
this layer of soil is considered the "subsoil" it has minerals in it that have been leached from higher layers
- b level
amount of space between soil particles
-porosity
this type of biome has a very large c level due to very little weathering
-desert
overtilling of soil allows topsoil to ...
erode
dirt poor summary
- with each generation, carrots become less good to eat. this is because agricultural practices that improve size , growth rate, and pest resistance, but hurt its nutrition. These "improvements" have hurt the vegetables uptake of nutrients. There have bee
pasture soil
- strutted is well developed with many pores and high amount of organic material
tilled soil
- hard, high density, low porosity, low infiltration, low organic material
to improve soil health, you have to increase organic matter and stimulate biological activity
root growth
-compacted soils do not allow roots to expand
-cracks and fissures are usually available for roots to grow through
-limits functions like crop anchoring, water and nutrient uptake
-roots concentrate in areas above/beside compacted zones
human spurred soil degradation and erosion
topsoil disturbance from plowing
devastating for plant growth, takes centuries to replace
soil compaction by machinery--alters porosity and permeability
nutrients depletion from overuse--pesticide pollution
porosity (human impact)
- as soil becomes more dense and compacted, it becomes less porous, making it harder for plants to grow. soil that has been plowed is more likely even more compact
nutrient uptake (human impact)
- soil compaction affects nitrogen by poor internal drainage, nitrate loss by leaching loss of organic nitrogen, and diffusion of nitrate and ammonia as well as phosphorous uptake bc of reduced root growth. therefore nutrient uptake is affected
penetration resistance (human impact)
root growth decreases linerally with penetration resistance
better indication of effects of soil compaction on root growth than bulk density bc results ban be interpreted independent of soil texture
soil
eroded rock, mineral nutrients, decaying organic matter, water, air, billions of living organisms