Test One Flashcards
“Snows of kilmenjaro” by Hemingway
85% of our glaciers have melted and there hasn’t been such a high rate of melting since the 1900s but we have had droughts
Spheres of earth
- Geosphere-earths interior
- Pedosphere-soil
- Hydrosphere-water
- Biosphere-living things
- Atmosphere-air
- Cyrosphere-water in solid form
Chemical differentiation as earth cools
- Core:physical=solid iron
- Mantle:liquid
- Crust:earths surface
Stock v reservoir
Stock: your resource, what you’re taking
Reservoir:stock holder, what you’re saving
Types of systems (between stock and reservoir?)
Open: anything (matter and energy) in and out (ie ocean/lake rain goes in then water evaporates out)
Closed: things go in but can’t get back out (
Ike sun in a glass fishbowl)
Isolated: no change, not in or out
Dynamic: changes: more in or more out
Static: stays the same: some in some out
Steady state
When the stocks in a dynamic system remains balanced w time even though matter is being exchanged
Lithosphere
Crust broken into plates floating on upper mantle
Astherosphere
Upper mantle
Types of rocks
- Igneous
- Metamorphic
- Sedimentary
Two types of behaviors
Linear: even predictable
Exponential: spikes indefinitely like population
Reinforcing and balancing
Reinforcing: process may arise promoting further change in same direction; positive feedback
Ie) Ice, reflects sun so it’s colder so more ice forms
Balancing: change in one direction leads to events that reverse direction; negative feedback
Ie) clouds coverage
Pedosphere
Weather, erosion, decomposed rock.
Critical zone regulates natural things to provide life
Geosphere
Earths metallic interior and rocky outter shell
Hydrosphere
All water
- most is salt water or freshwater that is locked up
- hydrologic system (water cycle)
Atmosphere
Envelope of gases
21% oxygen
-everything else small amount
-co2 (and methane?) small naturally occurring but it’s increasing
We live in “troposphere” where oxygen is at its most comfortable level
Biosphere
Us :)
8.9 mil species
Lots depend on photosynthesis
60-90% of all cells is water: this is an example of the interaction between the biosphere and hydrosphere
-another example is the fact that carbon is the building blocks of cells
Cyrosphere
Ice
Frozen
Amount depends on the climate
States of energy
Gas, liquid, solid
-exchanges throughout the spheres
Types of energies (measured in calories?)
Kinetic-moving
Potential-held back energy like water at a dam
Thermal-heat energy
Energy starts by….
Coming from the sun
Insulation: how much sun/energy enters the earth
-some energy is trapped y clouds and greenhouse gasses
Energy budget
25% reflected by clouds
5%reflected by earths surface
25% absorbed by clouds
45% reaches us
Most energy we absorb
Fossil fuels (81%) Geothermal Per country or per person (per capita)
Human population
Number one problem in environmental geology
Total Impact=individual impact x number of people
Hunters and gatherers
40k-9k bc
Less than a few mil people
Preindustrial period
9 bc
6 million people
Population growth
10% more people each year?.
10.1% growth of population per year?
Human population over time
100 years ago : 1-2 bil
40 years ago: 2.4 bil
30 years ago: 4-6 bil
2011(7 years ago): 7 bil
Limited resources
Renewable: we use but quickly replaced (sustainable)
Non renewable: finite/exhaustible
Inexhaustible: cant be depleted by human activity
-prolly soil but there was the dust bowl
-wind
Yeild
Most we can do without depleting a resource and giving it time to grow back
Sustainability
To ensure resources are available for the future Why: -socially just -economy -environment
Pollution
Contamination of a resource one with undesirable material
Waste
What’s left over after using a resource
Environmental impact
Population and per capita, amount environment segregation per resource
How do we know if pollution is causing degradation
If pollution per unit resource is high
- over population
- over consumption
Geological hazard v natural disaster
Geological hazard: Natural phenomenon/process, event with negative affects on human, environment, or property
Natural disaster: Sudden change results of ongoing process that affects humans, environment, or property
Risk
Magnitude of potential death, injury, or loss of property due to a particular hazard
Anthropocene
Time people have been here
Planetary boundaries
Operating in safe way for humanity
-absolute values uncertain
Energy
Ability to do work or a change brought about when force is applied
-kind of a system within itself like the sun
Processes
The manner in which change to a system occurs
- erosion
- subduction
Resource
Anything we get from our planet
Over consumption versus over population
Over consumption: one person using more than they need
Over population: too many people for the resources available (sometimes due to over consumption)
Parts of Scientific method
- Hypothesis- explanation of observations that’s based on physical principles
- Theory- hypothesis that’s survived repeated testing and accurately explain a wide variety of phenomenon
- Universal unifying theory- a theory that explains many types of phenomenons and has survived all challenges
Pseudoscience
False sciences, presented to be true but not
Difference between ocean crust and continental crust
Ocean crust: thin
Continental crust: thick
Isostacy
Mountains have deep roots so rise higher
Normal faults vs reverse faults
Normal: Where lithosphere (foot wall) rock slides downward relative to other rocks (hanging wall) along fractures
Reverse: hanging wall moves up relative to foot wall
Types of plate boundaries
- Divergent- two plates move away from each other. Constructive, builds land
- Convergent: where two plates collide. Two intersections can occur: A) continental-ocean or ocean results in subduction (one sliding under the other)
B) continental continental results in mountain building by pushing against each other and raising - Transform-two plates slide by each other
Cons of reverse fault
- can produce earthquakes with megathrust
- faulting is brittle deformation
- inained Plane of failure separates rocks on either side of the fault
Thrust fault
Occurs when the plane of failure separating rocks on either side of the fault is less than 30 degrees from horizontal
Ductile deformation
Convergent boundaries are also locations of ductile deformation
-ingest temp and pressure cause rocks to behave like liquid and flow but remain in solid state
—results in formation of oil and natural gas
Transform boundary
- Strike-slip faulting- occurs when rocks slip horizontal along a vertical or near vertical plane
-strike: orientation of the fault plane with respect to north
-slip: the blocks of rock on each side is parallel to strike
—mid ocean ridges opposite: right lateral v left lateral, appears opposite because ocean crust is moving away from ridge sediments
Who first noticed transform boundaries are opposite in mid ocean ridges?
J. Tuzo Wilson
History of plate tectonics
- Alfred wegener brought together most evidence, but not widely accepted
- Couldn’t explain mechanism causing continents to move, no one believed him till after he died
- Technology helped
- Sub “Meteor” found mount range under ocean
- Maurice Ewing in 1947 found lava flowing in middle
- Harry Hess said it’s “seafloor spreading” (lava under crust makes magnetic: leaves south enters north)
- Scientists started accepting hypothesis
- Discovered polar/magnetic switch (leave north enters south)
- Used seafloor maps and patterns of magnetism to prove seafloor spreading indefinitely
- Ages of fossils: closer to ridge younger farther away older
- Thickeners increases farther from ridge
- Track earthquakes and volcanoes and find all by ridges
- Plate tectonics driven by convection
- Magnum comes up in center of plate: hot spots
- Now we know why they move…. new thinking and new hypothesis
Evidence of plate tectonics from Alfred wegener
- Pieces of earth fit together
- Same fossils near where they would fit together
- Glaciers tore up the ground the same way
- Mountain belt extends where they would’ve been connected
What all did sonar help discover
- Continental shelves
- Continental slopes
- Abyssal plains
- Mid ocean ridges
How did harry Hess know the seafloor was spreading
- Ridges in all oceans
- Heat is greatest at center
- Ocean floor less than 2mil years old, land 4 bil +
- Plates destroyed when converge underneath
Why did the rocks move and Pangea split apart
Due to magnetic lava leaving south and entering north
How far can we detect eartherquakes
700 km (here to philly)
What does earthquakes happening on a plane support
The idea that a plate is sliding underneath another
Who are plate tectonics driven by convention
- Heat transferred so hot crust rises, cools, then sinks
2. Warm “astenosphere” comes up and spreads out…. where they hit each other the cooler denser one sinks
Hawaiian islands related to magnum coming up at the center of plates (hot spots)
- Hawaii was a long change on a hot spot and ask the old moved new formed
- islands increase with age farther from the hotspot
- hot spot moved south between 81-47 mya @ speed of 4 cm/year! Whole island chain moved
Science is the best known evidence but….
It can change
Movement of plate causes
- Forms mountain ranges
- Determines plant-animal species
- Determines geological hazards (earthquakes and valcanoes)
Oceanic continental collision versus ocean ocean collision in converging plates
- Oceanic-continental collision: formation of ocean trenches along the boundary between the two plates; volcanic arcs can also be found parallel to the convergent boundaries due to melting of the oceanic plate
- Ocean-ocean collision: one oceanic plate is more dense forms volcanic island arcs
Minerals
Composed on elements
Minerals
Can’t be broken down further
- naturally occurring
- solid
- inorganic
- definite chemical composition
- definite Chrystal composition (can be very large or very small)
How are minerals identified by
Luster: metallic or non Hardness: scale “moes mineral hardness scale” Cleavage: how it breaks Taste Smell Magnetism
Relationship between atoms, minerals, elements, and rocks
- Atoms
- Elements
- Minerals
- Rocks
How definitive structure in a mineral relates to atom bonds
Definite structure of a mineral is based on atom bonds
Groups of minerals
- Silicates: most common (silicons and o2) group of minerals within the earths crust! Quartz,muscovite,biotite,and fieldspars
- Carbonates: co3 main component limestone and so important to dissolution
- Sulfides (s): involved in the formation of sulfuric avid which gets in mining waters
Rocks
Aggregation of minerals and of mineraloids
What process produces different kinda of rocks
Igneous- volcanic eruptions
Sedimentary- weathering
Metamorphic- heat and pressure
Magma versus lava
Magma: intrusive/plutonic, large crystals (cools slowly)
Lava: extrusive/volcanic, small crystals (cools fast)
Pegmatitic
Large crystals
Glassy vs vesicular
Glassy smooth
Vesicular kind of bubbles, Spongy
Mafic vs felsic
Mafic: dark colored, iron magnesium
Felsic: light colored, silicone, petassium sodium, aluminum
Felsic—>intermediate—>mafic—>ultra mafic
What determines rock type
Texture and composition
Ie garnet- intrusive (large crystals) felsic (light colored)
Know figure 4-12 on PowerPoint 3
It’s a graph
Texture
Based on How formed, environment, and composition
Ie igneous very strong because of interlocking christals (used for foundations) & good source of mineral resources
Process of sedimentary rocks
- Compaction and cementation of sediments
- Precipitation forms solution***
- Sediments created through erosion and weathering
- Sediments building blocks of sedimentary rocks
Erosion
Removal of sediments by wind, water, ice
- transported the deposited somewhere else
- cementation: glue back together
Types of weathering
Mechanical: freeze and thaw cycle
Chemical: hydrolysis (chemical breakdown due to water) or dissolution (dissolved in water)
Different compositions of sedimentary rocks
Clastic: Made from compaction and cementation of weathered rock fragments
Biochemical: made from compaction and cementation of something living
Chemical: made from precipitation which formed mineral Chrystal
Texture of sedimentary rocks
Breccia- rivers/streams
Conglomerate- rivers/streams
Sandstone- beaches
Shale- deep sea/lagoons
Small vs larger upsize and more vs less angular
Smaller sediment size and less angular=better sorting—>been in system long (older)
Larger sediment size and more angular=worst sorting—>younger/newer
Sedimentary chararacterisits
Porosity-spaces betweeen grains; measured by percent of open space
Permeability- how well connected the pore spaces are
Directions for checking porosity
- Pour water from your 100 ml cylinder into the 50 ml sample of rock/soil until the water is even with the top of the sample
- Look at cylinder, how much water left? Let’s say 83 ml
- So how many And ml poured?17
- What percent of 50 ml is that? 50/17=.35x100=35%
4.
Why are sedimentary rocks important
Contains things we want (shale contains oil natural gas, and ground water)
Shale
Compaction shale-weakly cemented add water turns back to articles
Cementation shale-strongly cemented ya gotta last it (in general shale is relatively weak)
Fossiliferous limestone
Dissolved through dissolution leaving caves behind, dimpled land, sink holes (Florida)
Protolith
The parent rock, the original rock before metamorphoses
Metamorphism….
Increases crystal size
Foliated vs non foliated
Foliated: has layers?
No foliated: nolayers?
Foliation: weak points along those planes
Index minerals
Help us determine what conditions metamorphic rocks formed under
Non-metamorphic—>low grade—>medium grade—>high grade
What determines texture in metamorphic rocks
Aligning minerals, accomplished through
- mechanically rotation grains
- recrystaliaion and platey minerals into orientation perpendicular to stress
Pros of non foliated in metamorphic
Slightly stronger
Grain size increases
Importance of metamorphic rocks
Marble (homes statues)
Schist weathered to turn into NC state soil
Rock strength in metamorphic rocks
Related to composition
Stress
Force per unit area measured in Newtons (N)
-measured in pascals (n/m^2 when m^2=area)
Strain
How the material responds
Can occur in two ways:
1 temp strain: called elastic deformation (think of bending a stick or stretching a rubber band NOT until it breaks) remove stress nd goes back to normal
2 perm strain: called plastic deformation and behaves in 2 ways we spoke about within the earth, brittle and ductile
How are rock structures formed
From strain due to stress faults, folds, unconfirmity
Hydrologic cycle
- Evap
- Recip
- Infiltration/run off
- Transportation
- Evapotranspiration (through vegetation)
Movement through cycle: surficial process
-responsible for erosion, transport, and deposition of earths materials
—-water,wind,ice
Glaciers today vs Pleistocene glaciers
Today: 10 % of earth
Pleistocene: 30% of earth
Basal sliding
Over water saturated ice and rock
Internal flow
Icessreams
Glaciersize
Can be several km thick:
Below: 60m deform “plastically”
Above is the”brittle zone”-where crevassesform
Loess
Wind blown silt, leaves cross beds
Mineral resources
Exceptionally important globally and regionally
Critical minerals and ores
-important in producing products and who’s restrictions have global economic consequences
Ores: industrially important metals minerals, mined fro ore deposits
Tailings: leftover minerals associated with the deposit and not needed
Economic concentration factor-in order for a deposit to be economically viable it must be abundant in the deposit; this is many times past its crustal abundance
Types of ore deposits
- Hydrothermal ore deposites
- Igneous ore deposits
- Sedimentary ore deposits
Mining and environment
- allows elements o be mobilie andmoved around the sphere
- Ores mined crushed and or smelted with other materials to produce molten substances where the element in Question can be separated
- release of lead (pb),chromium(cr), and mercury (Hg) can have dangerous effects
- once mined cant go back —-> affects water and produces sulfur dioxide gas and cant fix land
Heap leaching
New mining technique used to extract metals from oxide and low grade sulfur ores- they are crushed and spread with cyanide to release gold, or sulfuric acid to release copper
Biogeochemical cycles
-metal cycling through earths systems
Miningregulation
-General mining act 1872:establishes exploring for and mining resources on public land and acquiring regulation for the protection of mining claims
-Federal land policy management act 1976:updated the regulation of surfaceland to 1. Require permits and 2. Have an environmental assessment and 3. Reclamation of land once mining done
(however something new reared its ugly head…. an environmental conscious!)
The department of interior manages
- bureau of land management
- national park services
- fish and wildlife
—forest services is under the dept of agriculture
Mechanical weathering
Breaking down of rocks into smaller pieces
Types:
1. frost wedging- alternate freezing and thawing of water
2. unloading- exfoliation due to reduction in confining pressure
3. thermal expansion- alternate expansion and contraction due to heating and cooling
4. biological activity- plants and animals interactions
Chemical weathering
breaks down rocks through chemical reactions
- most important agent in chemical reactions is water (reasoonsible for transport of ions and molecules involved in chemical process)
1. dissolution- aided by small amounts of acid in water, soluble ions are retained in the underground water supply
2. oxidation- any chemical reaction in which a compound or radical loses electrons, important in decomposing ferromagesian minerals
3. hydrolysis- the reaction of any substance w water, hydrogen ions attacks and replace other positive ions
Soil definitions
- Strictly geological science points of view (compositional)
- ie 25% air 45% mineral mater 25% water 5% organic mater - Applied science (engineering) point of view
- can be removed without blasting
Soil formation
Soils are derived from the weathering of rock and the introduction of organic and inorganic materials
Soil formation is further altered/modified by soil organisms, what are the two types?
depending on proton of the bedrock
- Residual soil-parent material is the underlying bedrock
- Transported soil-ford in places on parent material that has been carried elsewhere and deposited OR the soil was modified elsewhere then transplanted
Soil fraction factors
- Climate- most influential control of soil formation, key factors are temp and precipitation
- Topography- steep slopes often have poorly resolved soils, optimum terrain is a flat to undulating upland surface
- Parental material time- amount of time for soil formation varies for different soils for
- Ending on geological and climatic conditions
- Organic process- organisms influence the soils physical and chemical properties as well as furnish organic matter to the soil
In what direction does soil forming operate
from the surface downward
Zones/soil horizons
Vertical layers of soil
1. O horizon- concentrated organic matter, twigs, leaves-dark brown/Black
2. A horizon- organic matter plus mineral debris
3. E horizon- zone of leaching or .eluviation”, light in color, fe oxides removed
4. B horizon- zone of accumulation, materials brought down from above
A. Bt: Argillic b clay enriched
B. Bk: Rich in calcium carbonate (CaCO3)
C. K: Mostly CaCO3, caliche
5. c horizon- altered “Parent material”
6. R horizon- bedrock
7. Hardpan- compacted layers: impermeable
Soil texture
Result of mix of
Clay (< .004 mm)
Silt (.004-.074 mm)
Sand (.074 to 2.0 mm)
Water content
Within the soil, pore spaces are filled w air or water
Saturated- completely filled pore space.
Unsaturated- partially filled pore spaces. Flow is fastest in middle as film thickens around particles
Soil taxonomy
classifies soils based on number of horizons, nutrient status, organic content, color, Nd climatic association
- Entisols: no horizon, development-young soils
- Aridisols: desert soils, los organics (gypsum, caliche, salt)
- Andisols: volcanic
- Oxisols: oxidized, tropical
Engineering properties of soil
Soil is composed of 3 states [solid (minerals/organisms) gas (air) liquid (water)
Plasticity
Water content
refers to the behavior of fine grained soils and the soils “plasticity index” dependent upon water content
liquid limit- above this amount of water soil behaves like liquid
plastic limit- above this amount of water soil behaves like a solid
between these two amounts defines the plasticity index,! Too small an amount and the soil can turn into liquid, (liquefaction) and if the index is large (>35%) it means the soil can expand and contract
Shrink
swell potential (gaining and losing water) refers to potential of soils to gain or lose water as a consequence of how much clay expansive soils clays such as montmorillonite, could expand up to 15% but even 3% hazardous
Soil strength
ability to resist deformation
Cohesion- ability of grains to stick together (water)
Friction- between grains and from density and weight of material above
Sensitivity
refers to how easily a soil loses strength due to disturbance (manmade or natural)
during Earthquake the tremors may shake water saturated soils and turn them to liquid,liquefaction
What two things do rate of erosion depend on
- Raindrop impacts
- Sheet flow (run-off)
A. Rills
B. Gullies
What is one of the most common pollutants?
Sediments
natural: dust bowl
Man made: pollution of soils
• organic chemicals (hydrocarbons, pesticides)
• Heavy metals (cadmium, nickel, selenium, lead)
◦ Smelting of copper, preparation of nuclear fuels
• Solvents
Bioremediation and soils as filters
Bioremediation allows for microorganisms to be introduced which use the pollution as food
Soils-sand and gravel can also filter out pollutants as they move through groundwater
How much of farmable land has been lost and in what time frame
1/3, most in last 40 years
Better farming processes
- No till agriculture
- Contour plowing
- Terracing slopes
Mass wasting
Down-slope movement of earth materials
Landslide statistics
25-50 deaths in the U.S. annually
Annual cost $3.5 billion
Natural and manmade
Slope form
- Cliffs (hard infuriated rock like granite)
2. Hills and valleys formed in weaker rocks and soils
Parts of a cliff
Free face-face of cliff
Talus slop-rock fall deposits at bottom or along edge of cliff
Three parts of hills/valleys
- Convex slope-where it starts
- Straight slope-middle where around 90 degrees
- Concave slope-at bottom where curves back horizontal
How is slope stability determined
By the ratio (safety factor) of
- resisting forces to
- driving forces
Safety factor scale
More than one: resisting forces are larger (may be stable)
Less than one, driving forces larger (unstable)
Examples of resisting and driving factors
Resisting:
- material shear strength
- Length of slip plane
- Thickness of overburden
Driving: -weight 0area of overburden -thickness of overburden -slope (angle)
Multiple all these numbers together then do decision
Mass waiting classification
Rotational (slow to fast) movement & rock and soil materials=slumps
Translational (slow to fast) movement & rock and soil materials=slides
Falls (fast) movement & rock and soil material=Falls (topples)
Falls (slow) movement & rock and soil materials=Creep
Flows (rapid) movement & rock and soil materials=debris flow
Flows (very rapid) movement & rock and soil materials=debris avalanche
Landslide causes:
Too much water
-reduces cohesion (remember liquid limit)
-mostly a natural process (precipitation); although increased urbanization leads to more pavement-hence-runoff!
Too much load (overburden)
-natural(from weathering/depositional process)
-manmade (from construction/road creation
Steeping the slope
-construction which removes material at the base of the slope
Minimizing/reverting landslide hazards
Identify potential hazard areas!
- land slide inventory
- land use considerations
2. Remove the water (drainage control) - surface drains
- drainage pipes at slope base
3. Grading (if done right) - reduces slope steepness
4. Electronic monitoring - using satellites and computers
Why do tungsten diamonds break?
-Tungsten carbide wedding rings, may have diamonds in them but the band is tungsten. The tungsten ring can be brittle because of the hardening process
Manmade diamonds often are created using combinations of nickel, cobalt and iron, and what soft mineral with carbon?
Cubic zirconia diamonds are made from zirconium dioxide-8.85 on mohs scale
How do coquina the rock and coquina the shell relate
- coquina is a rock composed of broken bits and pieces of shells
- coquina shell, is the most common name for the bivalve species Donax variability
- coquina comes from he Spanish word for “cockle” or “shellfish”
