Final (PPTs: Before Midterm) Flashcards
Skipped Intro Slides (Sept 6-13)
I.e…
- Remote sensing, GIS
- Principle of Superposition, Principle of Original Horizontality, Principle of Uniformitarianism (James Hutton, Hutton’s Unconformity) -> Principle of Actualism
Skipped Intro Slides (Sept 13-15)
I.e…
- Types of sciences
- Definition of model, flux, cycle, budget, feedback, residence time, sequestering, sink, source, etc…
- 1.74x10^17 Watts input from Sun (~30% reflected back to space, ~50% converted to heat an reradiated, ~25% melts ice and evaporates water to be stored in hydrosphere, rest 350tW goes to wind, waves and currents and more, and least amount ~40tW goes to living things)
- ~32 tW from Earth, breakdown of Uranium, Thorium, and other radioactive elements (volcanoes and hotsprings 0.3tW, undersea volcanoes 11tW, surface conduction 21 tW), conduction and convection
- Definition of geothermal gradient (more pronounced with depth, varies from place to place)
- ~27 tW from tidal energy (spring tides and neap tides, flood current and ebb current, twice daily tidal cycle)
- Energy consumed globally is 3x10^20 J (equivalent to 10 barrels of oil per person per year)
Skipped Intro Slides (Sept 15-18)
I.e…
- Hydrologic cycle (reservoir %: 97.5 oceans & 1.85 ice & 0.64 groundwater & 0.01 lakes and rivers and atmosphere, pathways, budget %s: 11% runoff diverted by humans, 26% of evapo-transpiration is from human dominated land)
- Residence time = size of reservoir / flow rate, typical residence times for resevoirs (thousands of yrs for oceans and icecaps, weeks for rivers, days for atmosphere)
- Rock cycle
- magma @ 800-1200 C and lava at ~20
- Definition of rocks, minerals, breakdown of 3 rock types.
Ch. 2 & 4 Slides (Sept 18-22):
What is the prevalent theory for the formation of the universe?
The Solar Nebula Hypothesis.
How long did it take to form the sun and what is the approx. composition?
10 million yrs to form sun.
74% H and 26% He.
What process converts H to He in the star?
Nuclear fusion.
What is the basic composition of the Terrestrial and Jovian planets?
Terrestrial: High temperature condensates of refractory elements such as Ca, Al, Mg, Fe and Si.
Jovian: Low temperature condensates of volatiles such as H, N, C, and He.
How old is the solar system?
~4.56 billion yrs old.
Beyond the end of the nebular hypothesis story, what five key factors played determining roles in the subsequent evolution of the terrestrial planets?
- Melting, Impacts, and Differentiation (Dense Elements Sink)
- Volcanism (Radioactive Elements)
- Planetary Mass (Orbit, Moons, Atmosphere)
- Distance From Sun (Water as Liquid)
- Biosphere (Biogeochemical Cycles and Atmosphere)
Briefly describe the objects in the solar system?
- 8 planets
- 5 dwarf planets
- ~170 moons/satellites
- comets and meteorites
What are the Terrestrial planets and describe them.
Jovian?
Terrestrial: Small, rocky, metallic, and dense. Mercury, Venus, Earth, Mars.
Jovian: Larger, less dense, gaseous. Thin, H rich atmosphere, liquid interior, denser rock core. Jupiter, Saturn, Uranus, Neptune.
How many stars are there in the milky way? How many galaxies in the universe?
200-400 bill. stars in milky way and >100 bill. galaxies in universe.
Describe the features and properties of the sun.
- Enormous mass of ionized gas/plasma.
- ~700,000 km radius
- 109x Earth’s diameter
- Mass ~2x10^30 kg
- 300,000x Earth’s mass
- 99.8% overall mass of solar system
- Density 1.4 g/cm^3
- 1/4 Earth’s density
Describe the layers of the Sun.
- The Core (site of fusion, 62% He and 38% H)
- The Radiative Layer (Energy from core moves by radiation)
- The Convective Layer (Energy moves by convection)
- The Photosphere (Visible portion that emits light)
- The Chromosphere (A low-density layer of very hot gas)
- The Corona (Even lower density layer of gasses)
What is the distance between Sun and Earth? Earth and Moon?
~150x10^6 km (1 AU)
~315x10^3 km
What is the Sun’s total energy output? What reaches Earth?
- 8x10^26 W
1. 8x10^17 W
What is the max energy flux on Earth’s surface?
1370 W/m^2 with sun directly overhead.
Fusion converts matter to ___. Energy released by fusion in the Sun is in the form of ___ ___ (98%) and neutrinos.
Energy. (E=mc^2) Gamma rays (98%) and neutrinos.
Describe to P-P cycle (88%, CNO 12%).
- 4H==>1He + E
- Extreme temperatures needed (Core sun is 15,000,000K)
- 4.2x10^-12 J from one reaction
- 4.5x10^6 metric tons of H->He every sec.
Most solar energy has a wavelength of 10^-5 to 10^-7 m. This includes…?
- radio
- infra-red
- visible
- UV
What is a spectrum?
A group of electromagnetic rays in order of increasing or decreasing wavelength.
Why is the solar spectrum not a perfect blackbody?
H surrounding sun absorbs as does Earth’s atmosphere.
What planets are visible?
Up to Saturn, rest need a telescope.
Give some features of Mercury.
- smallest planet
- closet to the sun
- no moons
- goes around the Sun fastest, 59 earth days
- D: 5430 kg/m^3
Give some features of Venus.
- 2nd planet from the Sun
- Inside is very similar to the earth
- Covered with clouds
- 10-30 km thick crust
- brightest in sky
Give some features of Earth.
- Crust thickness: 30 km avg. for land, 5 km avg for seabed
- D: 5520 kg/m^3
Give some features of Mars.
- 4th planet from the Sun
- One-half diameter of Earth
- Rocky and metal
- D: 3940 kg/m^3
- Clouds and winds
- Red because of Fe rich material blown by wind
Give some features of Jupiter.
- 5th planet from the Sun. The largest planet
- H & He
- No hard surface
- Beneath the cloud layers, the clear atmosphere is denser and warmer and slowly transforms from a gas to a liquid without a sharp boundary
- Core: ~20,000 degrees Celsius
Give some features of Saturn.
- 6th planet from the Sun
- It has a famous ring- made of chunks of ice and rock.
- Exterior is composed of frozen ammonia
- Interior is composed of mainly H.
Give some features of Uranus.
- 7th planet from Sun
- Poles face the sun
- Blue due to methane
Give some features of Neptune.
- 8th planet from the Sun
- H, He, and methane
- Largest core, proportionally
- Blue color comes from methane
- Strongest winds (2000 km/h)
How is a planet defined?
- Orbit Sun
- Spherical Shape
- Cleared orbital path
What are the dwarf planets?
Pluto, are Eris, Haumea, Makemake, and Ceres.
Over what period does the Earth’s axis vary? Precession of equinoxes? Eccentricity of orbit?
- Tilt varies from 21.5 to 24.5 over 41,000 yr period
- 23,000 yr
- 100,000 yr
Skipped Some Slides (Sept 22-25)
Equations for period, etc…
Skipped Some Slides (Sept 25)
Atomic numbers, mass, radioactive decay, half-life equations.
What is the half-life of Carbon 14 (to N 14)?
5,730 yrs.
Organic matter, calcium carbonate, fossils, wood.
What are some principles of stratigraphy?
- Principle of original horizontality
- Principle or superposition
Lithology (layers) and fossils can show correlations. Cross cutting relationships can also show relationships, such as igneous intrusive (xenoliths, etc…), faults and unconformities. Name the unconformities.
- Nonconformity
- Angular unconformity
- Disconformity
Briefly describe the eons in the geological time scale.
Hadean (>3.8 Ga): earliest known rocks, molten earth, differentiation.
Archean (2.5-3.8 Ga): atmosphere mainly N and CO2, first evidence of life.
Proterozoic (543 Ma - 2.5 Ga): tectonic similar to today, single-celled organisms abundant, increasing O.
Phanerozoic (0-543 Ma): first animal shell fossils (542 Ma), increased animal diversity, land colonized by plants (400 Ma), first land animals (insects, amphibians), Pangea.
What was the atmosphere like in Hadean eon vs now?
Now: -O 21% -N 78% -CO2: 380 ppm Then: -Oxygen: little -Nitrogen: similar -CO2: uncertain, likely high
How old are the earliest known rocks?
~4.0 Ga, metamorphic
When was the first evidence of life?
3.5 Ga.
Microfossils, stromatolites.
What were the first animal to develop shell to protect from predators?
Trilobite.
Describe the Mesozoic era.
- starts at major extinction event ~250 Ma
- Pangea split by rifting
- Dinos
Describe the Cenozoic era.
- starts at major extinction event ~65 Ma
- rise of mammals
- first humans ~3Ma
- major glaciations in last 2 Ma
Define rocks vs minerals.
Rocks: naturally occurring mixtures of minerals
Minerals: naturally occurring, inorganic, with a repeating atomic structure (crystalline)
What are the two characteristics that best allow the study of minerals?
- Crystal structure
- Composition
What are the abundant elements in the Earth? The crust?
Earth: Iron (35%) Oxygen (30%) Silicon (15%) Magnesium (13%) Crust: Oxygen (46%) Silicon (28%) Aluminum (8%)
What are the rock forming minerals?
Si and O with the six metals (silicate minerals)
Skipped Some Slides (Oct 2-4).
Atoms, electron shells, bonds (ionic, covalent), ions, mineral properties,
What is Moh’s relative hardness scale?
It has 10 harnesses that are not at equal intervals. I.e. Diamond 10, Talc 1, fingernail 2.5, penny 3,5, glass 5.5.
What are silicate mineral?
- Largest group of minerals
- Si and O form strong covalent bond
- Arranged in Silica tetrahedron
- I.e. quarts, feldspar, mica, ferromagnesian minerals
Describe quartz.
- SiO2
- most common single mineral
- several varieties are semi-precious stones
Describe feldspar group.
-most abundant mineral group in crust.
-contain modified silicate tetrahedral with Al
-also contain K, Na or Ca
Na-Ca feldspar is called plagioclase
Describe Mica and clay minerals.
Mica -arranged in sheets -splits easily, basal fractures -white (K, Al-rich) to black (Mg, Fe-rich) Clay -sheet silicates, products of weathering -fine-grained typically
Describe ferro-magnesian minerals.
- Fe 2+ and Mg 2+ have ~same size and same charge, so fairly interchangeable
- most green or black
- main constituent of mantle is Olivine mineal
What are some non-silicate minerals?
calcite, sulphide minerals, iron oxides, gold, diamond
Describe carbonates.
- CO3 2-
- Calcite CaCO3
- Effervesces with acid
Describe Sulphides and Oxides.
Sulphides -metal + sulphur -Pyrite FeS2 -Galena PbS Oxides -metal + O -Magnetite Fe3O4 -Hematite Fe2O3
Partial melting in the ___ adds material to the crust.
Asthenosphere.
At Earth’s surface, when do rocks begin to melt?
800˚C-1000˚C, complete melting happens by 1200˚C
How does pressure and water presence influence rock melting?
Greater pressures occur with depth and cause rocks to resist melting.
Presence of water dramatically reduces melting temp.
Skipped Some Slides (Oct 6-11).
Four igneous settings, types of intrusions, volcanic styles, volcanic hazards.
What is the most abundant element in igneous rocks?
O.
Also most abundant component of lithosphere. Universal acceptor. Silica component also extremely common (73.9%).
Describe felsic rocks/magma. (Extrusive rhyolite and intrusive granite)
- Silica rich (>70%) magmas & rocks
- Typically formed by melting of the crust
- Viscous magma
- Solidify at relatively low temperature 600-900°C
- Abundant quartz and Kfeldspar
- Pale colour
Describe intermediate (in terms of felsic) rocks/magma. (Extrusive andesite and intrusive diorite)
- 50-70% SiO2
- Typically formed at depth in subduction zones
- Intermediate properties
- Moderate viscosity
- Solidify at intermediate temperatures
- Ferromagnesian minerals, Na and Ca feldspar
- Little or no quartz
- Grey colour
Describe mafic rocks/magma. (Extrusive basalt and intrusive gabbro)
- 45-50% SiO2
- Typically formed by partial melting of the mantle
- Low viscosity
- Solidifies at >1000°C
- Forms rocks that have abundant ferromagnesian minerals
- Ca-feldspar
- Dark colour
Describe ultramafic rocks/magma.
- <45% SiO2
- Mantle is ultramafic rock
- No ultramafic magmas erupted at present day
- Ultramafic magmas may have existed in early Earth
- Entirely ferromagnesian minerals
- Little or no quartz or feldspar
A fragment of hot, shattered magma or any other fragment of rock ejected during an explosive eruption is called…?
Pyroclast. Unconsolidated pyroclast is called tephra.
Pyroclastic rocks are also called ___ rock.
Volcanoclastic.
Stratovolcanoes are caused by which composition of magma?
Andesitic.
Skipped Some Slides (Oct 13-18)
Weathering defn, erosion defn, regolith defn, soil defn, erosion products, lithification, differential stress, slate, schist, gneiss.
What are some forms of mechanical weathering?
– Frost action – Abrasion – Pressure release – Biological effects – Daily temperature change?
What are some forms of chemical weathering?
– Gases from the atmosphere
– Water
– Minerals
Chemical weathering of silicates (hydrolysis) produces what?
New clay mineral.
Minerals that crystallize at ___ temperatures are less stable and more prone to chemical weathering.
High.
Clastic sediments are the solid products of weathering. Name some.
– Coarser than 2mm: Gravel (conglomerate rock)
– Finer than 2 mm but coarser than 1/16 mm: Sand (sandstone)
– Finer than 1/16 mm but coarser than 1/250 mm (4 μ): Silt (siltstone)
– Finer than 4 μ: Clay (claystone)
– Silt and clay are collectively: Mud (mudstone, shale)
What are angular conglomerates called?
Breccia.
Beach environments are characteristic of…?
Lack of feldspar and olivine, well sorted and rounded minerals. Due to the constant motion of the water, back and forth. (Olivine and feldspar are very susceptible to mechanical weathering).
What are potential conditions for oolite rocks? (Non-clastic: Carbonate sediment, CaCO3)
Lagoons.
What are some Non-clastic evaporate deposits (deposited when sea-water evaporates)?
– Calcium and sulphate ions: gypsum – Sodium and chloride ions: rock salt (Halite NaCl)
What is the soil form of coal? (Non-clastic: organic)
Peat, plants not completely decayed?
What are some factors affecting rocks at depth in the crust?
- Temp
- Pressure
- Differential stress
- Fluid content
- A few others
In the geothermal gradient, how much does the temperature rise for each 1 km of depth?
~25 degrees C.
Describe the properties of pressure.
– Measures force per unit area – Acts equally on all surfaces – Acts to reduce volume – Increases with depth – a.k.a. • Uniform stress • Hydrostatic stress • Confining pressure
Under differential stress, does quartz alter easily? Mica?
No and yes.
What causes fabric?
Differential stress.
What are the different types of metamorphism?
- Contact (metamorphic aureole)
- Burial metamorphism
- Regional metamorphism (typical of mountain belts)
Classification of metamorphic rocks is based on…?
- rock texture
- mineral assemblage
What are metamorphic rocks without fabric?
-Quartzite and marble.
What are the definitions of low-grade and high-grade metamorphism?
– Low-grade: 150˚C–550˚C and low pressure
– High-grade: above 550˚C and high pressure
What is metasomatism?
When there are abundant pore fluids involved in metamorphism.
What is the term for planar fabric? Stripey pattern/bands.
Foliation, gneiss.
The processes that result from changing temperature and pressure are either …? or both.
MECHANICAL DEFORMATION or CHEMICAL RECRYSTALLIZATION
What is the division of the earth by physical properties? Chemical?
Physical: Atmosphere, hydrosphere, lithosphere, asthenosphere, mesosphere, outer core, inner core.
Chemical: Atmosphere, hydrosphere, crust, mantle, core.
What are the differences in the chemical composition of the crusts?
Continental:
Less dense with more silicon and aluminum
Oceanic:
More dense with iron and magnesium
Skipped Some Slides (Oct 20-23)
Moho discontinuity, history and people for plate tectonics, 3 types of plate boundaries; convergent (destructive), divergent (constructive, transform faults (conservative), volcanic arc, convection plate tectonic models (3 mentioned).
The lithosphere is divided into how many plates?
9 major and several smaller.
How quickly do plates move?
A few cm/yr.
Describe mid-ocean ridges.
Several thousand km wide, rising 2 or 3 km above surrounding ocean floor.
Spreading centres typically occur beneath oceans. What is an exception?
Iceland.
What is a continental suture zone?
Marks the final disappearance of an ocean basin, forms spectacular mountain ranges.
Where are deep earthquakes usually generated?
Benioff zones.
How deep are ocean trenches?
Up to 11 km.
What are dextral transform faults? Sinistral?
Dextral: Right-lateral.
Sinistral: Left-lateral.
