Term
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Definition
| in an undeformed sequence, each layer is younger than the one beow |
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Term
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Definition
| sediments are generally deposited in horizontal layers |
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Term
| cross-cutting relationships |
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Definition
| features that cut rocks (faults/intrusive igneous rocks) must be younger than the rocks that they cut |
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Term
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Definition
| same number of protons, different number of neutrons |
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Term
| What is the atomic number of an element? |
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Definition
| number of protons (defines the element) |
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Term
| How do you calculate the atomic mass of an element/atom? |
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Definition
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Term
| What is meant by the half-life of a radioactive isotope? |
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Definition
| time required for one half of the atoms in the sample to decay (measures rate of decay) |
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Term
| What is meant by parent and daughter isotopes? |
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Definition
Parent = original
Daughter = new isotopes created by radioactive decay |
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Term
| How can we date minerals/rocks using isotopic dating? |
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Definition
| Amount of parent/daughter atoms measures amount of decay (half lives), from which we can calculate age |
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Term
| What two factors will determine the best isotopes you use to date a mineral/rock? |
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Definition
1) What is in the mineral you want to date
2) Age of material vs. half-life of isotope |
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Term
| What are the factors that make Radon dangerous to humans? |
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Definition
- Decay products get into lungs and release radiation as they continue to decay
- Odorless, not easy to detect
- Radioactive
- Seeps into basements |
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Term
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Definition
| large accumulations of undecayed plant material gets buried in oxygen-poor environments (typically forms in swamps) |
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Term
| What happens to coal as it gets buried more deeply? |
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Definition
- Amount of recognizable plant material decreases
- Water, oxygen, hydrogen decrease
- Relative amount of coal increases, gets blacker
- Coal burns hotter |
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Term
| How does oil form? And, what are the materials that form if the oil-forming organic matter is heated to higher and lower temperatures than those that form oil? |
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Definition
Partially decomposed organisms in marine setting are protected from decay by burial and lack of oxygen. Burial heats rock and converts organic matter...
> Into keragen (thick waxy substance made of hydrocarbon chains) at lower temperatures
> Into heavy and light oils at higher temperatures
> Into natural gas at highest temperatures |
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Term
| What types of biological material forms coal and what forms oil/gas? |
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Definition
| Coal forms from undecayed plant material, and oil/gas forms from partially decayed organisms |
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Term
What are three components needed to form an oil accumulation (pool)
explain each briefly? |
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Definition
1) Source rock - abundant organic matter
2) Reservoir rock - where hydrocarbons are stored, porous and permeable
3) Cap rock - impermeable rock to prevent upward migration to surface |
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Term
| What factors affect our estimates of remaining oil (reserves and resources)? |
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Definition
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Term
| What is an oil shale and what role will oil shales potentially play in oil exploration in the future? |
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Definition
- Contains kerogen, which when heated with water converts to petroleum
- 14x more resources of oil shale than conventional oil, may be used when oil supplies diminish |
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Term
| Where are the largest deposits of oil shales in the U.S.? |
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Definition
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Term
| What is a tar sand or oil sand? |
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Definition
| mixtures of clay and bitumen (highly viscous "tar" like hydrocarbon); production process is inefficient |
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Term
| Where are the largest deposits of tar sand located? |
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Definition
| Venezuela and Alberta, Canada |
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Term
| How can CO2 and other “greenhouse” gases produce long-term atmospheric warming? |
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Definition
| absorb long wavelength infrared rays and reflect heat back to Earth |
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Term
| How may burning of fossil fuels contribute to this warming? |
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Definition
| emits CO2, a greenhouse gas |
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Term
| What changes in atmospheric CO2 levels and global average temperatures have been measured over the past 100 years or so? |
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Definition
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Term
| What isotope is used in most nuclear reactors to produce energy? |
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Definition
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Term
| Explain what occurs when a Uranium atom is hit by a neutron in a nuclear reactor. What are the three groups of products of this collision? |
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Definition
It reacts and splits into:
- Two atoms of other elements
- 3 neutrons
- Energy (200 million electron volts) |
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Term
| How does this lead to a self-sustaining chain reaction that continually produces energy? |
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Definition
| Neutrons fly off and hit adjacent Uranium atoms and set off a chain reaction |
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Term
| What is meant by the “enrichment” of Uranium? |
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Definition
| addition of more fissionable Uranium to amount present when mined |
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Term
| What is the approximate “target” percentage of 235U that makes up a fuel rod that goes into a nuclear rector? |
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Definition
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Term
| What is meant by elastic deformation? |
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Definition
| returns to original shape when stress is removed |
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Term
| Along what type of boundaries may faults form? |
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Definition
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Term
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Definition
| shaking of the ground caused by a sudden slip along a fault surface |
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Term
| Explain the elastic rebound theory and how earthquakes occur in this model. |
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Definition
| elastic strain builds up without movement on fault, it ruptures suddenly and releases energy in form of seismic waves |
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Term
Explain stick-slip behavior of faults and why this is behavior is dangerous.
How is this different from fault creep? |
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Definition
Strain builds on locked fault for long period. When fault slips, releases a lot of energy
- More dangerous than fault creep b/c fault creep is slow, gradual, smooth movement, no seismic energy released |
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Term
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Definition
| point of initial rupture from which energy waves radiate out from (3D) |
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Term
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Definition
| geographic point on the earth's surface directly above the focus (2D) |
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Term
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Definition
| surface exposure of fault surface |
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Term
| Through what type of material can P waves travel? How about S waves? |
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Definition
P - Solid, liquid, or gas
S - Only solid |
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Term
| How do surface waves form? Where do you find them? |
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Definition
| Form when P & S waves hit earth's surface, find them only on surface |
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Term
| What type of waves behave like water waves? |
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Definition
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Term
| Which waves travel faster, P or S waves? |
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Definition
| P waves travel 1.7x faster |
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Term
| How can the velocity of P and S waves be used to determine the location of an earthquake? |
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Definition
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Term
| How do the Richter and Moment magnitude scales differ? |
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Definition
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Term
| What is the only state to have experienced several magnitude 8 or greater earthquakes? |
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Definition
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Term
| What is the difference between the Richter scale and the Moment magnitude? What does each measure? |
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Definition
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Term
| Explain how Tsunamis form and how they change as they move closer to shore. |
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Definition
| Movement of seafloor causes surge of water; low amplitude in open ocean turns into high amplitude when slowed by shallow water -- get taller |
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Term
| What are P- and S-wave shadow zones? How does the outer core affect the path that seismic waves travel through the earth? |
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Definition
| Areas that the waves do not travel through; cannot be detected on seismographs |
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Term
| What is the low-velocity zone? |
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Definition
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