GEOLOGY 101: FINAL
46 Cards in this Set
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Understandthe workings behind the scientific method. What are the different stepsand the balances and checks associated with the scientific method.
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Hypothesis
Gather data
Theory
Gather data
Scientific Law
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The Earth began to differentiate forming a stratified Earth. How does density change with depth? What are these zones (not necessary to memorize depths)? How are these zones (Fig 1.1) grouped to form the Geodynamo System and Plate Tectonic system? Which one makes up the tectonic plates…
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Density increases as you go further in depth. Outer and Inner Core, mantle, upper mantle, crust.
TheGeodynamo system controls the Earth’s magnetic field and reverses direction onintervals of tens of hundreds of thousands of years.
Asthenosphere.
The inner like core and mantle would b…
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How old is the Earth?
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4.53 billion years
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What is the theory of plate tectonics? What is the driving force behind plate tectonics?
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The Theory behind plate tectonics is The outer portion of earth is not continuous shell, broken into units. The plates move riding on the asthenosphere, most geologic activity such as earth quakes and volcanoes concentrated at plate boundaries, plate interiors less active.
Convection.
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What type of plate boundary do earthquakes occur at? What type of plate boundary do volcanoes occur at?
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All of them.
Convergent and hot spots.
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What are the three main types of plate tectonic boundaries and any subdivisions of each? What are the plate motions relative to each other? What are the stresses associated with each? Are there any features associated with these boundaries (mid-ocean ridge, trench, subduction zone, rift…
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Convergent - move towards each other, compression, volcanoes, subduction zone
Divergent - move away from each other, tension, mid-ocean ridge
Transform - move along each other, sheer, trench
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Identify the plate tectonic settings for real world examples of the different type of plate boundaries and hot spots (location or mountain range)? (Iceland, Mid-Atlantic Ridge, East African Rift, Red Sea, Cascade Mtn, Andes Mtn, Himalayas, Hawaii, Yellowstone, Aleutians Island Chain, Jap…
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Convergent - Cascade Mountain range, Andes, Himalayas
Divergent - Mid-Atlnatic Ridge, East African Rift, Red Sea
Transform - Gulf of California, San Adreas Fault
Hot Spot - Hawaii, Yellowstone
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What determines which plate will subduct?
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hot material rises due to lower density and coolmaterial sinks.
Continental crust is more dense.
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What are hot spots? Where would you find them? Do they create or destroy oceanic or continental crust? What feature/landform do you find above them?
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Stationary thermal plume burning through a plate.
Creates new continental crust
Island, geyser
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What is a mineral?
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Natural occurring inorganic crystalline solid with a specific chemical compound
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What are mineral polymorphs? What are the polymorphs of carbon? (as discussed in class)
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same composition but different crystal structure.
Ex. Diamond is the polymorph of graphite
Different crystal structure based on the depth at which they form
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What is the most abundant mineral group in the crust?
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Silica
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How are igneous rock formed? What are the two types of igneous rock? How does the location where they cool affect the speed of cooling and there crystal size?
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Formed by the solidification of molten rock or melt
Intrusive and Extrusive
Intrusive has bigger crystals from slower cooling, extrusive has smaller crystals from faster cooling
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Understand and be able to use (or recognize in slides) the following terms: plutonic, volcanic, intrusive, extrusive, aphanitic, phaneritic, porphyritic, pegmatitic, glassy, vesicular, pyroclastic. What does each texture indicate about the rate of cooling?
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Plutonic - Intrusive igneous rocks
Volcanic - Extrusive igneous rocks
Aphanitic - Crystalsare the finest
Phaneritic - all visible, corase grain
Porphyritic - Crystalsare too fine to be distinguished without a microscope
Pegmatitic - very large grains
Glassy - No minerals present
Ve…
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Be able to discuss any of the following: Mt. Rainier and Hawaii, in terms of the dominant landform (composite, shield volcano, flood basalt), eruptive style, composition of magma/lava, viscosity of magma/lava, type of plate boundary. Describe the volcanic hazards associated with Mt. Rain…
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Mt. Rainier - is a volcano formed at a convergent boundary, strato volcano, pyroclastic eruptive style, with low viscosity, felsic composition, lava flow
Hawaii - is formed on a hot spot, featuring shield volcanos, with a effusive eruptive style with high viscosity, magic composition
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What is weathering and erosion, how do they differ?
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Weathering - is the process by which rocks are broken down atthe Earth’s surface
Erosion – is the process that moves pieces of rock or weathering depositsthem elsewhere
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Be familiar with the different types of chemical (hydrolysis, oxidation, dissolution) weathering and physical weathering?
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Physical - jointing, frost wedging, root wedging, exfoliation
Chemical - Hydrolosis (water chemically reacts with mineral to break them down), oxidation (reactions in rocks transforming iron bearing minerals into rusty brown mixture), dissolution (minerals dissolve into water)
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What is sediment and where does it come from?
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Rocks form when fragments of all rock types (likesand, pebble or even fossils) are pressed or cemented together during burial,
The product of weathering is a sediment
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What are the 3 classes/categories of sedimentary rock and under what conditions do they form?
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Clastic - Cementation
Chemical - with crystalline structures
Biochemical - fossils
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For clastic rocks be able to recognize sorting and rounding differences? What do these textures indicate about the sediment transport distance? How is the sorting, rounding and size of particles affected by the agent of transport (wind, water, ice)?
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the more rounded the same size rocks the more well sorted it is, the more sorted the farther is traveled, wind transports the smallest, like first and sand, water can transport larger particles like pebbles, and ice can transport the largest particles such as boulders.
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What are sedimentary structures? Be familiar with the different types of sedimentary structures and what information they provide?
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Bedding - the layering of sedimentary rocks form during deposition
Graded bedding - large particles at the bottom, finer at the top
Cross bedding - can tell which way the wind blew
Ripple marks - form from ocean and water
Bioturbation - form from animal tracks
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How does sediment become a sedimentary rock? What is lithification?
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Sediments become sedimentary rocks through cementation and compaction, this is lithification
The processes by which loose sediment is hardened to rock are collectively
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What are the controlling factors of metamorphism?
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Temperature, pressure, fluids
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What are the main types of metamorphism (regional, contact, shock), where do they occur geologically and what type of plate boundary are they associated with them (if any)?
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Regional - occurs at great depths at a convergent boundary
Contact - Increasing heat happening at a subsections zone, a convergent plate boundary
Shock - associated with a meteorite
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What is foliation? What pressure condition is needed for its development? What other factor determines if a rock will develop a foliation? Will a limestone or sandstone parent rock develop foliation under directed pressure (and a high temperature)? Why or why not?
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Foliation is layering of minerals in rocks, great depths and high heat. Heat and pressure determine if a rock will develop foliation
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Know the difference between absolute and relative dates, and how they're determined.
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Absolute dates: Determined actual time;
Relative dating: Guessing by the rocks and stuff present around
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Know and understand(be able to apply) the principles of relative dating (original horizontality, superposition, cross-cutting relationships, etc)
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Superposition: oldest on the bottom, youngest on the top
Original Horizontality: all rocks start horizontally, but after time, they move to diagonal
Cross-cuttinh relations: Fault or dike go through
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Know each type of unconformities (each type), what do they represent and how they form.
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Disconformity: missing time; similar above and below, middle is missing
Non-conformity: a fault or a dike; intrusion that comes in is younger
Angular: Folded layers eroded and deposited on
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Geologic Time Scale: You DO NOT need to memorize all of it. You should know the names and ages of the Eons (Precambrian) and Eras (Paleozoic, Mesozoic, and Cenozoic). You should be able to put them in relative order from oldest to youngest.
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Be able to recognize all structures presented as a map or a cross-section view given the age relationship and strike and dip symbols of the units. Be able to name the type of structure (horizontal or plunging anticline or syncline, reverse or other fault types), the type of stress involv…
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Know the controlling force of mass wasting
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Gravity
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Know the important factors in mass wasting (earth material, water content, slope
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Nature of slope material: rocks and vegetation present
Water content: precipitation and nearby water sources
Steepness of slope
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Review the types and rates of movement (e.g., creep compared to rock avalanche)
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Creep - slow
Slump - intermediate
Rock avalanche - super fast
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Understand the different types of mass wasting and their causes
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Creep - Downhill movement of soil or other debris
Slump -
Rock avalanche -
Mud flow -
Rock slide -
Debris flow -
Debris avalanche -
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Know the effects of deforestation on mass wasting
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if you take out the trees, there is a greater chance of mass wasting
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Understand the difference in stability for rock layers – beds parallel a valley slope and those beds which dip into the valley wall.
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What are the triggers for mass wasting? Can human activity trigger mass wasting? How?
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Heavy Rain, Earthquakes, Volcanos, Human Activity
Yes, through removal of vegetation, increasing angle of slopes, and addition of water
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How do rivers and streams fit into the hydrologic cycle (run off verses infiltration)? What are the different water reservoirs? Be able to place them in order from largest to smallest.
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Rivers and streams run off into the ocean, then evaporation happens, then precipitation, then comes back down into rivers and streams.
Biosphere, Atmosphere, Lakes and Rivers, Ground Water, Glaciers and Polar Ice, Oceans
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How are materials transported in rivers and streams?
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Through Solution, Suspension, and Bedload
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What are stream divides and drainage basins?
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Basin - an area of land which funnels all the water into streams draining the area
Stream Divide - Ridge of high ground along which rain runs off one side or the other
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Be able to recognize the difference between stream channel types (straight, meandering, braided).
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Be able to recognize the different stream drainage patterns and what each tells you about the underlying rocks. (dendritic – flat lying or composed of similar materials, etc.)
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Dendritic - flat lying or composed to similar rock materials
Trellis - folded rock layers
Rectangular - rock units cut by joints or faults
Radial - high mountain peaks
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Describe how velocity changes within a meandering stream. How does this lead to the formation of point bars and cut banks? How do meandering streams change over time? How do oxbow lakes form? What are meander scars?
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Faster at the cut bank, eroding the land; slower at the point bar, depositing sediments.
By eroding and depositing into the land.
Oxbow form when meandering streams move really fucking far.
Meander Scar - where the water used to be, but there is no water
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Be able to use (and recognize units of) the following terms: velocity, gradient, discharge.
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Velocity - ft/sec
Gradient - ft/mile
Discharge - ft3/sec
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Recognize and explain how the following form: floodplain, levees, terraces, alluvial fans, deltas.
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Floodplain: If there was flood this is where the water would form; the lowest point
Levee - ridges of course materials built up during periods of flooding to confine the river within in its banks
Alluvials Fans - a gently sloping apron of sediment dropped by efemoral stream at the base …
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If a flood has a recurrence interval of 20 years, what is the % chance that this magnitude flood will happen this year? What about the next year? (This applies to 5, 10 or any flood event)
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5% this year and next year
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GEOLOGY 101: EXAM 2