GEOL 101 Final

Uniformitarian

• James Hutton (1726-1797) • "the present is the key to the past" Geologic processes occurring today are are/were responsible for shaping all landscapes on Earth Erosion and deposition are slow, Earth must be OLD

Chemical Weathering

- Dissolution, hydrolysis, oxidation - Dissolution of limestone - Acidity created by CO2 causes dissolution of calcium carbonate

Plate Tectonics Evidence

- Earthquakes - Volcanoes - Topography/relief - Age of crust - Seafloor spreading

Erosional Feature: Valley Shape

- Rock type and landscape features give evidence of tectonic and geomorphologic processes at work § Type of weathering (chemical, physical) § Agents of erosion (water, wind, glaciers, gravity) - Underlying assumptions to interpreting a landscape? § Using what we know about weathering and erosion to interpret the landscape - Assumptions § Some rocks erode more quickly than others §Sediments sizes or geographic patterns are associated with specific methods of weathering/erosion The world must be REALLY OLD

Steno (1638-1686) (just after Galileo, same time as Newton)

- Use observations of sedimentary rock layers - Developed relative age dating laws - Chronological order of events in sedimentary rocks

An igneous rock can become a sedimentary rock through the processes of: a. Erosion and deposition b. Cooling and crystallization c. Decompression and melting d. Heating and recrystallization

A

Evidence that Earth is more than 4.5 billion years old comes from: a. The dating of meteorites b. The study of historical documents c. Calculations based on Earth's cooling rate d. Measuring the thickness of sedimentary rock layers

A

Over time, Earth's interior is: a. Cooling off b. Heating up c. Gaining and losing the same amount of thermal energy each year d. Cooling off during some periods of Earth history and warming up during others ???????

A

No cap rock?

Oil seeps, tar sands - exposed to oxygen, oil degrades to bitumen/tar - unconventional oil source

Greatest Hazards in Pacific rim and Mediterranean:

"The Ring of Fire" - Pacific Ocean Rim- 80% if all earthquakes - Convergent boundary: subductions occurring

Beneficiation

(benefit to mining process, last step) - Iron oxide + carbon --> iron + carbon dioxide 2Fe2O3 + 3C --> 4Fe + 3CO2

Elastic Rebound Theory

(see pic 4) Stress increases until it exceeds rock strength, then movement occurs

How does land jump with an earthquake?

(see pic 5)

Movement of seismic waves away from focus

(see pic 7)

Types of Magma*******ON THE QUIZ

(see table 1) ---Water has a low viscosity, syrup has a high viscosity

Exploration

(see the pp) Need this information to decide where to mine, in what direction to mine, what technique is necessary, and the extent of the ore body! Complete"noninvasive"depthstudiesusingseismic exploration

Water flow in a confined aquifer

(think of the long tube and putting water in it and then lifting the tube on one side, etc) - Confined: impermeable boundary separates water from surface § Elevation of water table determines flow: downhill § Pressure of water determines flow: high to low § Flow velocity determined by pressure, elevation and the hydraulic conductivity of the aquifer (permeability)

Cross-cutting relationships also works with igneous intrusions

(where lava has intruded into pre-existing rock)

Continental rift zone

(young plate boundary)- this would be the beginning of a new ocean

Correlating rock units at a distance*****

*****

Reservoir size and residence time

- A reservoir will grow if input exceeds output - A reservoir will shrink if output exceeds input - The amount of time a resources stays in a given reservoir can be calculated if the system is in steady state (e.g., if input and output are equal) § Time=(reservoir size)/(input) AND/OR § Time=(reservoir size)/(output) - If the system is not in steady state, then reservoir size changed and residence time cannot be accurately calculated

What is a hot spot?

- Anomalously hot area in the mantle- hotter than any other place in the mantle around it - Hot = less dense, rises very quickly- heat rises - Causes depressurization melting- it does not turn into a liquid until it rises up very quickly

Water sources: Surface and groundwater

- Are the same? ... or at least connected! - Precipitation falling on watershed: - Surface run-off- water that ends up going on the surface and then runs along the surface - Infiltration - Evapotranspiration - Boundary between basins is a drainage divide Link in pp

Anticipating Earthquakes

- By keeping track of the number of earthquakes that occur along a fault, scientists find areas where stress may be accumulating ----Areas where no movement occurs are building up in stress

Why is CO2 important to temperature?

- Co2 can trap infrared energy (from Earth) § It vibrates because of the molecular structure § Solar radiation is short wave radiation Earth radiation is long wave radiation

Water flow in a confided aquifer

- Confined impermeable boundary separates water from surface - If we pumped the middle well so that the total height of water in the recharge area sank to the lower red line, what would happen to the water levels in the other two wells? All the wells water levels go down to the bottom red line

High and low gradient streams

- High gradient: steep, high-energy, less discharge § Erosion dominant § Large sediments (e.g. sand) transported - Low gradient: low-energy, more discharge § Deposition dominant § Only smallest sediments (e.g. clay) transported - What is discharge?

Mining Lab- hydrothermal fluids and cut off grade

- Hydrothermal fluids don't have to flow downhill- these are fluids that may have been part of the ground water but it came in contact with magma and then it could have been moving up because of the density change, so it would move the easiest way (to the permeable area- faults)- they typically move away from igneous rocks and towards cooler sedimentary rocks - Cut-off grade rising (e.g., 0.6 to 1%): cut off grade is the break even point for a business , if my grade is less than this I am not going to mine it, you have to have more for it to be profitable § Need a higher percentage in the ore to make it profitable § Monetary value of resource is decreasing § Extraction/beneficiation costs are increasing □ Remediation costs to fix the land make it much less profitable - Cut-off grade falling (e.g., 1% to 0.6): § Need a lower percentage in the ore to make it profitable § Monetary value increasing, costs decreasing The resource becoming more necessary, new technology

Difference in water supply over time

- Increases in population: there are more demands on water, the more creative we have to be about getting water to us and using it effectively § Over-pumping causing saline water intrusion in groundwater □ Link on pp § Over-pumping of groundwater can cause your neighbor's water to stop flowing or change directions: link in pp § Greater use than rainfall for surface water supply: link in pp - Changes in land use: § Contaminants from power plants in groundwater: link in pp § Contaminants from chemical plants in surface water: link in pp Contaminants from pig farming

Minerals Must Be...

- Inorganic: not alive and never has been alive - Solid: you can have magma but it is a mixture of a bunch of minerals, not a mineral. Melting the penny example, you would have molten copper if you melted it. - Crystal Structure: figure out how it is bonded and forms, crystals need time to grow, obsidian is something that is rock but not a mineral because the atoms didn't have time to form in a certain way - Defined Chemical Composition (linked to crystal structure): formula such as H2O - Naturally Occurring

The climate change debate

- Is climate change occurring?- this is not the question - How are anthropogenic inputs contributing to climate change? - What is the time frame during which changes will be seen? - What is the magnitude of the changes that will be seen? How will these changes/timeframe impact Earth's hydrosphere, biosphere, etc?

What do we need to make oil or coal

- Low oxygen Conditions - Heat - Pressure Organic Matter

Table 1*****

- Mafic- Source: mantle § Decompression melting § Hot spots and divergence § Creates shield volcanoes - Felsic- Source: crust § High temperature melting § Subduction and/or tectonics Under continental crust

The "Iron Age"

- Melting point: 2800 degrees F (1538 degrees C) This lead to the development of the blast furnace

Long term climate cycles

- Milankovitch cycles - Position of ocean basins and continents - Precession: 23,000 year periodicity - Eccentricity: 100,000 years - Axil Tilt: 41,000

Common elements and common minerals

- Minerals are comprised of elements - Eight elements make up the majority of Earth's crust and mantle: § Elements in the crust Mass% Oxygen (o) 46.6% Silicon (Si) 27.72% Aluminum (Al) 8.13% Iron (Fe) 5% Calcium (Ca) 3.63% Sodium (Na) 2.83% Potassium (K) 2.59% Magnesium (Mg) 2.09%

Mineral Resources

- Minerals or rocks mined from Earth and used in products we use - Defined by human usability- smart phone minerals were not useful a while ago - Actual rock or mineral: § Halite (rock salt), granite or marble (rock slabs), sand or gravel (for concrete) - Mineral commodities: § Processes to extract a specific element □ Bauxite (aluminum ore) □ Hematite (iron ore) Galena (lead ore)

Projected global temperature based on radiative forcing

- Mitigation- have to add less than we are now in order to reach that goal - Stabilization- having a cap at that number - None- no policy of changing CO2 abundance

Finding mineral resources

- Not equally distributed over the crust - Tectonic history can help identify where rare minerals are concentrated - Specific rock types and/or processes can concentrate minerals

Rocks containing iron are not all iron ore

- Ore § Elements incorporated into silicate rocks: difficult to extract § Silicate rocks are not typically ore □ Feyalite: (even if the iron content was the same) much harder to get Iron out of this Hematite- way easier to get Iron out of this

How Seismic Waves are Recorded

- P Waves: fastest- primary - S Waves: secondary - Gap between P- and S- waves indicates distance of seismic station from earthquake- the longer it goes the bigger the gap is going to be, two drivers driving to NYC at 80mph and 55mph

Solar

- Photovoltaic: (sunlight --> electricity) - Thermal (sunlight --> mechanical --> electricity) - Passive (sunlight --> heat)

How often will a flood occur?

- Recurrence Interval (R ) is equal to number of years on record (+1), divided by the magnitude (M) of the event § R=(N+1)/M - Magnitude= ranking of discharge (1=highest) within record Rank flows (1=highest)

Flooding probability

- Recurrence interval ( R): How often would you expect a flood of a specific magnitude to occur in a given amount of time? ----Magnitude = size of flood event

Flooding Lab

- Recurrence interval of 100 years- measurement of probability, this is like rolling the dice, every year you have that same chance § P = 1/R: probability = 0.01 (1% chance per year) What used to be a 100-year flood now a 1-year flood- reason paving everything (urbanization)- a lot more being diverted in the surface layer

Renewable vs. Non-Renewable

- Reservoir § Atmosphere § Ocean § Plants/Life § Earth - Flux § Respiration §Photosynthesis

Aquifer materials

- Sedimentary aquifer- groundwater storage between grains and sediments- Sandstone aquifer - Sedimentary aquifer- groundwater storage in solution cavities- Limestone (karst) aquifer

Oil Migration: How can we trap oil?

- Synccline- think of a sink (shaped like a U) Anticlline- good ay trapping oil (shaped like a shield volcano)

Beneficiation: Tailings

- Tailings often pumped into impoundments called trailing ponds § Usually downhill from the mill § Can be thousands of acres in extent and a few hundred feet thick § (video on pp) □ Arsenic, selenium, mercury, lead Often impurities associated with ore rock

Defining energy

- The ability to do work (force times distance) § Potential Energy: stored energy □ Chemical, nuclear, gravitational, mechanical (e.g. elastic) § Kinetic: energy of motion of waves, electrons, atoms, molecules, objects... Thermal, electric, radiant, sound, mechanical (e.g. motion)

Divergence Features

- Uplift/doming - Rifting - Formation of new oceanic crust - Mid-ocean ridge and passive margins

Review of surface water

- Water flows downhill - All water that drains to same "downhill" spot is in the same watershed - The volume of water per time flowing through a creek or river is discharge - Water flows downhill faster when the slope is steeper (high gradient) - Discharge increases as you move from high to low gradient - If discharge exceeds the river's capacity (flows out of channel), then a flood occurs

What parameters are important to include in climate models?

- solar irradiance (even though it is not very correlated) - big events such as volcano eruptions - other green house gases - ocean currents that change climate on a global scale - population - tectonic movement

How much of the total water on Earth is fresh surface water?

0.0027%

What is the primary magma forming process in this location? (see pic *)

1. Decrease in pressure 2. Increase in water content 3. Increase in temperature

If 154 gallons/day/person are used, how many gallons per day are used by carrboro and chapel hill residents?

12,096,150

Every American Born Will Need...

2.96 million pounds of minerals, metals, and fuels in their lifetime

An element "Z" has a half life of 1000 years. A volcanic rock created when lava cooled 3000 years ago had 200 atoms of "Z" in it. How much "Z" is left? - A. 100 atoms - B. 50 atoms - C. 25 atoms - D. 12.5 atom

25 atoms

Tollund Man

350 BC; discovered in 1950 in Denmark mummification because of peat Low oxygen = low ability to decompose organic matter

200 meters per second Pyroclastic Eruption at:

447 miles per hour § Duke (~10 miles) □ Pyroclastic flow would hit us in 1 minute 20 seconds § Greensboro (~50 miles) □ 6 minutes 42 seconds § Charlotte (140 miles) 18 minutes 48 seconds

Cyanide solution dripping onto gold ore Gryphon Gold Corporation: • 529,726 tons placed on the pad in fiscal 2012 • 6,409 recoverable ounces of gold • What percent grade is this gold ore? • Units of ore and gold must be in same units to calculate a percent! • 2000lbsinaton,16ozinapound(lb)

529,726 tons x 2000 lbs/ton x 16 oz/lb = 1.695 x 1010 oz ore (6409 oz / 1.695 x 1010 oz) x 100 = 0.0000378% grade!

• An element "X" has a half life of 10 years. • Originally, there were 1,000 X atoms • After 40 years pass, how many will there be?

62.5 atoms

(MAKE SURE TO CHECK IN SYLLABUS FOR THE CHAPTERS THAT ARE ONLY PORTIONS)

:)

A geologist examines a layer of sedimentary rock strata that contains pebbles of granite. From this, the geologist could infer that: a. An older layer of granite is below the sedimentary rock b. An older layer of granite is above the sedimentary rock c. A younger layer of granite is below the sedimentary rock d. A younger layer of granite is above the sedimentary rock

A

A group of geologists are on a research cruise to collect samples from the East Pacific Rise. What types of rocks are they most likely to find? a. Young basalts b. Ancient granites c. Thick layers of gravel, sand, silt, and clay d. A mixture of young and old intermediate rocks

A

A satellite map of the ocean floor reveals a linear chain of seamounts extending westward from volcanic islands. The seamounts increase in depth toward the west, away from the islands. The chain of seamounts and volcanoes can be used to infer: a. The motion of tectonic plates over a hotspot b. The location of an incipient subduction zone c. The line of a future spreading center d. The transform boundary between two ocean plates

A

After measuring the magnetism of thousands of rock samples of different ages from around the world, geologists discovered that: a. Earth's magnetics poles switch every so often b. Earth's magnetic poles rotate steadily from north to south c. The existence of Earth's magnetic field is a relatively recent phenomenon d. At some times in our planet's history, Earth has more than one set of magnetic poles

A

Alfred Wegener's hypothesis that continents move across Earth's surface was based on which piece of evidence? a. The shapes of continental coastlines b. The distribution of earthquake zones across the globe c. The pattern of magnetic anomalies on the ocean floor d. The location of volcanoes with respect to deep sea trenches

A

An accretionary wedge is: a. An arc-shaped array of volcanoes b. A collision zone between two continents c. A slab of lithosphere beneath a continent d. A body of sediments scraped off subducting crust

A

An igneous rock intrudes into three tilted layers of sedimentary rock. Which set of relative dating methods is most useful to determine the chronological order of formation of the rocks? a. Law of superposition, cross-cutting relationships, and law of original horizontality b. Law of original horizontality, rule of original lateral continuity, and rule of inclusions c. Rule of inclusions, law of superposition, and cross-cutting relationships d. Law of original horizontality, rule of inclusions, and law of superposition

A

Based on the analysis of GPS data and sampling of ocean crusts, a typical rate of seafloor spreading is: a. 5 cm/year b. 5 cm/thousand years c. 5 cm/million years d. 5 cm/billion years

A

How does the principle of faunal succession allow geologists to correlate rock strata in different geographic locations? a. It states that layers of rock strata at different locations can be correlated according to the unique set of fossils they contain. b. It states that fossils within rock strata are mostly homogeneous, suggesting that rock strata throughout a region should reveal similar sets of fossils. c. It states that the fossils in rock strata are older than the rock layers, allowing geologists to link younger and older layers across a region. d. It states that the evolution of fossils in one region should correlate with the evolution of fossils through different rock strata in another region.

A

Layer 5 is not seen in the left-hand diagram. This means: A. There is an unconformity between layers 4 and 6 in the left- hand diagram B. Layer 4 is younger than layer 6 C. The rock in layer 6 in the left-hand diagram must be older than the rock in layer 6 on the right-hand diagram D. Layer 4 and layer 5 are actually from the same time period

A

Plate tectonics formed the Atlantic Ocean over the course of 180 million years. How does this span of time compare with the entire span of geologic time on Earth? a. It is about 4/100ths of the span of geologic time on Earth. b. It is about 30,000 times the span of geologic time on Earth. c. It is about one millionth of the span of geologic time on Earth. d. It is impossible to compare to the entire span of geologic time on Earth because geologic time is infinite.

A

The Mohole Project (1958-1966) was a failed attempt to drill a hole all the way down to the Mohorovicic Discontinuity, or Moho. What would a core down to the Moho have included? a. An entire section of crust, all the way down to the crust-mantle boundary. b. An entire section of lithosphere, all the way down to the asthenosphere-lithosphere boundary c. An entire section of both crust and mantle, all the way down to the core-mantle boundary d. An entire section of crust, mantle, and outer core, all the way down to the boundary between the inner and outer core

A

The Pacific Ring of Fire is a chain of volcanoes associated with: a. Subduction of oceanic lithosphere b. Shear stress along major transform faults c. ) Extension and creation of new ocean crust d. Upwelling of magma from the core-mantle boundary

A

The graph describes the relationship between two characteristics of the ocean crust. What are the labels on the x- and y- axes most likely to be? (pic is a positive graph) a. x-axis: age ; y-axis: thickness b. x-axis: temperature; y-axis: age c. x-axis: distance from ridge; y-axis: iron content d. x-axis: depth; y-axis: heat flow

A

The topography of mid-ocean ridges can be mapped using satellites. While examining these images, a geologist notices that one ridge is narrow with steep slopes while another is broad with gentle slopes. What do geologists think causes these differences in topography? a. Difference in spreading rate b. Difference in lava temperature c. Difference in sediment thickness d. Difference in mantle composition

A

We can tell that many layers of rock on Earth have been deformed because: a. They form in horizontal layers but are now folded b. We can see rocks being deformed on other planets c. We can watch them being deformed as continents collide d. Earth is smaller now than when it was formed, so the rocks must be deformed

A

What features of rock strata would be most useful for a geologist to analyze in order to correlate rock layers in two different locations? a. Fossils b. Inclusions c. Angular unconformities d. Cross-cutting relationships

A

What property of index fossils makes them so useful for subdividing geologic time? a. They are short-lived. b. They are radioactive. c. They are exceptionally old. d. They are present in both young and old layers of rock.

A

Which statement accurately describes the relationship between stress and strain? a. Stress causes strain. b. Strain causes stress. c. Stress and strain both refer to the force applied to a rock. d. Stress and strain both refer to the permanent deformation of a rock.

A

Which statement regarding the supercontinent cycle is most accurate? a. Rifting in one area is associated with collision in another. b. Earth as a whole goes through episodes of rifting followed by episodes of collision. c. At any given point in time, tectonic activity is concentrated in a small region on Earth's surface. d. Throughout geologic history, tectonic activity has been roughly evenly distributed across Earth's surface.

A

Why might it be difficult for a geologist to measure the hinge of the fold shown in the picture? SEE PIC OF ROCK a. It plunges back into the rock formation, so it is not exposed. b. The fold is on its side, which means that it does not have a hinge. c. It is difficult to tell which layer is the youngest and which layer is the oldest. d. It has two hinges, one above the axial plane and one below, and each hinge is oriented differently.

A

Earthquakes

All tectonic plate boundaries can cause earthquakes (see maps on the previous assignment) Hot spots can cause earthquakes Fracking- the water being pumped in can cause earthquakes

Magma formation: water

Adding water lowers melting temperature of rocks

Earthquakes occur: - At divergent boundaries - At convergent boundaries - At transform boundaries - All of the above

All of the above Earthquakes can even happen at intraplate locations!

Which type of coal is the cleanest burning? • Anthracite • Bituminous • Lignite

Anthracite- not as many particulates because it is most carbon in it • Higher coal grade, lower ash and water content • Burns hotter because more carbon and less "other stuff"

What happens when a convergent boundary forms

Any time you have subduction there is going to be a trench, in water, and some sort of volcanic activity

A geologist determines the chronological order in which layers of rock were deposited in a canyon. How is this different from determining the absolute age of the rocks? a. The order of rock layers was not examined. b. The exact age in years of each rock layer was not calculated. c. The fossils contained in successive rock layers were not compared. d. The rock layers could not be classified in terms of period on the geologic time scale.

B

A geologist identifies an angular unconformity in a rock formation. What is the unconformity evidence for: a. Deformation followed by intrusion b. Deformation followed by uplift, erosion, and deposition c. Two phases of deposition separated by a major gap in time d. Two phases of deformation separated by a major gap in time

B

A scientist is writing a grant proposal to study a portion of the hydrosphere. Which is she most likely to be interested in? a. Clouds b. Glaciers c. Plants d. Volcanoes

B

A student who is interested in studying how earthquake waves travel through rocks should get a degree in: a. Geochemistry b. Geophysics c. Hydrogeology d. Petrology

B

Climate forcing refers to: A the forces that act on climate B processes that disrupt Earth's heat balance, forcing the climate to change C a measured change in climate due to anthropogenic inputs

B

Continents grow over time primarily as a result of: a. ) Divergence of plates, which leads to igneous activity and creation of new crust b. Convergence of plates, which leads to igneous activity and accretion of landmasses c. Motion along transform faults, which brings together the continental rocks from two plates d. Upwelling of magma from the deep mantle, which leads to eruption of large volumes of magma

B

Heat flow from Earth's interior to its surface and atmosphere: a. Is negligible b. Is associated with plate tectonics c. Is roughly the same everywhere on Earth d. Varies randomly from place to place on Earth's surface

B

How are detachment faults and thrust faults similar? a. Both are high-angle faults that occur near the surface. b. Both are low-angle faults that occur at depth in the crust. c. Both are characteristic of extensional tectonic environments. d. Both are characteristic of compressional tectonic environments.

B

Most new ocean crust forms: a. At hotspots b. At mid-ocean ridges c. Along deep sea trenches d. At the edges of continents

B

Most rocks are made of: a. Fossils b. Minerals c. Native metals d. Soil, shell, and bone

B

One possible mechanism of tectonic plate motion is ridge push. Which statement best describes ridge push? a. Mantle plumes move upward below the ridge, pushing lithosphere to either side. b. Plates on either side of the ridge slide downslope away from the ridge under the force of gravity. c. Convecting asthenosphere below the ridge pushes along the lithosphere above. d. Lava pushes the plates to either side as it erupts along the ridge.

B

The ancient mountain belts that make up the core of North America primarily formed as a direct result of: a. Seafloor spreading b. Subduction and collision c. Comet and asteroid impacts d. Mantle upwelling at hotspots

B

The photograph shows small folds, or crenulations, in phyllite. These folds are an example of: SEE PIC OF ROCK (FLAT) a. Brittle deformation b. Plastic deformation c. Elastic deformation d. Metallic deformation

B

Transform faults are referred to as "conservative" plate boundaries because: a. One plate is destroyed while the other grows b. Lithosphere is neither created nor destroyed at the boundaries c. There is no relative motion between the plates along the boundary d. Seismic energy is transformed into other types of energy during earthquakes

B

Which best describes what geologists think regarding the origin of hotspots? a. All evidence suggests that hotspots originate at the core-mantle boundary b. Some geologists think that hotspots originate at the core-mantle boundary, but others think they originate much closer to the surface. c. Geologists have no idea where hotspots originate. d. There are no more than a dozen competing ideas as to where hotspots originate.

B

Which factor is a challenge to geologists in establishing the boundaries of the geologic time scale? a. Some radiometric dating techniques are becoming more precise. b. Most rocks do not contain minerals that can be dated using radiometric dating. c. The rates at which past geologic events have occurred has varied through Earth's history. d. The exponential decay of radioactive atoms means scientists are running out of time to obtain radiometric data.

B

Which option from the chart shows a non-renewable resource? see pic 100

B

Which pictures shows a low rainfall period of time? (pic <3)

B

Which shows the correct order, from oldest to youngest, of the relative ages of the formations shown? SEE PIC OF CARTOON LAYERS a. A, B, C, D b. D, B, C, A c. A, C, B, D d. D, C, B, A

B

Which would generally NOT be involved in determining the relative age of rock strata? a. Unconformities b. Radioactive decay c. Rule of superposition d. Cross-cutting relationships

B

Charcoal is made from partially combusted wood, and it generates more energy per pound than wood. What might be important to the manufacture of charcoal? - Wetting the wood, and then burning it at a very high temperature - Soaking wood in a mineral solution so that cells are replaced with minerals, e.g. SiO2 - Burning the wood in very low oxygen conditions - Burning the wood in the presence of oxygen

Burning the wood in low oxygen conditions

A geologist analyzes the amount of potassium-40 in a rock and determines that 25 percent of the original potassium-40 is still present. Assuming no potassium-40 has been lost to any process other than radioactive decay, what is the approximate absolute age of the rock? SEE PIC OF TABLE a. 750 million years b. 312 million years c. 2.5 billion years d. 5 billion years ?????????

C

A geologist examines a rock formation that consists of flat layers. Under a microscope, the rocks appear to consist of grains of sand cemented together. What type of rock is this? a. Fossil b. Igneous c. Sedimentary d. Metamorphic

C

A geologist is designing an animation to illustrate subduction. To make the animation as accurate as possible, the geologist should make sure that: a. The trench migrates toward the island arc over time b. The trench migrates parallel to the island arc over time c. The trench migrates away from the island arc over time d. The location of the trench does not change over time

C

A geologist trying to understand ancient continental rifts wants to study a present-day rift. Where is the best place to conduct the research? a. California b. Chile c. Kenya d. Antarctica

C

A scientist wants to conduct field work to learn more about subduction. Where is the best place for the scientist to study? SEE PIC a. Iceland b. Madagascar c. Chile d. Hawaii

C

An earthquake of magnitude 7 occurs along a major transform fault underwater, but the tsunami risk is assessed as very low. Why? a. The earthquake is not strong enough to cause a tsunami. b. The earthquake does not last long enough to cause a tsunami. c. The motion that occurs during the earthquake is primarily horizontal. d. The motion that occurs during the earthquake sucks the water down rather than pushing it up.

C

Because Earth's surface is curved, the mid-ocean ridges are segmented rather than continuous. The segments of each ridge are connected by: a. Island arcs b. Volcanic fissures c. Transform faults d. Deep sea trenches

C

Carbon-12 and carbon-14 are both found in living organisms. What is the difference between carbon-14 and carbon-12? a. Carbon-14 has a greater atomic number. b. Carbon-14 has two more protons in its nucleus. c. Carbon-14 has two more neutrons in its nucleus. d. Carbon-14 has two more electrons surrounding its nucleus.

C

CarboncanexistatC-12,C-13,orC-14. Which isotope is radioactive? A. C-12 B. C-13 C. C-14 D. They are all equally radioactive

C

Divergent plate boundaries are characterized by landforms that result from: a. Compression b. Destruction c. Extension d. Shear

C

Earth's four major surface components, or reservoirs, are known as: a. Atmosphere, crust, mantle, core b. Continents, oceans, clouds, forest c. Geosphere, hydrosphere, atmosphere, and biosphere d. Lithosphere, asthenosphere, magnetosphere, ferrosphere

C

Earth's tectonic plates are made of: a. The uppermost crust only b. The entire crust only c. The crust and uppermost mantle d. The crust and entire mantle

C

Geologists think that plate tectonics has been operating on Earth: a. For the past 4.6 billion years b. Only over the past 200 million years c. At least for the past 2.5 billion years ago d. Episodically, every 100-300 million years

C

How does the principle of uniformitarianism differ from earlier views of the geologic processes that have shaped Earth? a. It claims that the structures on Earth are gradually becoming more uniform in shape and composition. b. It proposes that only gradual, slowly occurring, natural processes can significantly affect the structures on Earth. c. It suggests that the processes currently shaping the Earth are the same processes that shaped Earth throughout its history. d. It asserts that the processes shaping Earth have slowed to a more gradual pace compared with earlier catastrophic events that occurred more frequently in Earth's past.

C

James Hutton is known as the "father of modern geology." On what did Hutton base his interpretations? a. Biblical scriptures b. Peer-reviewed journal articles c. Careful observations and reasoning d. Conversations with other philosophers

C

Mercury, Venus, and Mars are known as terrestrial planets because a. They orbit the Sun, like Earth b. They are 4.56 billion years old, like Earth c. They are made of rocky material, like Earth d. They formed from the solar nebula, like Earth

C

Running water, wind, waves, and glaciers are collectively known as: a. Crystal forms b. Metamorphism c. Agents of erosion d. Igneous processes

C

Strips of magnetized rock on the ocean floor are arranged in which pattern? a. Concentrically about the poles b. Concentrically about the continents c. Symmetrically about the mid-ocean ridges d. Symmetrically about the deep sea trenches

C

The Himalayas are the tallest mountain range on Earth. Many of the peaks are at an elevation greater than 7000 meters. A geologist writes a proposal for funding to drill a continuous core through the crust of the Himalayas. Assuming it is vertical, approximately how long would this core be? a. 8 kilometers b. 7000 meters c. 80 kilometers d. 700 kilometers

C

The absolute age of a rock is the: a. Length of time over which the rock formed b. Period of geologic time in which the rock formed c. Amount of time that has passed since the rock formed d. Age of the rock relative to older and younger rocks around it

C

The strike of a layer of tilted sedimentary rock is: a. The orientation of the layer when it was deposited b. The direction that water would flow down the layer c. The orientation of a horizontal line on the surface of the layer d. The direction of the line where the layer intersects Earth's surface

C

Volcanoes are rare at C-C convergent boundaries because: - Magma is not produced - Magma is mafic and rises quickly - Magma is felsic and rises slowly - There is very little water in the rocks

C

What is the first step in the formation of a new ocean basin? a. Flooding of low coastal areas b. Erosion of a continent to create a low area c. Stretching and thinning of the continental crust d. Deposition of clay and silt-rich sediments during a flood

C

Which best describes the general motion along a transform? a. Slow and continuous slipping at an even rate b. Continuous slipping that increases in rate over time c. Slow buildup of stress followed by sudden release as rocks break and move d. Regular pattern of stop-start motion that repeats on the order of several times per day

C

Which best describes the topography of the Moho? a. It is generally flat and featureless. b. It mimics the topography of Earth's surface. c. It mirrors the topography of Earth's surface d. It has an apparently random pattern of hills and valleys.

C

Which best summarizes Alfred Wegener's idea of continental drift? a. As new ocean crust forms along mid-ocean ridges, the continents drift apart. b. Over time, continents sink to form ocean floor as ocean floor rises to form new continents. c. All of the continents on Earth were once joined as a single continent, which has since split apart. d. All of the continents on Earth were once joined as a single continent, which has since been partially flooded to form separate landmasses.

C

Which statement about the relationship between plate tectonics and mountain building is true? a. Mountains are found only along active plate boundaries. b. Plate boundaries tend to form along ancient mountain belts. c. Different types of mountains form along different types of plate boundaries. d. Mountains that form along plate boundaries are all very similar to each other.

C

Atlantic Tsunami?

Canary Island Hot spot

The boundaries between various periods on the geologic time scale are based primarily on: a. Fault planes b. Radiometric dating c. Nonconformities and disconformities d. Emergence or extinction of organisms preserved in the fossil record

D

Layers of the Earth

Crust Lithosphere- crust and upper most part of the mantle Asthenosphere Mantle Outer core Inner core

"The present is the key to the past" best summarizes which principle in the history of geologic time? a. Plutonism b. Gradualism c. Catastrophism d. Uniformitarianism

D

A dip-slip fault is defined as a fault in which: a. Motion has tilted the block of rock sideways b. Motion has dropped the block of rock downward c. Motion has occurred generally parallel to the horizontal orientation of the fault plane d. Motion has occurred generally perpendicular to the horizontal orientation of the fault plane

D

A student is trying to figure out if a particular fracture is a joint or a fault. What question should she ask herself? a. How long is the fracture? b. How wide is the fracture? c. What type of rock is the fracture in? d. Is there evidence of motion along the fracture?

D

A student needs to locate a transform boundary on a map. Where is the student most likely to find one? a. Perpendicular to a hotspot track b. In the middle of a plate, along the edge of a continent c. In the middle of a plate, directly between a ridge and a trench d. Along a plate boundary, between a segment that is divergent and a segment that is convergent

D

Deformation and fold mountain building can occur along transform faults where: a. Motion along the fault is very slow b. Motion along the fault is relatively fast c. The fault curves, causing the rocks on either side to extend d. The fault curves, causing the rocks on either side of the fault to compress

D

Folds form primarily in which tectonic environment? a. Passive b. Extensional c. Gravitational d. Compressional

D

Most of the current oceanic crust is less than 200 million years old. How do geologists interpret this observation? a. Prior to 200 million years ago, there was no dense basaltic crust. b. Oceanic crust older than 200 million years has buoyed up to form continents. c. Prior to 200 million years ago, there were no oceans to weigh down the continents. d. Oceanic crust older than 200 million years has been destroyed at convergent boundaries.

D

The Josephine Ophiolite is Jurassic formation of gabbros, peridotites, sheeted dikes, and pillow lavas in coastal northern California and southern Oregon. This formation is interpreted as evidence for: a. Episodic mountain building b. Basaltic magmatism beneath the continental crust c. Strike-slip motion along an ancient transform fault d. Uplift of pieces of oceanic crust during subduction or collision

D

The half-life of a radioactive isotope in a fossil is defined as: a. Half of the absolute age of a fossil b. The ratio of the daughter isotope to the parent isotope in the fossil c. The number of times the isotope undergoes radioactive decay in the fossil d. The time it takes for half of the parent isotope to decay into a daughter isotope in the fossil

D

The photograph shows a sedimentary layer overlying metamorphic rocks. How is the boundary between the two formations best described? (Photo Source: Margaret W. Carruthers.) SEE PIC OF LOTS OF ROCKS a. A fault plane b. A bedding plane c. A disconformity d. A nonconformity

D

The principle of catastrophism is NOT supported by which observation? a. Sudden floods can carve wide, deep valleys in a very short time. b. A volcanic eruption can form a mountain over the course of a few days. c. A rock from space can crash into Earth's surface, forming a giant hole. d. A continent can drift from one side of the globe to the other over millions of years.

D

The principle of isostasy explains: a. How continental crust and oceanic crust form b. How the volume of water in the ocean basins is increasing in volume c. Why oceanic crust has a different composition than continental crust d. Why continents have high elevation and ocean basins have low elevation

D

The site of a continental collision is generally characterized by: a. A single broad, smooth, planar suture of rock from one continent to rock of another continent b. A zone of deformation that is only recognizable by examining thin sections of the rock under a microscope c. A fairly narrow zone of folds whose axes are all oriented roughly 90 degrees to the direction of relative plate motion d. A wide, complex zone of faulted and folded rock formations with evidence for compression, extension, and translation

D

This diagram illustrates: A. Mafic magma is hot enough to melt felsic rocks B. Felsic magma is hot enough to melt mafic rocks C. Felsic magma could have solid mafic minerals in it D. A and C are both true E. B and C are both true (pic $)

D

When using radiometric dating to determine the absolute age of a rock, which quantities does a geologist compare in a sample? a. The half-lives of various isotopes b. The numbers of radioactive isotopes c. The concentrations of different minerals d. The amounts of daughter and parent isotopes

D

Whether a certain region of rock is considered to be part of the lithosphere or part of the asthenosphere is based on: a. The depth of the rocks b. The mineralogy of the rocks c. The composition of the rocks d. The physical properties of the rocks

D

Which best describes an ocean trench? a. A wide, flat basin with steep sides b. A straight, narrow valley along the center of a mid-ocean ridge c. A deep fracture perpendicular to and intersecting a mid-ocean ridge d. A deep, curved depression near the margin of a continent or chain of volcanic islands

D

Which best summarizes the hypothesis of seafloor spreading? a. Lava erupts from hotspots and spreads over the ocean floor. b. The seafloor gradually spreads in size as a result of erosion of the continental shelves. c. Sediments from continents are carried to the ocean in rivers and spread out on the ocean floor. d. Lava erupts from the mid-ocean ridge and is carried away as the floor of the ocean spreads apart.

D

Which do geologists primarily use to determine the absolute ages of boundaries on the geologic time scale? a. Correlation methods b. Cross-cutting methods c. Law of superposition d. Radiometric dating

D

Which is a main reason why Wegener's ideas about continental motion were not accepted by most geologists during his lifetime? a. The idea that ocean floor could dive back into Earth's interior seemed absurd. b. The idea did not explain the formation or location of hotspots on Earth's surface. c. The idea that Earth was more than 6000 years old was inconsistent with all other geological evidence. d. The idea that continents could move went against preconceived notions that the major features on Earth's crust are fixed in place.

D

Which part of the fold shown in the picture is the hinge? SEE PIC OF ROCK a. A b. B c. C d. D

D

Which type of strain is associated with confining pressure? a. Rotation b. Thinning c. Change in shape d. Decrease in volume

D

Where is an obvious unconformity? (SEE PIC) A. Between A and D B. Between C and D C. Between "E/B" and C D. Between E and B*****

D?

If inputs to the atmosphere increase, what happens to the size of the atmosphere reservoir?

Decreases

What order of events occurred to create Siccar Point Unconformity

Deposition of sediments ~425 million years ago Compaction/cementation of ~425 million years old sediment to make rocks Deformation/tilting of sedimentary rocks (w/ ~425 MYO sediments) Exposure and erosion of sedimentary rocks (w/ ~425 MYO sediments) at the surface ~345 million years ago Deposition of sediments ~345 million years ago Compaction/cementation of ~345 million years old sediment to make rocks Deformation/tilting of sedimentary rocks (w/ ~345 and 425 MYO sediments) Exposure and erosion of sedimentary rocks (w/ ~345 and 425 MYO sediments)

Normal faulting (and examples)

Divergence - Mid-Ocean Ridge- a submarine mountain chain buoyed by underlying mantle heat - Continental Rift- a divergent plat boundary is the site of the breakup of a continent and new ocean formation - Passive Margin- a continental shelf that forms when thinned margins of a continent slowly subside, settle, flood and become covered by marine sediments following continental rifting; these margins come to lie far from any plate boundary because the ocean that opened when the margins first formed widens

Sedimentary Rocks and Relative Dating

Each sedimentary layer in an undisturbed sequence is younger than the one beneath it and older than the one above it

Aquifers

Earth material capable of supplying groundwater at a useful rate from a well, a lot of times you are looking at a rock that is fully saturated- based on humans ability to use this stuff, able to supply water at a useful rate and ability to get it out. - Porosity = pore space that can be filled with water Permeability = ability to transmit water

The oldest rock and oldest mineral

The oldest rock: metamorphic 3.96 billion years old Oldest mineral (in a sedimentary rock): 4.404 billion year old zircon

Beneficiation: Smelting

Emissions include sulfur dioxide, lead, particulates...

Erosion Features: U and V- what are they made from?

Erosion feature: U-shapes (glacial) valley Erosion feature: V-shaped (river) valley

Principle of Cross cutting relationships

Fault must be younger than all the rock layers (the fault occurred after rock layers

Complicated question

Feedback loops: modification of a process by changes resulting from the process itself- positive feedback versus negative feedback loop

Measuring the Size of an Earthquake

For local magnitude (Richter): measure S-wave amplitude

Which energy options below are non-renewable?

Fossil Fuels

Earthquake Triangulation

Knowing the difference in arrival time for P- and S- waves, we can determine the distance of a seismic stations from the focus

Drainage Ditches- Why did we fill the ditch with gravel?

Gravel has high permeability

Groundwater discharge is a measure of water exiting the aquifer, and is measured in the same way as river discharge. This means: - Groundwater discharge = groundwater velocity - Groundwater discharge = groundwater volume - Groundwater discharge = groundwater volume per unit time

Groundwater discharge = groundwater volume per unit time

Groundwater recharge Groundwater discharge

Groundwater recharge: volume entering aquifer (per unit time) Groundwater discharge: volume exiting aquifer (per unit time)

How do we mine coal?

Horses could lift 220 lbs 100 ft per 1 minute

Rock types and mineral deposits (don't need to have it memorized)

Igneous rocks - Diamonds and chromite (mafic) - Aluminum, beryls, tantalum (felsic) - Iron, copper, silver, mercury, gold (mafic hydrothermal fluids) - Zinc, lead, tin, tungsten, uranium (felsic hydrothermal fluids) Metamorphic - Lead and silver, asbestos, garnets, kyanite Sedimentary - Halite, phosphate (evaporites) - Paleoplacer deposits (sediments concentrated metals of interest) - Fossil fuels (non-mineral resources)

Oil Traps

Impermeable cap rock and underlying structure needed to concentrate oil

Weathering after orogeny events

Isostasy will cause uplift concurrent with erosion

Physical and chemical weathering

More exposed surface area, more physical and chemical weathering occurs Changes to the landscapes: Weathering dominates in some areas, deposition in others - The corners of the rock in the picture on the left are going to go first and going to make it round- the longer something has been weathered, the more round it typically is - A lot of times you can tell how far a rock is from their home based on how small they are

Principle of Original Horizontality

Most sediment in deposited in horizontal layers If layers are not horizontal, something has happened (deformation)

Greenhouse gases

Prevent heat from escaping Earth's atmosphere

Beneficiation: Flotation

Schematic of one method of flotation. Pine oil is a reagent that can be used for copper beneficiation. (think of a stick blender)

The Geologic Time Scale

Smith's work led to the development of the geologic time scale - Determined before absolute dates were known - Based on fossil record/major changed in fossil record Absolute dates discovered later....

California's- San Andrea's Fault

Some areas of the fault are slowly creeping, while other areas are locked (building up stress)

Radioactive Decay

Spontaneous breakdown of an atomic nucleus resulting in the release of energy and matter- it happens all by itself, nothing makes it happen, just by its existing it will be unstable--- radioactive elements have the same attributes as geologic clocks because they are good geologic clocks ○ Unstable (heavy) element breaks and emits: § Energy (gamma waves) and/or § Particles (electrons, protons, or neutrons) □ If number of protons changes, a new element forms! □ If number of neutrons changes, a new isotope forms Release of waves and particles generates heat

Where does shale gas fit in?

Step 7

Where do tar sands fit in?

Step 9

If a material is impermeable, this means: - It is an impenetrable barrier against water - Water cannot be easily transmitted through it

Water cannot easily be transmitted through it

Energy released: Elastic Rebound Theory

Stress builds until it exceeds rock strength, then movement occurs Movement creates energy that radiates in all directions as of seismic waves (see pic 6)

Tectonic setting (see pics 1 and 2)

Subduction zone 50km deep Rate: 76mm/year Normal fault

Geologic Time

The Earth is old, and has changed a lot in the past We can hypothesize what Earth's history looked like by making observations of landscapes - Tectonic features: mountains, rifts, ridges, etc - Erosional/depositional features: valleys, rivers, etc - Rock type: • Igneous: Magma cooling (tectonics generates magma) • Metamorphic: Heat and pressure (tectonics- mountain building, contact with magma or hot fluids, and/or lots of sediment deposition) • Sedimentary: Compaction and cementation of sediments (occurs in low-elevation areas where lots of sediment deposits)

Put the statements in correct chronological order of how petroleum forms:

The story of oil and gas begins with planktonic organisms living in the ocean (or in lakes), Zooplankton eat phytoplankton (algae) that used the Sun's energy to produce organic matter and energy through photosynthesis, As the planktonic organisms die, their remains begin to settle to the sea floor under anoxic conditions (without oxygen), Over time, layer upon layer of marine sediments accumulate, containing the remains of planktonic organisms, Thick sequences of sediments are deposited and the planktonic organisms buried in them are heated and compressed until the organic matter begins to change into kerogen, a solid, waxy, organic material, With the high temperatures and pressures of greater depth of burial, the kerogen begins to change into hydrocarbons, With even more heat and pressure, the hydrocarbons are broken down into petroleum (oil) and natural gas, The petroleum and natural gas migrate into porous and permeable sedimentary rocks such as sandstone, which serves as a petroleum reservoir rock, Oil floats on water, and gas is even lighter than oil, so petroleum and natural gas move upward within the reservoir rock, until they are stopped by an impermeable sedimentary layer such as shale, which forms a trap, More are more petroleum and natural gas accumulate, and become concentrated in the trap, forming an oil field, Wells are drilled into the oil field to extract the petroleum, which is called crude oil, The crude oil is transported to a refinery, where it is separated by distillation and other processes into fuels such as gasoline, butane, kerosene, liquid petroleum gas, jet fuel, diesel fuel, fuel oil, and chemicals used to manufacture plastics

If a material is porous, this means: - There are spaces in the rock that air or water can occupy - Water can easily be transmitted through the rock

There are spaces in the rock that air or water can occupy

Distribution of Earth's Water

Total global water - Oceans 96.5% - Saline ground-water 0.93% - Saline lakes 0.07% - Freshwater 2.5% Freshwater - Surface water and other freshwater 1.3% - Groundwater 30.1% - Glaciers and ice caps 68.6% Surface water and other freshwater - Atmospheric water 0.22% - Biological water 0.22% - Rivers 0..46% - Swamps and marshes 2.53% - Soil moisture 3.52% - Ice and snow 73.1%

Unconfined aquifer:

Unconfined: upper surface (water table) open to the atmosphere

Uniformitarianism vs. Catastrophism

Uniformitarianism: familiar processes, but hard-to-imagine lengths of time Catastrophism: Periods of catastrophic change on Earth punctuate otherwise stable conditions - Assumes geologic processes humans have never witnessed

Ocean Submergence

You cannot have submergence with two oceanic crusts because think of buoyancy (think of two kayaks on the water running into each other)

Newcomen's steam engine

You gotta burn coal to get coal

USGS Water Usage Data: North Carolina (2010)

a. Average use: ~154 gallons per day per capita (per person) b. Does not include industrial usage (cooling thermoelectric power plants, irrigation) Highest use: high population + thermoelectric power plant locations

Where does your water come from?

a. ~95% from surface water sources 1. Closer to 71% excluding industrial water usage b. Cane Creek Reservoir 1. 3 bil. Gal c. University Lake 1. 430 mil gal. d. Quarry Reservoir 1. 200 mil gal 1. Expansion project: increase to 2.2 bil gallons 10.5 mil gallons per day during drought

Viscosity of magma

based on composition - Felsic § High viscosity: magma flows with difficulty § Pyroclasts (solids) move quickly, propelled by high gas content § Intermediate/felsic magma - Mafic § Low viscosity: flows easily § Mafic magma

Unconventional oil: Where does oil shale fit?

between steps 5 and 6

Convergent

coming together- there is a subduction of one of the plates and it is being destroyed as it goes down-- the subduction pushes the magma up creating either an island volcano (if with water) or a volcano on land

Oceanic-continental convergent boundary

compression

Strike-slip faults

depends on if you were straddling the fault and decide which side is coming towards you- if right it is right lateral and vice-versa - Oceanic Fracture zones - Pull-apart basins - Linear features

Tar sands

form when oil moving upward within a reservoir of porous, permeable sand is not stopped by an impermeable sedimentary later. Oil begins to escape from the sand at the surface, and is biodegraded by oil-eating bacteria, causing the oil to become highly viscous asphalt or tar called bitumen. Tar sands can be mined and processed with hot water to separate bitumen from sand.

Conventional oil & gas

form within oil window, then travel from source rock to reservoir rock

Shale gas

forms in organic-rich black shales were extremely deep burial and extremely high temperatures have broken petroleum down into natural gas (methane). Shales have low permeability, so to extract the methane gas, it is necessary to create artificial fractures. Wells are drilled to thousands of feet deep, and then drilled horizontally along the shale bed. High pressure fluids and sand and injected to hydraulically fracture the shale, releasing the trapped gas (fracking)

Principle of Faunal Succession-

fossils succeed each other in a reliable order that can be identified over wise horizontal distances

Opening picture in lecture 9

granite on the left, normal of NC and limestone on the right, normal of TX - Limestone is being chemical changed through dissolving it- why limestone forms caves - Granite is more physical weathering, but also some chemical weathering- you can tell because you can see crystals, some of the minerals go away and some stay around for a long time

Zones of subsurface water

groundwater is only in the saturated zone - Unsaturated zone: water and air both occupy pore spaces - Saturated zone: water fills all pore spaces

Wilson Cycle

how we explain why we have super continents on the earth and then breaking apart- the heat from the core is going to be hotter underneath the continental crust instead of the think crust making the mantle very hot and it expands (lava lamp, heating up the liquid at the bottom making it rise because it is more dense) a cycle of tectonic activity that commences with rifting and the development of an ocean, followed by subduction and the formation of volcanic arcs and finally continent-continent collision

Climate Forcing

imposed, natural or anthropogenic perturbation of Earth's energy balance with space § CO2 has the most ability to change the temperature and there is an abundant amount of it § Reflective aerosols has the most ability to reduce the temperature - Radiative forcing = incoming energy - outgoing energy

Oil shale

is a sedimentary rock containing kerogen that has not been heated enough within the Earth to change the kerogen into hydrocarbons. Oil shale can be mined, but it must be subjected to a high temperature before petroleum-like liquids can be separated from the rock "the rock that burns" Heat in the absence of oxygen until kerogen decomposes into condensable shale oil vapors and combustible oil shale gas

Reservoir rock

porous layer that oil can travel through - Typically sedimentary

Discharge Over Time

it's a flood if the water is going to leave the river banks (green part on pic)

Transform Boundaries

just because there are three transform boundaries does not mean we have that many plates- there can be many transform boundaries

Source rock

kerogen- containing layer - Typically shale - Impermeable sedimentary rock: low-energy environments

Shield volcano

maple syrup on a pancake in the fridge versus heated- when you have slow magma it makes this shield shape

How could we make low-grade coal into high grade coal?

pressure, heat and low oxygen setting!

Ore

metal-bearing rock that can be mined at a profit Ores need to be located (Exploration), obtained (Extraction), and then concentrated (Beneficiation/Smelting/Refining). After mining is completed, surface and underground impacts should be remediated and the land reclaimed. Mines need to be safely closed. - Brainstorm (from below, our factors) § Market Value = Rare vs. Abundant (Demand) § Ease of extraction § Processing cost § Transportation cost § Definition of ore can vary base on: § Technology for extraction/refining § Economics/politics - Concentration factor: ration of metal to its necessary concentration for profitable mining - Brainstorm: what matters to profitability? § Concentration § Depth to ore § Environmental impact § Transportation and or water needs § Regulations § Political boundaries § Human health Etc.

"Surface" water

moves towards base level - The lowest level to which a river can erode: base level (aka sea level) - High above base level: much erosion - Closer to base level: less erosion - Sea level is ultimate base level

What do the two features shown in the previous slide likely have in common? (spewing water and oil)

pressure/amount of the substances in both provides them with the ability to spew upward like that - Under pressure: impermeable layer on top? - Liquid underground: found in aquifer material

Placer deposits

panning through sediment for gold - Pieces of gold are washed downstream from the main deposit - Density of gold; 19.2 § Gold weighs 19.2x as much as an equal volume of water Because gold is heavier than other rocks, they do not wash away easily

How to make coal

peat is compressed and lithified

Differential Erosion

some rocks and minerals are more resistant to erosion

The carbon cycle and climate change

the amount of CO2 in the atmosphere determines the temperature of the Earth - CO2 is a greenhouse gas - Greenhouse gases warm the atmosphere - CO2 concentrations are higher than they've been in 3.6 million years - The amount of CO2 in the atmosphere is due to burning fossil fuels Earth's temperature is not yet in equilibrium with current CO2 concentrations (when CO2 was this high in the Pliocene, average temperature in the Arctic was 60 degrees Fahrenheit)

Isostasy

the balance reached by Earth's crust and the lithospheric mantle as they float upon the denser, more pliable asthenosphere. According to this principle, the elevation of the crust depends upon its thickness and the density contrast with the asthenosphere.

1- How are groundwater and surface water related in A? 2- Is that relationship between groundwater and surface water different in B? (pic <3)

the lake also feeds ground water ...ground water is only in the saturated zone and you can see the interaction with the surface water in picture A but not picture B- looking at the different zones

Reverse faulting

the man hanging off the fault line, where is his head and where are his feet-- a reverse fault is created by compression - Foot wall- the bigger at the base-- moves down in a reverse fault - Hanging wall- the bigger at the top-- moves up in a reverse fault

peat

the more oxygen there is, the more decomposition there will be. The less oxygen there is, the less likely the bacteria is to break down and decompose anything (think of the sulfur smell in the lake as you step in it)

Divergent

the plates are being generated in the divergent setting

Refraction of seismic waves-

the speed of the wave ends up changing when it hits things of different density - Seismic waves bend when they encounter a new density - This created p-waves "shadow zones" - S-waves shadow zone: s-wave unable to travel through liquid outer core- this is also how we know the outer core is made of liquid

Paleomagnetism

the study and measurement of Earth's magnetic field in the geologic past, as preserved in minerals and rocks

Beneficiation: Crushing/Milling

there are many different methods of beneficiation - Increases surface area for reactions - Milling: the crushed ore is placed into a rotating drum with steel rods or balls to powder it - Water added to the powder to create a rock slurry

Crustal thickening

these rocks are really far down in the Earth and have the heat available to make it wavy like this and make it really thick when they come together (playdo)

Mercury

toxic heavy metal • "uncontrolled" mercury emissions- up to 170 lbs/year • 1/70th a teaspoon in a 25-acre lake makes fish unsafe to eat

Fracture zones

transform boundary scars- many along our mid-ocean ridges

Cap/seal rock

traps oil and prevents it from reaching surface

The map that changed the world-

used fossil evidence to compare ages of across large distances

Discharge

volume of water per time - For stream discharge, calculate cross section (depth X width) and multiply by water velocity - Each square is 1m x 1m; if velocity = 1.1m/sec, calculate discharge for this stream

Land Subsidence

water is difficult to compress into a small space than it already takes up

What is faulting?

when tectonic plates move, the lithosphere fractures and is displaced

Subduction zones

with convergent plate boundaries, is land actually being lost or is it being redistributed? Both of these things happen

Getting energy from...to electricity

§ Chem --> Grav --> Kinetic --> Thermal, Sound - Wind-- Kinetic ---> Electric - Solar - Fossil Fuels--- Chemical --> Thermal ---> (water) --> Kinetic - Nuclear--- Chemical --> Thermal ---> (water) --> Kinetic - Geothermal - Least conversions? - Best options? - Wind § Kinetic -> mechanical -> electric - Fossil fuels § Chemical -> thermal -> mechanical -> electric - Nuclear § Chemical -> thermal -> mechanical -> electric - Geothermal § Thermal -> mechanical -> electric -> mechanical -> electric - Efficiency of conversions are not equal! Storage is not part of the equation!

Energy in the past versus today

§ Wood § Geothermal energy: hot springs § Whale oil § Animals (horse power, etc.) § Water Wind

Horsepower

• Horses can lift 330 lbs 100 ft per minute • 10 horsepower steam engines can do lifting of 10 horses!

Energy for heating

• Manure • Wood • Peat • Charcoal • Coal 4,000-100,000 years for one meter of peat to accumulate

Coal

• Plants decaying in low- O2 conditions • Greater depth of burial - Carbon increases, - H2O and CO2 decrease • Approx.formula: - C135H96O9NS - ... with some S, Si, Na, Ca, Al, Ni, Cu, Zn, As, Pb, Hg....

Extraction: Surface Mining

• Thelargestminesare usually surface mines - Can produce up to 150,000 tons of ore daily - 2-3 tons of waste rock per ton ore (up to 450,000 tons of waste rock daily) - Most of ore is also "waste" • Heavymachineryand blasting procedures used

Extraction: Waste Rock

• Waste Rock: Broken rock that doesn't contain the ore in high enough concentrations - Overburdenorsurroundingrock - Usuallydepositedclosetomine • Piles can cover hundreds to thousands of acres, 100+ feet high - 40% of all solid waste generated in the US is from mining

Impacts of Mt. St. Helen's eruption

• Wildlifeimpacts - 5,000 deer, 200 black bears....etc • 1200 ̊Fsteamandashsterilizedsoilanddeposited pumice/ash up to 60 feet deep • SpiritLake - Landslide of pyroclasts raised temperature to 100 ̊F - Heat and ash killed all life - Debris (trees, earth, etc) was pushed into lake

Which of the following are minerals? Ice Coal Asbestos Gold Jasper (chert)

□ Ice: Yes a mineral □ Coal: No- it's organize and has no crystal structure □ Asbestos- (crystallization involves making really fine needles that can be airborne and hurt you if it's in your house)- Yes a mineral □ Gold- Yes a mineral (difficult to see crystal structure) Jasper (chert)- (flint) No...no crystal structure?

Earthquake Probability

○ Earthquake in a 50 year period (1967-2017) in northern Sumatra ○ Calculate frequency of earthquakes at each magnitude per year (fill out table) ○ What percent probability is there that a magnitude 7.0 or greater earthquake will occur in a given year?

Magma formation (see pic $)

○ Line slopes because higher pressure acts to keep rocks solid (pressure up w/ depth) ○ How could a rock starting at point A to melt? ----At point C?

What is magma?

○ Molten rock ○ Mineral crystals- think about the melting of a penny- ○ Dissolved gas- think of the seltzer water not having bubbles when the bottle is closed and under pressure but turning back into a gas when you open the cap ○ Composition of magma: § Based on source rock § Related to tectonic setting ○ Composition of magma determines: § Eruption style § Volcano shape

Tsunamis

○ Move across ocean at 500-950 km/hr; slow at shallower depths and pile up at 30 meters high ○ Commonly preceded by rapid retreat of coastal waters ○ As you get closer to the shore- the waves are going to get denser and higher

Earthquake Magnitude

○ Richter Scale: Good for earthquake magnitudes >3 and >7 ○ Moment magnitude now used: § Seismic moment □ Area that ruptured alone fault plane □ Amount of movement or fault slip □ Rigidity of rocks § 1.0 increase in magnitude = 10 times the wave amplitude § 1.0 increase in magnitude = 30 times the energy release § 90% of energy release every year is from EQ's > M 7.0

Building up to an earthquake

○ Stress: force per unit area ○ Strain: responses to stress (deformation/breaking) ----Rubber band analogy for the pictures- we push on it and make stress and then it snaps (see pic 3)

Where are tsunamis likely to occur?

○ Under water faults with vertical movement ○ Oceanic volcanoes with explosive eruptions or associated landslides

Where does surface water come from?

○ Watershed: all water that falls within a watershed (shaded area) drains to the same place Boundary between basins is a drainage divide- think of dropping water on your knuckle and it going one way or another

The orientation of a hotspot track can be used to infer: a. The direction of motion of a tectonic plate b. Where strong earthquakes are likely to occur c. Where a new plate boundary is likely to form in the near future d. The approximate depth inside the Earth where the hotspot magma originates

A

The table describes four samples of Earth materials. Which sample is a mineral? Sample Description A Solid crystals; chemical formula: CaCO3 B Mixture of quartz, mica, and feldspar crystals C Solid bone D Liquid; chemical formula: Au a. A b. B c. C d. D

A

When scientists refer to "geologic time," they are generally referring to: a. Processes that occur over millions of years b. Events that occur periodically (every 10 to 100 years) c. Events that occur instantaneously (on the order of nanoseconds) d. Processes that occurred in the distant past and are no longer active on Earth

A

If layer C is 15 million years old, and layer A is 5 million years old, how old is layer D? A. Older than 15 million years B. Between 5 and 15 million years C. Younger than 5 million years D. Cannot be determined with this information

B

If rifting continues in a continental rift valley, which is most likely to form next? a. A hotspot track b. A new ocean basin c. A subduction zone d. A high, wide mountain belt

B

Modern geological sciences began in the: a. Early seventeenth century b. Late eighteenth century c. Late nineteenth century d. Mid twentieth century

B

Put these people in chronological order from young to old using the information given. Dr. Plenge is twice the age of Dylan, who is 3 years younger than Rebecca. Jim has been three times longer than Rebecca has. Dylan, Rebecca, Jim, Dr. Plenge Dylan, Rebecca, Dr. Plenge, Jim Rebecca, Dylan, Jim, Dr. Plenge Dylan, Dr. Plenge, Rebecca, Jim

B

The diagram shows a chain of hotspot volcanoes in an ocean. The arrow shows the direction of motion of the tectonic plate. What can a geologist assume about the ages of the volcanic rocks that form the islands? (SEE PIC) a. All of the rocks are about the same age. b. The rocks increase in age from Volcano A to Volcano D. c. The rocks decrease in age from Volcano A to Volcano D. d. There is a random distribution of rocks of various ages on the islands.

B

Which best summarizes the process of subduction? a. Old, thick continental lithosphere slowly sinks under its own weight. b. Old, dense oceanic lithosphere dives beneath younger or lighter lithosphere. c. Extensive volcanism empties a magma chamber and causes the crust to collapse in on itself. d. Two tectonic plates move suddenly past each other when the rocks break and friction between them is overcome.

B

Students were asked to give examples or descriptions that demonstrate their understanding of absolute time versus relative time. Their responses are shown in the table. Whose response is best? Example Relative Time Absolute Time Mary The dinosaurs lived during the Paleozoic Era. The dinosaurs lived during the Mesozoic Era. Shen The dinosaurs lived during the Mesozoic Era. The dinosaurs lived during the Triassic Period of the Mesozoic Era Abe The dinosaurs lived during the Mesozoic Era. The dinosaurs lived 245 million years ago. Arthur The dinosaurs lived 245 million years ago. The dinosaurs lived 245.3 million years old a. Mary b. Shen c. Abe d. Arthur

C

The principal division of Earth's interior into asthenosphere and lithosphere is based on variations in: a. Age b. Depth c. Physical properties d. Chemical composition

C

What is the difference between the lithosphere and the asthenosphere? a. The lithosphere is solid, while the asthenosphere is liquid. b. The lithosphere is rich in silicon, while the asthenosphere is rich in iron. c. The lithosphere is hard and rigid, while the asthenosphere is soft and weak. d. The lithosphere makes up the continents, while the asthenosphere underlies the oceans.

C

Which is the best example of a convergent plate boundary? a. The Connecticut Valley, where rifting began but failed b. Iceland, where a hotspot and a mid-ocean ridge are located in the same place c. The Himalayas, where the Indo-Australian Plate is colliding with the Eurasian Plate d. The Alpine Fault in New Zealand, where the Pacific Plate slides past the Indo-Australian Plate

C

Which option below lists the layers in order from oldest to youngest (furthest back in time to most recent)? (SEE PIC) Note: "B" is representing an igneous intrusion: Magma that begins moving toward Earth's surface but solidifies before each A. B, E, C, D, A B. E, B, C, D, A C. E, C, B, D, A D. B, C, E, D, A ????????????

C

An igneous rock can become a metamorphic rock through the processes of: a. Erosion and deposition b. Melting and solidification c. Cooling and crystallization d. Heating and recrystallization

D

How did Wegener's hypothesis of continental drift differ from the current theory of plate tectonics? a. Wegener's hypothesis was supported with evidence from fossils and rock formations. b. According to Wegener's hypothesis, South America and Africa were father apart in the past. c. According to Wegener's hypothesis, the driving force for plate tectonics was mantle convection. d. Wegener's hypothesis was based on the assumption that the continents were much younger than the ocean basins.

D

On Earth, hotspot volcanoes tend not to grow very large because: a. The lava they produce is very dense b. Hotspots do not produce much magma c. The hotspot moves steadily beneath the lithosphere d. The lithosphere moves while the hotspot stays in one place

D

Planets are thought to have formed in which way? a. Small stars cooled after exhausting the fuel in their cores. b. Particles of dust came together and settled around a central core. c. Star-sized bodies broke apart into smaller pieces after colliding with each other. d. Small bodies called planetesimals came together to form larger bodies, which then came together to form planets.

D

Plate tectonics is a scientific theory. This means that it is: a. A plausible idea that has not been fully tested yet b. The respected opinion of a single scientist or group of scientists c. An equation that can be applied in numerous situations throughout the universe d. An explanation that is supported by a wide variety of strong evidence and is generally accepted by the scientific community

D

The presence of a weathered crust on a rock on Mars would be evidence for: a. Extreme heat b. Burial to extreme depth c. Bombardment by comets d. Interaction with water, ice, or atmospheric gases

D

The theory of plate tectonics explains: a. Why Earth's magnetic field changes over time b. How Earth and other objects in the Solar System formed c. Why the planet's gravitational pull varies slightly from place to place on Earth d. The origin of mountains and ocean basins and the shapes of the continents on Earth

D

To serve as a geologic clock, a process must: - A. Have been operating, uninterrupted, since the Earth began - Be uniform (or at least subject to averaging) - Be capable of being measured - All of these things must be true

D

When do scientists think that Earth formed? a. About 13.8 billion years ago, during the Big Bang b. About 18 billion years ago, or 4.5 billion years before the Big Bang c. About 4.2 billion years ago, through the collision of a two other planets d. About 4.56 billion years ago, through the collapse of a disk of dust and gas

D

Which best defines the rock cycle? a. The motion of boulders down steep inclines b. The motion of the ocean crust from ridges to trenches c. The cyclical pattern of continent formation and breakup d. The continuous process of transformation of rocks from one type into another

D

Which is a practical and valid reason why it is important for people to understand geologic time? a. Understanding geologic time allows us to prevent natural catastrophic events. b. Understanding geologic time allows us to better control geological processes. c. Understanding geologic time allows us to justify human activities that cause changes to Earth's surface and atmosphere. d. Understanding geologic time allows us to differentiate between natural processes and those that result from human activity.

D

Unconformities

• A surface that represents a break in the rock record, caused by erosion or nondeposition • A gap in time in the rock record a sedimentary rock layer is missing either because it eroded or we didn't have (something) in the first place- we have a gap in time - If you have metamorphic rock and then sedimentary rock sitting on top of it- there is probably an unconformity

How to determine absolute age?

• James Ussher (1581-1656): - life spans of people in Bible and other ancient documents. - Assumes: people have always been on Earth • 6000 years old • Edmund Halley (1656-1742): - rate at which salt added to oceans. - Assumes: Salts are added to oceans but never removed • 90-100 million years • Charles Darwin (1809-1882): - Weathering, eroding, and depositing sedimentary rock. - Assumes: correct and uniform rates for those processes • Suggested one feature in England (Weald dome) took 300 million years to erode • Lord Kelvin (1824-1907): - Cooling rate of Sun and Earth. - Assumes: Heat is being lost but not added (did not know about radioactivity & nuclear energy • 10 million to less than 1 billion years

A geologic clock

○ A process that: § Is operating uninterruptedly throughout time § Happened at a relatively uniform rate § Can be measured Then, try to determined how long the Earth has existed based on the results of that process

Isotopes of Carbon

○ Atomic number of Carbon is 6 § It has 6 protons ○ Weight of Carbon is 12, 13, or 14 § Weight is determined by protons and neutrons ○ Carbon can exist as: § Carbon-12: 6 protons and 6 neutrons § Carbon-13: 6 protons and 7 neutrons Carbon-14: 6 protons and 8 neutrons--- radioactive!!!- heavy enough

Radioactive Isotopes: radioactive decay

○ Before decay, unstable parents atoms- we are assuming that we have all "un-popped" atoms- popcorn analogy ○ Half-life is defined as the amount of time it takes for 1/2 of parent atoms to decay- however long it takes for half the atoms to be turned into the daughters (see table in notes)

Looking Glass Rock

○ Igneous pluton- pluton means something that forms deep inside the earth and igneous has to do with magma- basically this is a failed volcano, the magma was not able to make it out of the crust, the magma moved up for so long in the thick crust that it cooled down before it could get to the surface § Magma generated by heat collision § Too deep or viscous to rise to the surface § Cools below the surface Later exposed through weathering/erosion

Weathering

○ Physical/mechanical weathering: breaks rocks into smaller pieces ○ Chemical weathering: chemically adds or removes elements from rock, transforms them ○ Biological weathering: can be chemical or physical ex: trees Erosion: movement of weathered material ex: wind

From (some people's) experience as rocks last week

○ Rivers meandering because it is not straight- in the pic on the pp it went down then up then down and then back up ○ River deposition of sediment--> goes back to mountains ○ Tectonic uplift ○ LOTS OF TIME required Stream rejuvenation

The evolution of landscapes by natural processes takes time

○ Siccar Point- all the sediments that laid down horizontally then turned vertically- there is a gap in the rock record and that takes a really long time § Rock formation 1. Igneous 2. Metamorphic 3. Sedimentary § Deformation/movement of rock § Erosion of rock § Repeat

Convergence Features: Thrust Fault and Deformation/Thickening of Crust at Depth

○ Thrust fault: low angle reverse fault, horizontal movement ○Deformation/thickening of crust at depth-- these rocks are really far down in the Earth and have the heat available to make it wavy like this and make it really thick when they come together (playdo)

Radioactive decay acts as a geologic clock

○ Zircon grain contain radioactive uranium ○ U decays to lead (Pb) at a specific rate § Half-life: length of time it takes for half of the U to decay § 1/2 life of U-238: 4.5 billion years Ratio of U to Pb tells us how long decay has been occurring

Evolution of the Appalachians

○ ~550 MYA: supercontinent Rodinia (superseded Pangea) breaking apart § Wilson Cycle- how we explain why we have super continents on the earth and then breaking apart- the heat from the core is going to be hotter underneath the continental crust instead of the think crust making the mantle very hot and it expands (lava lamp, heating up the liquid at the bottom making it rise because it is more dense) ○ ~470 MYA: plate motion changes, Taconic orogeny- movement onto the continental crust ○ ~375 MYA start of Acadian orogeny with Avalon micro-continent ○ ~330 MYA N. American, now apart of Laurasia, collides with Gondwana to form Pangea ○ At that point, the Appalachians are as high as the modern day Himalayas - The collision zones started rifting to form the Atlantic Ocean in the Jurassic (180 MYA)