Geology Final Exam
Why is the earth considered a system?
Multiple parts working together (interacting)
Describe the Nebular Hypothesis
scientists believe the solar system was created by collisions of gas particles in a huge rotating cloud
List and briefly describe Earth’s four major spheres
Geosphere: solid earth, Biosphere: living organisms, Hydrosphere: water, atmosphere: layer of gases around the earth
Identify and describe the steps of the scientific method
Observation/question, Hypothesis(if/then), Methods, Data/Collection, Results, Conclusion, Control (stays the same for comparison), Theory (hypothesis that has been tested, all other conflicting disproved), Law (mathematically proven)
Compare and Contrast independant and dependant variables
Independent:: What you change, Dependant: Result of change
Identify the 3 components of atoms.
Protons (+) Neutrons (no charge) Electrons (-)
Define an isotope.
Element with the same number of protons but different number of neutrons
Identify the number of protons and neutrons of an element.
atomic number=protons, atomic mass-atomic number=neutrons
Substance that consists of 2 or more elements chemically combined
Describe ionic, covalent, and metallic bonding.
Ionic: gaining/losing electron (between a metal an nonmetal) Covalent: Sharing electrons (between 2 nonmetals or 2 same element) Metallic: Sharing electrons between 2 metals
Describe the conditions that cause chemical bonding.
When an atom’s outer energy level does not have the maximum number of electrons.
List and describe the processes of mineral formation.
Crystallization from magma, precipitation, change in temperature and pressure, formation from hydrothermal solutions
List and describe the methods of mineral identification.
Color, streak (powder form), Luster (shine), crystal form, hardness (Mohs scale), Cleavage (90o breaks), Fracture (uneven breaking), density, other properties
Describe the different groups of minerals and identify examples of each.
- Silicates-silicon and oxygen, ex. Quartz, mica, feldspar
- Carbonates-carbon, oxygen, +other metal ex. Dolomite, limestone, marble
- Oxides-oxygen and metal ex. Rutile, corundum, hematite
- sulfates/sulfides- contain sulfur ex. Galena, pyrite, sphalerite
- Halides-halogen + one other element ex. Halite, fluorite
- Native Elements- gold, silver, copper, carbon
solid mass of mineral or mineral-like matter that exists naturally as part of the planet
Compare/Contrast Minerals and Rocks
minerals are a combination of elements, rocks: combinations of minerals
Identify the 3 types of rocks.
igneous, sedimentary, metamorphic
Describe the rock cycle
An igneous rock forms when magma or lava cools. Over time, the igneous rock is broken down into smaller and smaller pieces, or sediments. The sediments become compacted and cemented together as more time passes and a sedimentary rock is formed. If the sedimentary rock is subjected to intense heat and pressure, it can form a metamorphic rock. The metamorphic rock can become an igneous rock again if it becomes buried deep beneath Earth’s surface and melts into magma.
What are the agents of metamorphism?
heat, pressure, hydrothermal solutions
What is the energy that drives the rock cycle?
the Earth’s core, sun
Describe the different textures and compositions of the different types of rock and give examples of each.
intrusive forms when magma hardens beneath the Earth’s surface while extrusive is when lava hardens Intrusive-Granite Extrusive-Rhyolite
Describe contact metamorphism.
Hot magma moves into rock changes rock it comes in contact with.
Compare foliated and nonfoliated metamorphic rock.
Foliated rocks have a banded appearance, nonfoliated do not
Describe each of the different divisions of the geologic time scale
The biggest units are eons, which are divided into eras. Eras are divided into periods, and periods are divided into epochs
Describe the changes in life and earth during each era/period
- Paleozoic: vertebrates and plants appeared
- Mesozoic: forests developed on land reptiles and dinosaurs became abundant
- Cenozoic: Mammals, birds and flowering plants became abundant
Explain Radioactivity and radioactive dating.
Geologists know the rates of decay for many isotopes. For any rock or mineral sample that contains one of these isotopes, they can compare the ratio of the amount of the parent isotope with the ratio of the amount of the daughter products to find the sample’s age. Sedimentary rocks are made of multiple rocks.
Describe and calculate half life.
half-life is the amount of time necessary for one-half of the nuclei in a sample to decay to a stable isotope.
What principles are the basis for geologists to use for the study of geologic history?
Geologists believe: rock record is evidence of geological life/events and earth is very old and changes due to the same processes that occur today.
Describe the law of supposition, cross cutting relationships, principle of horizontality.
The law of superposition states that in an undeformed sequence of sedimentary rocks, each bed is older than the one above it. The principle of horizontality states that layers of sediment are deposited horizontally. The principle of cross-cutting relationships states that a fault or an intrusion in layers of rock is younger than the rock into which it intrudes.
Describe angular unconformity, disconformity, unconformity.
- Angular Unconformity: Layers of sedimentary rock form over older sedimentary rock layers that are tilted or folded.
- Disconformity:Sedimentary rocks over other sedimentary rocks.
- Nonconformity:erosional surface separates older metamorphic or igneous rocks from younger sedimentary rocks.
What are fossils? What type of rock can they be found in? What has to happen for a fossil to form?
the remains or traces of prehistoric life. Sedimentary Rock. rapid burial and the possession of hard parts.
Identify the different types of fossils.
Cast, mold, trace, petrified, carbon film, Preserved
measurement from crest to crest of a wave
lowest part of a wave
highest part of a wave
amount of time it takes to complete one wave
distance between trough and crest of a wave
a wave that is blown by the wind so its crest is broken and appears white
massive concrete structures emplaced along a considerable stretch of shoreline to protect it from waves
coral reef running parallel to the shore but separated from it by a channel of deep water.
ridge of sand that connects an island to the mainland or to another island
type of motion in which energy travels through waves
What causes waves
What causes currents
density, temperature, rotation of the earth, wind (surface currents)
What causes tides?
moon gravity (some sun)
Compare and contrast neap tides and spring tides.
spring are largest, neap are smallest
a current that flows parallel to the shore and moves large amounts of sediment along the shore
the deflection of currents away from their original course as a result of Earth’s rotation
the rising of cold water from deeper layers to replace warmer surface water
Compare and contrast Sonar, Satelite, and Submersibles
- Sonar-calculates ocean depth by recording the time it takes sound waves to reach the ocean floor and return
- Satellite- measures the height of the ocean surface which is due to the ocean floor features
- Submersibles-a small underwater craft used for deep-sea research. Submersibles are used to collect data about areas of the ocean that were previously unreachable by humans
Compare and contrast the three types of glaciers
- Continental Glaciers (Ice Sheets)-thick sheet of ice that covers a huge area
- Valley glaciers cause formations high in the mountains
- Piedmont glaciers occur when valley glaciers flow onto relatively flat plains
Define Saltation, Suspension, and Deposition
- Saltation-particles bouncing along stream bottom
- Suspension-particles floating in water
- Deposition-particles dropped
What main factor determines a stream’s ability to erode and transport sediment?
Describe the different stream erosion and deposition features.
- Natural levee-sand builds up along a slope
- Delta-large deposit of sediment where a river or stream meets a large body of water
- Alluvial fan-fan shaped deposit of sediment
- Meander-curves of a stream
- Oxbow lake-lake formed from a stream chaning course
- V-shaped valley-valley in mountain carved by a stream
- Waterfall-drop off formed from the erosion of a stream
- Flood plain-flat areas of land
List and describe the two types of glacier erosion.
- Plucking-Lifting of rock blocks
- Abrasion-as slide, work like sandpaper
What is the term for glacial sediment and features caused by glacier erosion and deposition?
Compare and contrast chemical and mechanical weathering
- Chemical weathering more rapidly in high temperatures with abundant rainfall
- Mechanical weathering occurs faster in places where temperature conditions frequently alternate between freezing and thawing
Why are scientists studying data in ice cores? What two types of data are they using?
Using dust particles and conductivity to map out temperature, winds, climate, and volcanic activity in the past
What is a bend in rock layers
Identify and Describe the layers of the earth including the type of rocks each layer is made of
- Crust: granite, outer layer
- Lithosphere: crust & part of mantle
- Mantle: peridotite, includes asthenosphere
- Inner Core: Solid
- Outer Core: liquid metallic ion
Describe Wegener’s continental drift hypothesis and the problems and supporting evidence of it
- Hypothesis: Continents were 1 large piece, plates then moved apart
- Problems: How? What force?
- Evidence: Fossils, fit of continents, rock type & similarities, paleoclimate
Compare and Contrast the different plate boundaries
- Divergent: move apart (constructive)
- Convergent: move towards each other (destructive)
- Transform: slide past each other (conservative)
Identify evidence of seafloor spreading and plate tectonics
Paleomagnetism, Aging of rocks, Earthquake patterns
Describe mantle convection
Through subduction crust pushed down into mantle is cooler and more dense so it sinks and pushes less dense hotter magma upward
Compare and Contrast magma and lava
Magma beneath earth’s surface, lava above
Identify the features of a volcano
Magma chamber- pocket where magma often collects before eruption until pressure builds; Pipe- narrow vertical channel; Vent- opening in the ground where magma escapes to the surface; Crater- bowl shaped pit at top of central vent; Caldera- huge depression at top of volcano-collapse of hollow shell
Identify and describe types of plutons
Sills resemble buried lava flows and may exhibit columnar joints; Laccoliths are lens-shaped masses that arch overlying strata upward; Dikes are tabular-shaped intrusive igneous features that cut across preexisting rock layers; Batholiths are large masses of igneous rock that formed when magma intruded at depth, became crystallized, and subsequently was exposed by erosion
Identify and describe the different types of volcanoes and give an example of each
Shield Volcano-flat, wide, caused by quiet eruption low-viscosity lava ex. Kilauea; Cinder cone- small steep-sided caused by ash and cinders Ex. Utah; Composite- explosive eruptions, combination of lava and ash ex Mt. St. Helens
Identify the factors that influence rock deformation
temperature, confining pressure, rock type, and time
Identify the events that occur at different plate boundaries.
At divergent boundaries, volcanic activity occurs where the plates pull apart.Mantle rock rises to fill the gap between the plates. As the rock rises, decompression melting occurs. This forms magma, which erupts along the axis of the spreading center.Volcanoes form at convergent boundaries where two oceanic plates meet and oceanic lithosphere is subducted beneath another oceanic plate. This process results in the formation of a chain of volcanoes on the ocean floor. Most intraplate volcanism occurs where a mass of hotter-than-normal mantle material, called a mantle plume, rises toward the surface. Once the plume nears the top of the mantle, decompression melting forms magma. The result may be a small volcanic region a few hundred kilometers across called a hot spot.
Define and describe isostacy
Earth’s crust floats on top of the denser and more flexible rocks of the mantle.
Identify and describe the different types of mountains and how they form
Mountains that are formed primarily by folding are called folded mountains; Fault-block mountains are formed as large blocks of crust are uplifted and tilted along normal faults; Uplifted mountains are circular or elongated structures formed by uplifting of the underlying basement rock.
Explain and define accretion.
Accretion is a process that occurs when crustal fragments collide with and stay connected to a continental plate
Explain the different types of folds and faults
Anticlines are most commonly formed by the upfolding, or arching, of rock layers.; Synclines are linear downfolds in sedimentary strata.; Monoclines are large step-like folds in otherwise horizontal sedimentary strata. Normal faults occur when the hanging wall block moves down relative to the footwall block; Reverse faults are faults in which the hanging wall block moves up relative to the footwall block; Thrust faults are reverse faults with dips less than 45o; Strike-slip faults are faults in which the movement is horizontal and parallel to the trend, or strike, of the fault surface
Compare and Contrast Renewable and Nonrenewable resources and give examples of each.
Renewable can be easily replaced/renewed ie. water, wind, solar Nonrenewable cannot or take millions of years to do ie. oil, gas, petroleum
Identify the advantages and disadvantages of solar, wind, water, and nuclear energy.
Solar is free and non polluting, wind is free and non polluting but noisy, an eyesore, and has upkeep, water has upkeep, disrupts the environment and sediment, nuclear energy produces radiation, pollution, and disrupts the environment
How do hydroelectric power, geothermal energy, and tidal power contribute to our energy resources?
hydroelectric =5%, geothermal=very little tidal power=not much but important
What is the chemical composition of the atmosphere?
Nitrogen, oxygen, water vapor, other gases
Identify the major legislation that was put in place to help protect our resources.
- Clean water act: 1970s prevents or decreases point source pollution in surface waters
- Clean air act: 1970s set standards for amounts of pollutants in the air
Explain the process of fission
Nuclei are bombarded with neutrons which cause it to split and releases heat energy and other neutrons