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160 Cards in this Set
- Front
- Back
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Atoms of the same element (zinc, for example) have the same number of |
Protons in the nucleus |
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An atom's mass number is 13 and its atomic number is 6. How many neutrons does it contain? |
7 |
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What is the color of a finely powdered mineral? |
Streak |
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What mineral characteristic depends on the strength of internal atomic bonds? |
Hardness |
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What results from weak planes in a mineral's crystal structure? |
Cleavage |
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What depends on the interaction of light with the mineral's surface? |
Luster |
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What is NOT true for minerals? |
They can be solid, liquid, or gas |
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In which type of chemical bonding are electrons shared between adjacent atoms? |
Covalent |
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The nebular hypothesis proposes that all the bodies in the universe formed about 5 billion years ago from a rotating cloud of gases and dust. (True or False) |
False |
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Sphalerite (ZnS) would be grouped in the same mineral class with what mineral? |
Chalcopyrite (CuFeS2) |
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After World War II, scientists conducted sonar surveys of the ocean floor and obtained drill core of oceanic crust to age date. What observation made by these scientists would most strongly support the Sea Floor Spreading hypothesis? |
Moving away from a mid-ocean ridge, the sediment layer gets thicker and rocks get older. |
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What energy source is thought to drive the motion of of Earth's lithospheric plates? |
Export of heat from deep in the mantle to the top of the asthenosphere |
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New oceanic crust and lithosphere are formed at __________. |
Divergent boundaries by submarine eruptions of basaltic magma |
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Cooler, older oceanic lithosphere sinks into the mantle at ______________. |
Subduction zones along convergent plate boundaries. |
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Deep ocean trenches are surficial evidence for ____________. |
Sinking of oceanic lithosphere into the mantle |
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A tabular discordant body that is produced as magma is injected into fractures would be called what? |
Dike |
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What plate tectonic setting is the San Andreas Fault? |
Transform boundary |
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What plate tectonic setting is East Africa? |
Continental rift zone |
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What plate tectonic setting is the Aleutian Islands? |
Subduction Zone |
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What plate tectonic setting is the Himalayas? |
Continental collision zone |
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What plate tectonic setting is Hawaii? |
Hot spot |
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The asthenosphere is also a part of the __________ of the Earth. |
Mantle |
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The _________ is thought to be a liquid, metallic region in the Earth's interior. |
Outer Core
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The ________ is the thinnest layer of the Earth. |
Crust |
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The _________ is the rocky layer that makes up most of the Earth's volume. |
Mantle |
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If non-silicate minerals account for only 8% of the crust, what makes them considered important minerals? |
Many non-silicates are valuable economically. |
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___________ can be paraphrased as "the present is the key to the past." |
Uniformitarianism |
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__________ was based on a belief in a very short geologic history for Earth. |
Catastrophism |
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What statement about the rock cycle is NOT correct? |
Sedimentary rocks may weather to igneous rocks |
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Who proposed the Theory of Continental Drift? |
Alfred Wegener |
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What lines of evidence was NOT offered in support of the Theory of Continental Drift? |
Sediment on the ocean floor was thinner than expected. |
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What describes why the Continental Drift hypothesis was rejected when it was first proposed? |
A mechanism capable of moving continents could not be identified. |
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What describes the configuration of magnetic patterns associated with mid-ocean ridges? |
Normal and reversed magnetized strips roughly parallel to the ridge axis. |
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What is NOT associated with a mid-ocean ridge? |
Old, cold oceanic crust |
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Continental rifting can be correlated with what tectonic event? |
"Birth" of an ocean basin |
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What CANNOT be used to measure the speed and direction of plate motions? |
Seismic waves generated by earthquakes |
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Which magma is most likely to solidify to a natural glass (i.e. obsidian) without any crystals? |
Highly viscous, cools quickly |
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What best describes the cooling history implied by a porphyritic texture? |
Magma cools slowly in a magma chamber for a while, then erupts |
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Which of the following pairs correctly match intrusive and extrusive rock types of an equivalent magma composition? 1. Gabbro; rhyolite 2. Peridotite; pegmatite 3. Diorite; andesite |
Diorite; andesite
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What best describes how most magma is generated along divergent boundaries? |
Pressure lowers as mantle rises, causing decompression melting |
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What term is defined as changing the composition of magma by incorporating surrounding host rock? |
Assimilation |
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Which type of basaltic lava flow has a fairly smooth, ropy surface? |
Pahoehoe |
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What best describes the way that magmas evolve during crystallization? |
Early crystallization of iron- and magnesium- rich minerals causes magma to become more felsic |
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Which magma type is the most abundant at oceanic spreading centers. |
Basaltic |
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Two factors that tend to increase the explosive potential of a magma body beneath a volcano are: |
High viscosity and high gas content |
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Bombs are ejected as magma lumps; blocks are ejected as solid fragments. (True or False) |
True |
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Which type of volcano is typically very large, with gently sloping sides, and composed mainly of basaltic lava? |
Shield volcano |
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Mount St. Helens is a good example of what type of volcano? |
Composite cone |
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Crater Lake, OR is best explained as |
A circular depression formed by collapse after the explosive ejection of magma from a volcano. |
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Weathering is the transportation or removal of broken-down minerals. (True or False) |
False |
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What is an important, mechanical weathering process for enlarging fractures and extending them deeper into large boulders and bedrock? |
Frost Wedging |
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Clay minerals forming from feldspars is an example of which specific weathering mechanism? |
Hydrolysis |
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What is the most susceptible to chemical weathering by dissolution? |
Calcite |
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What two factors increase the rates of chemical reaction and weathering in rocks and soils? |
High temperatures; Very moist conditions |
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What environmental condition is reduced on on a batholith in order to generate weathering via sheeting? |
Pressure |
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______________ weathering occurs when differences in resistance or environmental factors produce uneven surfaces on rocks and rock layers. |
Differential |
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What environment would a breccia most likely be deposited in? |
Steep mountains |
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What rock type is composed of calcium carbonate? |
Travertine |
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One of the most common minerals in detrital sedimentary rocks is _________ because ___________. |
Quartz; it is resistant to mechanical and chemical weathering |
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What best describes the texture and composition of a conglomerate? |
Rounded fragments; poorly sorted |
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Detrital sedimentary rocks are classified (named) based on the ______________. |
Grain sizes of the detrital particles |
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What type of transportation and deposition applies to the basic constituents of halite and rock gypsum? |
Transported as dissolved ions; deposited by evaporation |
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What rock type was most likely deposited close to its source? |
A poorly-sorted breccia |
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What sedimentary structure can most effectively be used to determine ancient current direction? |
Cross-bedding |
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Turbidites are _________. |
Graded beds of shale and graywacke deposited by underwater landslides |
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Peat deposits originate in ___________. |
Freshwater or coastal swamps and bogs |
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What structure represents the single most common and characteristic feature of sedimentary rocks? |
Strata separated by bedding planes |
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______________ is the process where sediments are converted into a sedimentary rock. |
Lithification |
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____________ is the process by which new mineral grains form as a result of metamorphism. |
Recrystallization |
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What platy, parallel mineral grains compose the foliation of schist |
Micas |
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What rock type is characterized by segregation of light and dark colored minerals into think layers or bands? |
Gneiss |
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What two metamorphic rocks are composed predominantly of single minerals? |
Marble and quartzite |
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What could be the parent rock for a marble? |
Fossiliferous limestone |
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What would exhibit highly sheared and mechanically fragmented rocks? |
Fault movements at shallow depths |
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List the following rocks in order by increasing metamorphic grade from left to right: Phyllite, Slate, Schist |
Slate, Phyllite, Schist |
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What is the major source of heat for contact metamorphism? |
Heat from a nearby magma body |
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In which setting would regional metamorphism be most likely? |
At great depths in the crust where two continents are colliding. |
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A metamorphic index mineral _________. |
Provides information about the pressure and temperature conditions during metamorphism. |
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In which geologic setting is the most widespread occurrence of hydrothermal metamorphism? |
Along the mid-ocean ridge systems |
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Which statement best describes the relationship between the composition of protoliths (parent rocks) and the composition of the metamorphic rocks they become? |
Chemical compositions are often nearly the same |
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The most important factor driving metamorphic reactions is pressure. (True of False) |
False |
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Upon low-grade metamorphism clay group minerals would be most likely to recrystallize into which of the following minerals? |
Muscovite |
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What type of metamorphic rock would result from the complete melting of the metamorphic rock gneiss? |
An igneous rock would result |
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Foliated textures are primarily the result of heat. Nonfoliated textures are primarily the result of directed pressure. (True or False) |
False |
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What is the definition of relative dating? |
Putting events in order from first to last |
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What fundamental concept states that in a horizontal sequence of conformable sedimentary strata, each higher bed is younger than the bed below it? |
Law of Superposition |
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___________ is a buried surface of erosion that separates older rocks below from younger sedimentary strata above. |
An unconformity |
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What term refers to the investigative process by which geologists identify and match sedimentary strata and other rocks of the same ages in different areas? |
Correlation |
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A rock is measured to have the following isotopic ratio: 40% (parent) and 60% (daughter). How many half-lives have elapsed since the material was 100% parent atoms? |
between 1 and 2 |
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What is a fossil? |
Evidence of past life that can include skeletal as well as trace material |
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What is an index fossil? |
Organisms that were geographically widespread but limited to a short span of geologic time |
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A _______________ is a type of unconformity with parallel sedimentary strata above and below a surface. |
Disconformity |
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What geologic observation would not bear directly on working out the sequence of geologic events in an area? |
The feldspar and quartz contents of a granite |
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Sandstone strata and a mass of granite are observed to be in contact. Which statement is correct geographically? 1. The sandstone is younger if the granite contains sandstone inclusions. 2. The granite is older if it contains inclusions of sandstone. 3. The granite is older if the sandstone contains pebbles of the granite. |
3. The granite is older if the sandstone contains pebbles of the granite. |
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Which one of the following statements regarding rock deformation and strength is correct? 1. Rocks undergo plastic deformation less readily as temperatures and pressures increase. 2. Brittle and plastic deformation occur when stresses exceed the elastic limit of a material. 3. Elastic deformation is accomplished through internal flow material. |
2. Brittle and plastic deformation occur when stresses exceed the elastic limit of a material. |
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Rocks subjected to heat will be more likely to go through brittle deformation when stressed because the minerals become crystallized. (True or False) |
False |
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What stress situations result in folding of flat-lying, sedimentary strata? |
Horizontally directed; compressive stresses |
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A ___________ fault has little or no vertical movements of the two blocks. |
Strike Slip |
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____________ is the angle of inclination of the surface of a rock unit measured from a horizontal plane. |
Dip |
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____________ is the compass direction of the line produced by the intersection of an inclined rock layer with a horizontal plane. |
Strike |
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The deeper strata are buckled upward along the fold axis. (This is true for anitclines or synclines?) |
Anticline |
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A transform fault is ________________. |
A strike-slip fault that forms the boundary between tectonic plates |
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In a __________ fault, the hanging wall block moves up with respect to the footwall block. |
Reverse |
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The Michigan geologic map shows older Paleozoic strata (in roughly circular patterns) surrounding a core central area of younger Pennsylvanian rocks. What is this structure? |
Basin |
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In thrust faulting, the crust is ______________ and ________________. |
shortened; thickened |
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How many hinge lines does a monocline have? |
Two |
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Jointing in rocks is characterized by __________________________. |
Roughly parallel fractures separating blocks that show no displacement. |
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Which tectonic boundary is associated with compressional stress? |
Convergent |
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Which tectonic boundary would have many normal faults associated with it? |
Divergent |
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Monitoring foreshocks has become a reliable indicator indicator for predicting earthquakes. (True or False) |
False |
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Energy is stored in rocks adjacent to the site of a future earthquake as ______________. |
Elastic Strain |
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_____________ have the highest velocities through the earth and arrive first at a seismic station |
Primary waves |
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The ______________ is a direct measure of the distance from a seismic receiving station to the location of a distant earthquake. |
Time interval between the first P and S wave arrivals |
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The _______________ magnitude scale is a measure of the energy released. It does not directly measure the extent of building damage or the intensity of ground shaking. |
Richter |
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How was the Turnagain Heights neighborhood (now known as Earthquake Park area) of Anchorage, Alaska, damaged during the 1964 earthquake? |
A weak, subsurface clay layer liquefied and failed, resulting in extensive slumping and earth flow. |
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The largest amplitude round shaking is produced by _____________. |
horizontally vibrating surface waves |
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One sign of a tsunami's approach to a coastal area may be a rapid retreat of water from the shoreline. (True of False) |
True |
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What factor does not influence mass wasting? |
Geologic age |
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What is the angle of repose? |
The steepest slope angle at which an unconsolidated material remains at rest |
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A stream is cutting into a valley wall. What is the most likely trigger for a mass-wasting event? |
The stream erodes the toe of the slope, which results in the slope becoming oversteepened. |
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___________ denotes the exposed, crescent-shaped feature that follows a slump. |
Scarp |
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What best describes where the sediment production zone is located along a river? |
Near the headwaters |
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How does urbanization affect runoff and infiltration in a small, previously forested drainage basin? |
runoff increases, infiltration decreases |
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A braided stream is most likely found in what location? |
Flowing from the terminus of a glacier |
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What correctly describes how properties of a stream channel tend to change from the source of a stream to its mouth? |
gradient decreases, discharge and channel width increase |
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What factor is the most important for determining a stream's ability to carry sediment? |
Flow velocity |
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What common, rock-forming mineral is most readily dissolved by groundwater? |
Calcite |
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____________ is the volume of voids or open space in a rock or unconsolidated material. |
Porosity |
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_________ and ____________ are characteristics found in all good aquifers. |
High porosity and high permeability |
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Excessive groundwater withdrawals can cause ______________________________. |
the water table to lower in elevation |
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If an aquifer is pumped faster than it is recharged a _________ will result. |
cone of depression |
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The hot spring deposits at Mammoth Hot Springs in Yellowstone National Park are travertine. What rock-type probably lies somewhere beneath the hot springs? |
Limestone |
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Which material would make the best aquitard? Gravel, Sandstone, Shale, Conglomerate |
Shale |
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What groundwater feature forms where the water table intersects with the Earth's surface, creating a natural outflow of groundwater? |
Spring |
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What geologic process is responsible for the geothermal energy potential of Iceland? |
Volcanic activity and magma at shallow levels in the crust |
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What environmental issue will most commonly affect groundwater aquifers in coastal or island areas. |
Saltwater contamination |
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A _____________ is an isolated remnant of bedrock standing above a wave-cut platform. |
Sea stack |
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Erosional retreat of a ____________ leads to enlargement and extension of a wave-cut platform in the inland direction. |
Wave-cut cliff |
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____________ are currents that move sand and water parallel to the beach. |
Longshore |
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Currents and sediment transport parallel to the coastline is fundamentally caused by _________________________. |
offshore waves approaching at an angle to the soreline |
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What term describes the bending of waves to become more parallel to the shoreline? |
Refraction |
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Which one is NOT directly related to the bending of waves as they approach the shoreline?
Wave speeds decrease as waves enter shallow water; Waves of oscillation erode the seafloor; Deposition is concentrated in bays and protected waters. |
Waves of oscillation erode the seafloor |
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Is this an emergent or a submergent coastline:
Wave cut (eroded) bedrock cliffs, sea stacks, and elevated wave-cut platforms (marine terraces) |
Emergent |
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Is this an emergent or a submergent coastline:
Areas of large estuaries, coastal swamplands, and barrier islands |
Submergent |
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Is this an emergent or a submergent coastline:
The eastern coastline of the continental U.S. |
Submergent |
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What is true about the Mississippi delta: (1) Coastal erosion and loss of delta lands will ___________________________. (2) The sediment supply has ______________ since large reservoirs were constructed on the Missouri and Arkansas Rivers. (3) The thick sediment pile is slowly ______________ and the delta is slowly ______________. |
(1) continue as sea level continues to rise (2) dropped (3) compacting; subsiding |
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What makes a valley glacier lengthen (advances its terminus downslope) over a period of many years? |
Accumulation exceeds wastage |
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What shape will glacial troughs generally display? |
U |
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What material is an arete made of? |
Solid Rock |
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What material is a moraine made of? |
Till |
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What material is a roche moutonee made of? |
Solid Rock |
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What material is a cirque made of? |
Solid Rock |
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What material is an esker made of? |
Stratified Drift / Outwash |
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What material is a horn made of? |
Solid Rock |
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What material is a drumlin made of? |
Till |
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What type of moraine would be most useful for tracing diamond-bearing rocks directly to their bedrock source area? |
Lateral, valley glacier |
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Why are eskers near Palmer, AK economically important? |
Provide easily accessible sand and gravel deposits |
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When was the last glacial maximum in North America? |
18,000 years ago |
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The channeled scablands in eastern Washington State were formed by what event? |
Flooding due to draining of an ice-dammed lake in Montana as a lobe of ice repeatably advanced and retreated |
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How does isostatic rebound affect a glacial landscape? |
The crust which is depressed into the mantle will slowly will rise after glacial retreat. |
