Term
| Given that Earth and its neighbors lie near the Sun, these planets have become enriched in dense elements because light-weight elements were blown away during early solar explosions. The explosions preferentially removed more volatile elements and concentrated elements with high melting temperatures (refractory elements). All but one of the following elements became concentrated in Earth. The one that did not become concentrated by this process is ... |
|
Definition
|
|
Term
2.For at least the past 4 billion years, Earth has been differentiated into a core, mantle, and crust. Chemical elements have preferentially migrated into each of these concentric shells during the "cooking" of Earth. Differentiation probably continues today but most migration of chemical elements occurred during early cooking of Earth. Because of this differentiation, uranium is most concentrated (proportionately) in the .... |
|
Definition
|
|
Term
| Vertical cross-section of the earther. Earth has an average radius of 6400 km. The proportinal of the total radius of the earth is roughly.... |
|
Definition
|
|
Term
| before aggregating into the sun and planets, the chemical elements were collected into a swirling cloud. Despite gravitational attraction which tended to induce aggregation of the materials, aggregation was resisted for a long time because... |
|
Definition
gravitational force was resisted by a tendency of the swirling objects to move along a tangent to their curved paths (a tendency called the centrifugal effect) |
|
|
Term
Fig. 3 illustrates a continental shelf like that of North Carolina. If you were to sail from Wilmington, North Carolina due east to the shelf break (the seaward edge of the continental shelf), you would have to travel about |
|
Definition
|
|
Term
| continental crust averages about 4 times thicker than oceanic crut. Feldspar is the dominant mineral in both types o f crust but there is a compositional difference between the 2 enviroments. The difference is that in continental crust the feldsbar has more of.... |
|
Definition
|
|
Term
| Most maps that show the Earth's lithospheric plates use the Mercator projection. Of the following lithospheric plates, which one has its area most enlarged (relative to true area) by this type of projection? The plate that is most enlarged on a Mercator-projection map is the |
|
Definition
|
|
Term
| Atoms ionize to achieve number of electrons in their outermost shell. Elements which are much bigger than hydrogen either donate or accept electrons to achieve the favored number of 8 outmost eletrons. Chlorine achieves eight out shell electrons by.... |
|
Definition
|
|
Term
| In a three-dimensional framework such as quartz or the feldspars, the characteristic ratio of tetrahedral corners to centers is |
|
Definition
|
|
Term
| Fig. 5 illustrates Bowen's Reaction Series. Bowen experimentally showed that feldspars form a continuous reaction series as temperature changes, i.e., a reaction series in which |
|
Definition
| the crystallographic structure does not change much while chemical composition changes |
|
|
Term
| The most siliceous magmas contain about 70% SiO2 component whereas the least siliceous basaltic magmas contain about …… |
|
Definition
|
|
Term
| Fig 7 illustrates the double-chain structure which is characteristic of the mineral group called the amphiboles. The characteristic ratio of tetrahedral croners to tetrahedral centers in amphiboles is.... |
|
Definition
|
|
Term
| Most of the gas which emanates from volcanic magma is composed of |
|
Definition
|
|
Term
| Pillow basalt can only form if lava erupts onto |
|
Definition
| the floor of a body of water |
|
|
Term
| During chemical weathering, soluble elements are removed by groundwater and insoluble elements accumulate within soil. Which of the following elements is the least soluble and therefore most likely to accumulate within soil? |
|
Definition
|
|
Term
| The type of soil that experiences the most shrink-swell activity is Vertisol |
|
Definition
| a type of soil that is more common in the Western US than in the Eastern US |
|
|
Term
| The chemical reaction which converts potassium feldspar into kaolinite involves both hydration and hydrolysis. Kaolinite is Al2 Si2 O5 [OH]4. Which of the following is the formula for potassium feldspar? Choose among |
|
Definition
|
|
Term
| Some weathering reactions produce a mineral as |
|
Definition
| as one of the reaction products |
|
|
Term
| Erosion of rock or soil by water movement, by wind, or by glaciers produces loose particulate matter which is collectively called detritus. This material eventually settles to become clastic sediment. Clastic sediment generally occurs as extensive layers called beds. These beds typically are .. |
|
Definition
| a few centimeters to tens of meters in thickness. |
|
|
Term
| The stiffening of sediment into solid rock (lithification) occurs progressively upon burial. The three dominant diagentic processes which induce lithification are compaction, recrystalization, and....... |
|
Definition
|
|
Term
| Marine evaporite deposits mostly consist of halite [table salt, composed of NaCl] and gypsum. Gypsum has the chemical formula of |
|
Definition
|
|
Term
| Marine evaporite deposits mostly consist of halite [table salt, composed of NaCl] and |
|
Definition
|
|
Term
| One of the following temperatures lies within the realm of diagenesis instead of metamorphism. All others lie within the realm of metamorphism. The diagenetic temperature is.. |
|
Definition
|
|
Term
| Fig. 10 illustrates a cliff with horizontal sedimentary beds which are cut by igneous bodies. Rock unit B most likely is |
|
Definition
|
|
Term
| Fig. 12 shows a hillside with only one grain that is being affected by freeze-thaw action. If you were an educator, you might be inclined to show just one grain being affected this way ….... |
|
Definition
| despite the fact that this would be misleading, given that all grains on the hillside would be affected by freeze-thaw action ... |
|
|
Term
| Boulders in a rock glacier commonly sit on a slope which obviously is steeper than the angle of repose. The reason that the boulders do not fall is |
|
Definition
| that they are embedded in ice which does not extend to the surface of the boulders. |
|
|
Term
| Specify which of the following causes initiated the mass-wasting even which killed over 20,000 residents of Armero, Colombia in 1985. Choose among …./ |
|
Definition
|
|
Term
| The material which has accumulated at the base of the cliff illustrated in Fig. 13 would be called |
|
Definition
|
|
Term
| Fig. 14 illustrates several well-defined regions within a typical subsurface hydrologic regime. Designated letters refer to the water table, saturated zone, and zone of aeration. Determine which letter labels the zone of aeration. Choose .... |
|
Definition
|
|
Term
| When the continental glaciers finally melted about 10,000 years ago, many of the transported blocks came to rest on bedrock which is composed of rock types that are quite different from those of the transported blocks. Early-nineteenth-century geologists realized that the blocks must have come from a distant source. They therefore named them erratics, after the latin verb, errare, which means .... |
|
Definition
|
|
Term
| Consider a glacier which has plastered sediment underneath it as it has moved. Suppose that the plastered sediment covers all valleys as well as hilltops and therefore has a surface topography which is unrelated to that of underlying bedrock. Such a layer is called ........ |
|
Definition
|
|
Term
| The enormous size and power of glaciers makes them formidable modifiers of the landscape, both as erosional and depositional agents. In some cases, a glacier may initially deposit a large mass of sediment and then continue to move over it, sculpting it into a streamlined hill that is more than 100 m long. The result is a ........ |
|
Definition
|
|
Term
| Despite having a large range in grain size, the average size of grains within a layer of glacial sediment typically remains roughly the same throughout the layer, from bottom to top. In contrast, sediment deposited from landslide events (both on land and submarine) typically becomes progressively finer grained upward through the bed. This tendency for fining upward is caused by a progressive decrease in flow rate as the mass-wasting event comes to an end. The resulting fining upward in grain size is called ......... |
|
Definition
|
|
Term
| Fig. 15 shows that a snow fence may impede drifting sand. As in Canada, where this type of fence impedes drifting snow, one is most likely to see this fence in an arid region ... |
|
Definition
|
|
Term
| Arid areas in North America tend to be mountainous, e.g. Death Valley along the California-Nevada border. This mountain-desert association is ... |
|
Definition
| partially relevant to the location of arid regions because of the orographic effect on the distribution of rainfall |
|
|
Term
. Fig. 16 illustrates
[image] |
|
Definition
|
|
Term
| Sand inherently forms dunes, whether deposited from water or wind. Dunes generally consist of two surfaces, one inclined upwind and the other (the slip face) downwind. Deposition on these surfaces produces a sedimentary structure within sandstone. This sedimentary structure is called... |
|
Definition
|
|
Term
| Of all the land area of hot deserts throughout the world, roughly what percentage is not covered by dune sand? The percentage lies in the range of |
|
Definition
|
|
Term
| Suppose that you have gone backpacking in a desert and it starts to rain heavily late at night while you are camped on a narrow dry valley floor between two beautiful mountains. The first thing that you should think about is that you .. |
|
Definition
| should head for higher ground |
|
|
Term
| Imagine that you were to travel to the middle of the Atlantic Ocean along the equator and then descend to the bottom of the ocean at that locality within a submarine to measure the temperature on the deep seafloor (under several kilometers of seawater). Which of the following temperature ranges would you most likely measure there? Choose among ... |
|
Definition
|
|
Term
| Tides are illustrated in Fig. 17. A complete explanation for the existence of tides on Earth involves .. |
|
Definition
| local imbalances between the gravitational and centrifugal effects of the Earth-moon-Sun system. |
|
|
Term
| Like the moon, the Sun exerts gravitational attraction on planet Earth and its hydrosphere. As illustrated in Fig. 18, the Sun's influence seasonally augments or diminishes the lunar effect. The highest amplitude of tidal range throughout the year occurs when the Sun and the moon are aligned with the Earth, producing Spring Tides. Compared to that of the moon, the influence of the Sun on tides is |
|
Definition
|
|
Term
| Laminar flow is a basic concept in fluid dynamics. In laminar flow, individual droplets of water travel in predictable paths. Laminar flow is …. |
|
Definition
|
|
Term
| Laminar flow is a basic concept in fluid dynamics. In laminar flow, individual droplets of water travel in predictable paths. Imagine water velocity increases beyond that of a laminar flow. A fluid dynamicist would say that the flow has passed from being laminar to being |
|
Definition
|
|
Term
| The pH of rivers generally is |
|
Definition
| greater than the pH of the rainfall which feeds the rivers. |
|
|
Term
| Once pores lose their groundwater and collapse, pumping water back into the subsurface will not reverse the resulting subsidence of buildings. However, it should slow it. The world's most voluminous urban example of pumping-induced subsidence has occurred in Mexico City. Among the following cities or regions in the USA, which one has experienced the most-substantial pumping-induced subsidence? Choose among |
|
Definition
| Great Valley of California. |
|
|
Term
| Once pores lose their groundwater and collapse, pumping water back into the subsurface will not reverse the resulting subsidence of buildings. However, it should slow it. The world's most voluminous urban example of pumping-induced subsidence has occurred in Mexico City. All of the following factors have contributed to this subsidence except... |
|
Definition
| intensive burrowing of the aquifer by termites |
|
|
Term
| A few years ago, more snow fell during the winter in Upstate New York than ever before in recorded history (past 400 years). At 18 ka, Upstate New York was buried under glacial ice which probably exceeded 2 km in thickness. Do you think that 18,000 years ago this area had more snow in mid-winter (February) than during the record-setting February a couple of years ago? At 18 ka, this area had... |
|
Definition
| about the same amount of snow fall every February (somewhere between three times more and three times less). |
|
|
Term
| Fig. 15 illustrates the general principle that the surface of a water table is a subdued reflection of overlying landscape topography. Suppose that the US Dept. of the Interior needed water to fight a huge forest fire and pumped the lake dry in the illustrated area to get water for their fire-bombing airplanes. What would be the expected consequence of their action? One would expect that eventually |
|
Definition
| the lake would rise to 100% of its previous level …. |
|
|
Term
| Twenty thousand years ago, there were glaciers sitting on the sides of all the tall mountains along the western coast of North America, from Washington State through coastal Canada to Alaska. These glaciers have left amphitheater-shaped erosional features on the sides of all of those mountains. |
|
Definition
|
|
Term
| In the northern hemisphere of Fig. 16, there is a wavy line which stretches all the way from the left side toward the right side of the figure, separating the low-pressure from high-pressure regions. This wavy line most closely corresponds to the ... |
|
Definition
|
|
Term
| Gravitational attraction between the Earth and moon may be analyzed using Isaac Newton's famous equation, Fg = κ * [m1 * m2 ] / r2. In this equation, the “ κ " stands for |
|
Definition
| a proportionality constant. |
|
|
Term
| Which of the following types of sand dune illustrated in Fig. 15 most consistently occurs in a semi-arid coastal environment with persistent on-shore wind (and is rare elsewhere)? Choose among |
|
Definition
|
|
Term
| Reefs are composed of a wide variety of animals and plants which precipitate calcium carbonate from warm seawater. Algae and colonial animals, e.g. corals, have dominated reefs throughout the past half-billion years. However, corals cannot grow within a deltaic area primarily because... |
|
Definition
| corals are filter feeders |
|
|
Term
| Consider the path of a drop of water at the very top of the crest in the center of Fig. 19. That drop would be travelling |
|
Definition
| horizontally to the right |
|
|
Term
| The Kuroshio and Gulf Stream are northward-flowing marine currents which lie along the western boundaries of the Pacific and Atlantic oceans, respectively. The reason that these northward-flowing currents lie along the western boundaries of the Pacific and Atlantic oceans is that .. |
|
Definition
| the Earth rotates toward the east |
|
|
Term
| . If you wanted to find an extensive fringing reef in the USA, the best place to go would be .... |
|
Definition
|
|
Term
| Carbon dioxide has a detectable effect on the temperature of Earth's atmosphere despite the fact that it is scarce, constituting a volume percent of only 0.035%. Although the concentration of atmospheric carbon dioxide is very low when compared to nitrogen or oxygen, it is greater than that of all of the following atmospheric gases except |
|
Definition
|
|
Term
| Carbon dioxide is considered to be a greenhouse gas because it.. |
|
Definition
| temporarily absorbs long-wavelength radiation and then radiates it in all directions. |
|
|
Term
| Fig. 17 illustrates a plunging anticline and adjacent syncline. Where in North Carolina are you most likely to see such folded rock layers? Choose among ....... |
|
Definition
| watauga county (Appalachain St.) |
|
|
Term
| To find a reverse fault in the field (Fig. 21), it would be best to travel to a .... |
|
Definition
|
|
Term
| The magnetized stripes in Fig. 22 indicate that ... |
|
Definition
| plate velocity toward the right is roughly the same as toward the left. |
|
|
Term
| A common type of seismograph has a weighted pen which dangles loosely onto a rotating drum. The paper-lined drum vibrates with the shaking ground but the pen does not vibrate much during the earthquake because of its inertia. Although still popular in textbooks, this type of seismograph effectively has been replaced by |
|
Definition
| an electric version which uses neither a pen or a paper-lined drum |
|
|
Term
| If you had your choice of places to be during the disaster illustrated in Fig. 25 (within the illustrated area), your best choice would be to be ....../ |
|
Definition
| on the far right of the sketch |
|
|
Term
| Most fatalities in modern earthquakes result from the collapse of structures onto people. A peculiarity of collapse during some Chinese earthquakes is that a small proportion of the Chinese have lived within man-made caves dug into wind-deposited silt (loess). Collapse of these cave walls is more likely to cause |
|
Definition
| suffocation than is collapse of building walls |
|
|
Term
| Seismic waves are affected by layering such as the core-mantle boundary. Besides the major layering of the deep Earth, lesser differentiations within the Earth also induce changes in seismic-wave velocity. One such zone extends from about 100 km to 350 km beneath the Earth's surface. S waves are particularly affected during travel through this depth range. The effect on S waves is to induce |
|
Definition
| a lower than expected velocity |
|
|
Term
| Each day, every person on Earth consumes enough energy (on average) to burn 22 light bulbs continuously, day and night. To calculate the total global consumption of energy, one would have to |
|
Definition
| multiply these 22 bulbs by the number of people on Earth |
|
|
Term
| Important ore deposits of the chemical element, lithium, occur west of Charlotte, NC. Consider the geologic environments in which these ore deposits have formed |
|
Definition
| granitic plutons in continental crust |
|
|
Term
| The best types of ore contain |
|
Definition
| little gangue per cubic meter mined |
|
|
Term
| Fig. 27 (copied above) shows that manganese may be concentrated in the environment where oceanic crust is moving due to plate tectonics. Most of this manganese occurs as |
|
Definition
|
|
