Recall from your reading about the nature of volcanoes to choose the best answer: Magma tends to rise toward Earth’s surface principally because __________.
of convection in the mantle
|of magma cooling|
|mounting pressure within the reservoir|
|rocks become more dense when they melt|
Recall from your reading about the nature of volcanoes to choose the best answer: Which type of basaltic lava flow has a fairly smooth, unfragmented, ropy surface?
Refer to the following relative time scale diagram to answer the question: which of the following represents the longest subdivision of the geologic time?
Recall from your reading about the nature of volcanoes to choose the best answer: A volcanic eruption is driven by __________ and __________ which forces its way upward and may ultimately break though zones of weaknesses in the Earth’s crust.
buoyancy; water pressure
|heat; water pressure|
|heat; gas pressure|
|buoyancy; gas pressure|
Recall from your reading about the relative time scale and refer to the following diagram of a composite geologic section to answer the question. Which of the following is the oldest rock layer observed in the diagram?
Bright Angel shale
· Recall your reading of Relative Time Scale and Radiometric Time Scale and match the term with the definition.
|A.||Isotope found in all living plants and animals|
|B.||Atoms of the same element with differing atomic weights|
|C.||The Scottish geologist who first proposed the fundamental principle used to classify rocks according to their relative ages|
|D.||Studies on the origins of the various kinds of rocks|
|E.||The time it takes for one-half of a particular radioactive isotope in a sample to decay|
|F.||Studies of rock layering|
|G.||Forms of life which existed during limited periods of geologic time and thus are used as guides to the age of the rocks in which they are preserved|
|H.||Rocks that generally do not contain fossils|
· Recall from your reading of Principal Types of Volcanoes, and match the description to the type of volcano.
|Large, fairly steep-sided cones composed of alternating layers of lava flows and pyroclastic material.|
|Small basaltic cones built during one, short, eruptive episode; dominated by cinders.|
|Volcanoes of southwestern Alaska and the Aleutian Islands.|
|Big volcanoes of Hawaii|
|Volcano Paricutin in Mexico|
|Forms dikes from lava|
|Lava is produced after the eruption and flows from the bottom|
Volcanoes with gentle slopes spreading over large areas
· Recall from your reading about the radiometric time scale to put the following isotopes in order of use, from oldest rock to youngest.
According to the figure below, give an approximate age for the Dakota Sandstone and for the Wasatch Formation. Explain what evidence you used to determine this.
Recall from your reading about the nature of volcanoes, and in your own words, compare and contrast aa and pahoehoe lava in appearance and how they form.
In your own words, briefly explain how a caldera forms from principle types of volcanos.
Volcanoes are generally not preserved in the geologic rock record because they are usually eroded away. However, the various materials erupted from volcanoes are often found preserved in the rock record. From what you have learned about the different principle types of volcanoes, how could you infer what type of volcano erupted in a given area based on the type of volcanic deposits now found as layers of rock? Give specific examples, and briefly discuss how some materials may be linked to different types of volcanoes. Your response should be at least 200 words in length.
The 2011 earthquake and tsunami in Japan have raised new concerns about the safety of nuclear energy. While countries like the US have started new nuclear power plant construction (in Georgia), and India plans to build the world’s largest nuclear facility near the west coast port of Jaitapur, Germany recently announced that it will close its nuclear power plants by 2022 (as now has Japan). If the US does re-start its nuclear energy program full-force (beyond the upcoming plants in Georgia), what can the US nuclear industry learn from recent events in Japan? If you were a consulting geologist hired to join a team charged with assessing the feasibility of new nuclear plant construction, what geological factors would you consider in siting a plant? Are there any geologically safe places to build a nuclear plant?
Your response should be at least 200 words in length.