|Perfect Number of Pages to Order||5-10 Pages|
Robert Trommer is the student’s name. Robert J. Sager, Ph.D.
MIDTERM EXAM IN GEOLOGY 100 (20 percent of course grade)
PART A: INTERPRETATION OF A CROSS-SECTION OF STRATIGRAPHY (10 percent )
In this activity, apply the scientific method to interpret geologic data/information. From prior assignments, the online textbook, course “Webliography” (Content tab), and online geologic research sources, the student should study the themes presented on rocks (igneous, sedimentary, and metamorphic rocks) and geologic time. At the end of the questions, you must list your research sources in APA-style citations.
Based on your understanding of the geologic cross-section, answer the following questions (Figure 1)
on the first page
1) How would you relate Fig. 1’s layers (strata) to the “principle of original horizontality”? From B to M, use the strata (includes B-K-N-J-D-M). Explain.
The basic horizontality principle states that sediment layers are always deposited horizontally under gravity. As a result, the layers in the figure must have been subjected to the horizontal deposition because they are horizontal in nature.
The elder beds are placed beneath the younger ones according to the idea of original horizontality. Above all of the beds lies the youngest formation. The oldest is found beneath all horizontal beds. As a result, the youngest beds are at the top of the horizontal beds, while the oldest is at the bottom.
You have demonstrated how to apply the idea of original horizontality to the beds B-K-N-J-D-M in the statement.
Bed B is located above all of the horizontal beds in the above rock series. As a result, it will be the youngest of all the rock beds.
Because it rests beneath the rock bed B, K is older than B.
Because it rests beneath the rock bed K, N is older than K.
Because it rests beneath the rock bed N, J is older than N.
Because it resides beneath the rock bed J, D is older than J.
Because it exists at the bottom of all horizontal beds, M is the oldest of all the given beds in B-K-N-J-D-M.
2) How would you apply the “superposition principle” to the layers (strata) in Fig. 1? From B to M, use the strata.
(containing the letters B-K-N-J-D-M) Which strata are the oldest and which are the youngest? Explain.
The superposition principle states that older rock is always covered by younger rock. Every other rock in the B, K, N, J, D, M strata is overlaid by rock M, and along these lines, rock M is the oldest, followed by D, J, N, K, and finally B.
3) Which letter corresponds to the surface cover? What exactly would this be made up of? What could be the origins of this surface material? Why isn’t this included in the sedimentary rock strata?
The letter F represents the surface cover, which is made up of loose sediments known as soil. This
4) What is the definition of a geologic “unconformity”? Is there anything out of the ordinary about this stratum sequence? If so, what kind of disobedience are they? Describe the location of at least two (2) unconformities, if any, in the stratigraphy (between letters).
A geologic unconformity is a break in the rock sequence that indicates a break in the sedimentation process, which is usually accompanied by erosion of the strata below the break. A nonconformity between A and N and a disconformity below layer N and above layer J are the two forms of
Is rock region A made of intrusive or extrusive igneous rock? What kind of common igneous rock do you think it’s made of? What is the name of this massive igneous feature?
would be an igneous rock that would be intrusive. Granite is a common igneous rock that it would be made of. Batholith is the name given to this enormous igneous structure.
6) If some metamorphic rock existed in the sedimentary strata from B to M, which strata (identify by letter) would have had the most contact metamorphism with A? Explain.
D, N, and K are the letters of the alphabet. Metamorphism happens as a result of natural forces such as heat and pressure, and it affects nearby pre-existing rocks.
Citations in APA format:
PART B. TECTONIC PLATE BOUNDARY EXERCISE AND SEISMIC PROFILE (10 percent )
In this activity, apply the scientific method to interpret geologic data/information. The student should go over the Plate Tectonics themes covered in prior assignments, the online textbook, the course “Webliography” (Content tab), and other online geologic research materials that cover plate tectonics and earthquakes dispersion. Your research sources, including any websites you consulted, must be cited in APA-style citations.
Earthquake data was obtained from a local seismograph network during a 32-month period. There were a total of 2,476 seismic events recorded, and you will be plotting and evaluating 30 of the most dependable earthquakes.
Table 2 displays just the earthquake foci locations that occur within the line of the cross-section in Figure 1 at latitude 20oS in the master data set. An earthquake’s focus (plural foci) or hypocenter is the point below the surface where the earthquake occurred. The epicenter is the point directly above and at the surface of the focus.
Place a dot on the cross-section of Figure 2 at the correct location for each earthquake focus to plot the earthquake data from Table 2. The x-axis represents longitude, and the y-axis represents the depth of the foci. (Note that you can scatter plot immediately on the doc. cross-section or hand plot and copy before attaching to your test.) doc)
oW Depth, Longitude (km)
oW Depth, Longitude (km)
oW Depth, Longitude (km)
68 -18 66 -24
65 -29 68 -28 65 -25
71 -15 67 -21 73 -8
67 -20 68 -20 63 -33
70 -12 72 -6 67 -23
72 -9 66 -26 66 -22
68 -23 69 -20 72 -12
71 -10 67 -25 64 -30
65 -27 70 -14 71 -9
64 -32 70 -17
Table 2 shows statistics on earthquake foci observed along the plane of Figure 2’s cross-section.
Figure 2: A cross-section of the 20oS latitude (the 20S) parallel (longitude X, depth Y).
Answer the following questions on the data (Pages 3 and 4):
Based on your completed Figure 2 on Page 4, answer the following questions.
1) Determine the plate tectonic boundary type for this location based on the pattern that developed when you displayed the earthquake foci data (Figure 2) on Page 4. Draw a possible plate boundary (a trend line) on the cross-section and use arrows to depict the direction of motion of each plate.
2) Describe the geologic processes and activity that this sort of tectonic boundary is connected with.
3) Examine the area for geologic dangers. Name three geologic dangers that might occur in this area.
a. Eruption of a Volcano
4) What is the latitude and longitude of this plate boundary? In terms of geography, where does this plate boundary lie?
5) What are the names of the two tectonic plates that make up the plate border that is located there? (See Figure 2.) What key geologic features are likely to emerge? You can utilize graphics to back up your answer.
Citations in APA Format: