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5.10: Lab Exercise (Part D and E)

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    5521
  • Part D – Karst Topography

    Use the Mammoth Cave, Kentucky map (Map 5.4 located at the end of this chapter) to answer the following questions. Though it is old (1922), the general geology and landforms in this area have not changed.

    21. Locate Little Sinking Creek in the southern portion of the map, north of Hwy. 68 and south of the Edmonson County Line. In which direction does it flow?

    a. South                         b. North                         c. Southeast                         d. Northwest

     

    22. Follow the creek along its path. Where does it wind up?

    a. Along Hwy. 68            b. It disappears underground.

     

    23. Find Sloans Crossing. It is south of Mammoth Cave. What is the benchmark elevation at Sloans Crossing?

    a. 600’                           b. 630’                           c. 800’                                d. 834’

     

    24. Now, look farther south of Sloans Crossing at Hwy. 31W. Look closely at the topography south of the highway as it changes abruptly. What feature(s) can you observe south of Hwy. 31?

    a. Sinkholes                         b. Disappearing streams                         c. Generally lower land surface elevations                         d. All of the above

     

    25. Keeping the abrupt topography change in mind, which of the following is true? a. In the northern portion of the map, the area is underlain by limestone b. In the southern portion of the map, the area is underlain by limestone 26. Locate the Louisville and Nashville Railroad line just south of Hwy. 31. Would this be an easy location to maintain a railroad?

    a. Yes                             b. No

     

    26. Locate the Louisville and Nashville Railroad line just south of Hwy. 31. Would this be an easy location to maintain a railroad?

    a. Yes                             b. No

     

    Part E – Google Earth

    The exercises that follow the use of Google Earth. For each question (or set of questions) paste the location that is given into the “Search” box. Examine each location at multiple eye altitudes and differing amounts of tilt. For any measurements that use the ruler tool, this can be accessed by clicking on the ruler icon above the image.

    Search for 7 26 16.49S 75 00 00.06W and zoom out to an eye altitude of 15 miles.

    27. How would one describe this river?

    a. Straight                         b. Meandering                         c. Low sinuosity                         d. Braided

     

    28. In this stream, erosion is occurring on the ______________ because _______________, while deposition is occurring on the _____________________ because ______________________.

    a. point bars; the fastest velocity water flows to this point; cut banks; the slowest velocity water flows to this point

    b. point bars; the slowest velocity water flows to this point; cut banks; the fastest velocity water flows to this point

    c. cut banks; the fastest velocity water flows to this point; point bars; the slowest velocity water flows to this point

    d. cut banks; the slowest velocity water flows to this point; point bars; the fastest velocity water flows to this point

     

    Search for 63 55 55.23N 17 01 07.14W and zoom out to an eye altitude of 10,000 feet.

    29. How would one describe this river? 

    a. Straight                         b. Meandering                         c. Low sinuosity                         d. Braided

     

    30. What factors control the course of this river?

    a. Steep gradient and high discharge                                 b. Low gradient and low discharge

    c. Low gradient and abundant sediment supply                   d. Steep gradient and low sediment supply

     

    Search for 38 01 12.18N 121 43 20.02W and zoom out to an eye altitude of 30,000 feet.

    31. The river in this area has a rather particular pattern, what geologic process caused this?

    a. a meander eroded through its bank and created an oxbow lake

    b. the river is in a karst terrain and disappeared into the ground

    c. the river is following patterns, likely faults, in the underlying bedrock

    d. during a flood the river breached the natural levee flowing into the floodplain

     

    32. Zoom out and examine the surrounding area, what geological hazards are likely in the area?

    a. sinkholes                         b. flooding of urban areas                         c. erosion and subsidence                         d. none of the above

     

    Search for 41 24 30.77N 122 11 46.23W and zoom to an eye altitude 50,000 feet.

    33. What type of drainage pattern is present in this area?

    a. Trellis                             b. Dendritic                                              c. Rectangular                                         d. Radial                                           e. Deranged

     

    34. What does this type of drainage pattern indicate about the area?

    a. rocks in the area are homogeneous and/or flat-lying                              b. rocks in the area are alternating resistant and non-resistant, forming parallel ridges and valleys

    c. stream channels radiate outward like wheel spokes from a high point      d. stream channels flow randomly with no relation to underlying rocks or structure

     

    Search for 36 45 41.23N 85 18 34.22W and zoom out to an eye altitude of 25,000 ft. Although there is no stream present today, the stream channels can be clearly seen.

    35. What type of drainage pattern was present in this area?

    a. Trellis                             b. Dendritic                                              c. Rectangular                                         d. Radial                                           e. Deranged

     

    36. What does this type of drainage pattern indicate about the area?

    a. rocks in the area are homogeneous and/or flat-lying                              b. rocks in the area are alternating resistant and non-resistant, forming parallel ridges and valleys

    c. stream channels radiate outward like wheel spokes from a high point      d. stream channels flow randomly with no relation to underlying rocks or structure

     

    37. In what direction was the main river flowing?

    a. West                             b. East                             c. North                             d. South

     

    Search for 28 38 01.92N 81 22 44.78W and zoom out to an eye altitude of 13,000 ft.

    38. How were these lakes formed?

    a. they were man-made – all are dammed                                                                  b. they are formed by large rivers in the area

    c. as sinkholes, as underlying soluble rock was dissolved and areas collapsed                 d. they are impact structures that filled with water

     

    39. What type of bedrock is present in this area?

    a. Limestone                             b. Sandstone                              c. Gneiss                                    d.Granite                                 e. Chert

     

    Now let’s travel to Mars! Mars has shown evidence of water, and NASA and others have been studying Mars intensely in recent years. Let’s look at a few features on Mars. In the location toolbar across the top of Google Earth, locate the image that looks like the planet Saturn. Click the button to bring up several location options and select Mars. In the Layers box on the left, notice Global Maps. You may have to click on it to expand it. For today, we will use the highest quality images found in the Visible Images layer. The other layers are interesting, but won’t be used today.

     

    In the Search tab, type in Noctis Labyrinthus and zoom to ~300 miles.

    40. These features you are seeing are linear valleys. Assume that water flowed through these valleys at some time. What type of drainage pattern would this area represent?

    a. Trellis                             b. Dendritic                                              c. Rectangular                                         d. Radial                                           e. Deranged

     

    41. Think about the drainage pattern you selected in the previous answer – what does this tell you about the underlying rocks?

    a. The rocks are probably fractured.

    b. The rocks are uniformly resistant.

    c. The rocks are part of a topographic high, like a mountain. 

    d. The rocks are alternately resistant and non-resistant In the Search tab, type in Warrego Valles and zoom to ~120 miles.

     

    42. Notice the general shape of this feature. It is thought to have formed by the runoff of either precipitation or groundwater. What type of drainage does this appear to be?

    a. Trellis                             b. Dendritic                                              c. Rectangular                                         d. Radial                                           e. Deranged