Name_________________________________________ Date________________ Period_______ KARST TOPOGRAPHY MAP 8A Mammoth Cave, Kentucky, Figure A In this lab, you will acquaint yourself with karst features as imaged on a map and schematic cross section. Figure A is a cross section showing the various rock types in the Mammoth Cave, Kentucky quadrangle. The Drippings Springs escarpment is named for Dripping Springs found in the northwest quarter of MAP 8A. Using the contour line patterns, the distribution of trees, and Figure A, identify the location of the escarpment on the map. FIGURE A. Schematic cross section 1.) List the rock types present north and south of the escarpment. North? South? Why is the escarpment present? Locate on the map, south of the escarpment feature, the following karst features: sinkhole, water filled sinkhole, solution valley, disappearing stream. Check with your instructor to make sure you have correctly located these features 2). Note that the various karst features are not evenly distributed across the Pennyroyal Plateau. Describe the distribution and grouping of the features you have identified. 3.) Can the distribution you have noted be explained by different stages of karst landscape evolution? Why or why not? 4.) What other geologic factors might be involved? (Hint: note on figure A that layers dip to the NW) 5.) Are there any limits on further development of karst topography? Name_________________________________________ Date________________ Period_______ Mammoth Cave, the largest known cave in the United Sates, is located about 4 miles north of Cedar Hill School. Its position within the sedimentary rocks is shown schematically on Figure A. Locate on the map any karst features present north of the Dripping Springs escarpment. 6.) Given your answers to question 1, why are karst features present north of the escarpment? 7.) Modify Figure A by drawing a line to show the topographic profile in the vicinity of Cedar Hill School. 8.) How might this geologic situation have contributed to the large size of Mammoth Cave? MAP 8B Crystal Lake, FL (1:24,000) 9.) Cedar Creek, in the southwest quadrant of the map, is a disappearing stream. In which direction is Cedar Creek flowing? 10) The Cedar Creek valley is very marshy. Why? 11.) What features suggest that most lakes on the map are sinkholes? 12.) Why do so many of the sinkholes contain water? 13.) Note that River Lake, in the center of the map is more irregular in outline than most other lakes on the map. What does this suggest about the origin of this lake? How would you expect River Lake to change in appearance over time? 14.) Do Crystal Lake and Compass Lake connect underground? Explain your reasoning. Name_________________________________________ Date________________ Period_______ Figure B is a reduced and simplified version of the Crystal lake, FL map. All of the sinkholes that contain water are shown. The water-surface elevations (in meters) of some of the lakes are also shown. These elevations indicate the elevation of the water table where it is exposed in lakes. First, determine additional water-table elevations using Map 8B. To do this, you must count contour lines. In most cases, the nearest heavy contour line around a lakes marks the 20-m interval. Remember that hatch marks indicate a depression so you are moving to a lower elevation as you count lines toward the water surface. Once you have enough points, contour the data with a 2-m contour interval. Remember that contour lines connect points of equal value. the 18-m contour line has been located to help you get started. FIGURE B Name_________________________________________ Date________________ Period_______ Based on the topography of the water table, there are three major flow directions, or "drainage areas" on the map. one is to the northwest, another to the south-southeast and the third to the east. 15.) Calculate the gradient of Cedar Creek from the point it reappears at the 16-m contour line to the point where it leaves the map. How do you think this compares to the hydraulic gradient of the water table in this direction? 16.) Imagine you are going to build a house on the north side of the road at the common corner of sections 1, 2, 35 and 36 in the northwest quadrant of the map. What is the elevation of the building site and the elevation of the water table beneath the building site How deep would you need to drill a well to obtain drinking water? 17.) Should you be concerned about water quality in this area? Explain.