TPO16-L1 Lechuguilla Cave
Listen to part of a lecture in a geology class.
- What is the main purpose of the lecture?
- A. To explain the various ways that sulfuric acid is involved in the formation of caves.
- B. To describe caves and other geologic formations in U.S. national parks.
- C. To use Lechuguilla Cave as an example of how most caves form.
- D. To discuss the formation and characteristics of an unusual type of cave.
- The professor mentions parts of the process involved in the formation of Lechuguilla Cave. Indicate which of the statements below describe part of the process.
|Gypsum residue accumulated to form decorative structures||A||B|
|Gas generated by bacteria reacted with gypsum deposits||A||B|
|Hydrogen sulfide gas mixed with underground water||A||B|
|Acid dissolved parts of the limestone||A||B|
|Bacteria fed on underground oil||A||B|
|Flowing surface water enlarged the cracks in the limestone||A||B|
- According to the professor, what substance found in surface water is important for the formation of typical limestone caves?
- A. Gypsum.
- B. Oxygen.
- C. Carbonic acid.
- D. Sulfuric acid.
- What does the presence of gypsum in Lechuguilla Cave indicate?
- A. The cave was not formed by flowing water.
- B. The cave is no longer forming.
- C. Bacteria are present in high concentrations inside the cave.
- D. No type of acid was involved in the formation of the cave.
- What can be inferred from be fact that Lechuguilla Cave is no longer forming?
- A. The cave has stopped attracting visitors.
- B. The cave no longer contains any limestone.
- C. The air in the cave is safer to breathe now than it was in the past.
- D. Gypsum deposits inside the cave are growing thicker.
- What does the professor mean when he says this: 🎧
- A. Lechuguilla Cave is not completely absent of water.
- B. Lechuguilla Cave is not totally safe to explore.
- C. Water long ago flowed through Lechuguilla Cave.
- D. Scientists do not agree about how Lechuguilla Cave was formed.