Fact 1: Stalactites are formed by deposition.

Fact 2: Inside the caves are some young stalactites and stalagmites in formation.

Given the two facts above, answer the question "what causes formations in caves" with the following options: 
- Water expanding
 - calcite
 - oxygen
 - erosion
 - nitrogen
 - deposition
 - less water
 - carbon dioxide


 

      deposition   