Salt domes are large underground formations created when salt deposits, often from ancient seas, are pushed upward through layers of rock due to pressure. This process can create a dome-like structure, where the salt rises and can become trapped beneath other geological layers. These formations are significant because they can store natural resources, such as oil and natural gas, making them important for energy production. Additionally, salt domes can also be used for underground storage of hazardous materials and natural gas, providing a safe and efficient way to manage these resources.