diapir
/ˈdaɪəˌpɪr/
noun
- A mass of rock or sediment that moves upward through surrounding layers, often forming a dome or plug.
- The oil company drilled near a diapir because such structures often trap petroleum.
- A salt diapir can push up through the earth and create a hill.
- Geologists studied the diapir to understand how underground pressure shapes the landscape.