The presence of 180-million-year-old salt domes in the Gulf Coast region of the United States indicates that
A) the area was once volcanically active.
B) the area was subjected to plate collisions which caused metamorphism to occur.
C) subsidence is now occurring due to the withdrawal of magma from the region.
D) a sea used to cover the area but subsequently evaporated.

Question

Quizplus · Accepted Answer

The presence of 180-million-year-old salt domes indicates that a sea used to cover the area but subsequently evaporated, leaving behind the salt deposits. This process is known as evaporite deposition. The domes are formed by the upward movement of the salt through overlying rock layers due to the salt's buoyancy. This process can occur over millions of years, and the resulting salt domes are commonly used for oil and gas drilling. Volcanic activity and plate collisions do not create salt domes, and subsidence due to the withdrawal of magma is not related to the formation of salt deposits.

The Presence of 180-Million-Year-Old Salt Domes in the Gulf Coast