Caprock

Caprock or cap rock is a more resistant rock type overlying a less resistant rock type,^[1] analogous to an upper crust on a cake that is harder than the underlying layer.

Description

The

In processes such as scarp retreat, the caprock controls the rate of erosion of the scarp. As the softer rock is cut away, periodically the caprock shears off. Caprock is also found in salt domes and on the top of mesa formations.

Petroleum

In the

The tops of salt domes such as in the Gulf of Mexico dissolve in a characteristic manner, and can range between 0–1500 ft thick.^[2] The halite (salt) is removed first, leaving behind gypsum and anhydrite. The anhydrite and gypsum react with organic material to form calcite. The classic Murray 1966 paper^[3] describes the generalized sequence as sediments-calcite-gypsum-anhydrite-salt.

See also

• Caprock Canyons State Park and Trailway
• Caprock Escarpment
• Hoodoo (geology)
• Monadnock

References