The process in which concentrated shells of rock may spall from the outside of an outcrop or a boulder is known as:

Correct option is B

1. Exfoliation:
· Exfoliation is a mechanical weathering process in which thin, curved layers or shells of rock are peeled away from the surface of an outcrop or boulder.
· This process occurs due to changes in temperature, pressure release, or both, causing the rock to expand and contract, resulting in the spalling of outer layers.
2. Incorrect Options:
· (a) Leaching: Refers to the removal of soluble materials from soil or rock by percolating water, not a mechanical weathering process.
· (c) Frost wedging: Occurs when water freezes in cracks of rocks, expanding and causing the rock to fracture. It does not lead to shell-like spalling.
· (d) Disintegration: A general term for the breakdown of rocks into smaller fragments but does not specifically describe the peeling of outer layers.
Information Booster: 1. Causes of Exfoliation:
· Pressure Release: Rocks formed under high pressure deep in the Earth's crust expand as overlying material is removed, leading to spalling.
· Thermal Expansion: Repeated heating and cooling cycles cause rocks to expand and contract, resulting in outer layers breaking off.
· Chemical Weathering: Can weaken the outer layers of rocks, making them more susceptible to exfoliation.
2. Famous Examples:
· Yosemite National Park: Features large exfoliation domes.
· Sugarloaf Mountain, Brazil: Formed due to exfoliation processes.
3. Difference from Other Processes:
· Frost Wedging: Involves water freezing and expanding within cracks.
· Leaching: Chemical process involving the removal of minerals.
· Disintegration: Refers to the general breakdown of rocks into fragments.