Exfoliation is the primary weathering process leading to rock-slides in Yosemite Park, caused by the release of pressure on granitic rock as overlying materials erode away.
In Yosemite Park, the dominant weathering process that weakens granitic rock, resulting in frequent rock-slides is exfoliation. This process occurs due to the release of pressure on the granitic rock as overlying materials are eroded away over time, causing the rock to peel off in layers or sheets.
Weathering and erosion are integral in shaping the Earth's landscape, leading to the creation of soil from disintegrated rock fragments of varying sizes. Factors that contribute to weathering include mechanical processes like ice wedging, and chemical processes such as the dissolution by acidic rain.
Exfoliation is particularly significant in Yosemite due to the type of rock and the climatic conditions. The granitic formations, after being subjected to immense pressure at depth, begin to expand when that pressure is released, which can cause the rock to fracture and peel away in sheets, a process that is enhanced by the wide temperature fluctuations in the region.
Therefore, while other weathering processes such as ice wedging and chemical weathering also play a role, exfoliation is the primary factor contributing to rock-slides in Yosemite Park.