Final answer:
Half Dome in Yosemite National Park was shaped by uplift during the Cretaceous period followed by exfoliation and glacial erosion which resulted in its distinctive rounded top and steep sides.
Step-by-step explanation:
Half Dome, a renowned feature of Yosemite National Park, was formed through a combination of geologic processes. The Sierra Nevada, where Half Dome is located, underwent significant uplift during the Cretaceous period due to tectonic forces.
This uplift exposed granite rock to surface conditions, leading to weathering and erosion. Half Dome's characteristic shape is primarily the result of exfoliation, a process where sheets of rock peel away from the granite dome due to pressure release. Furthermore, glacial action during the Ice Ages carved and smoothed the rock, giving Half Dome its unique and striking appearance.
While studying various national parks, it's noted that significant uplifts, such as that seen in Yosemite, occur due to the movement beneath the Earth's surface, related to the shifting of the Earth's crustal plates. This movement can cause folding, warping, and fracturing of the crust, a set of processes which are integral to the formation of the Sierra Nevada Range and features within it like Half Dome.