Which process was not likely involved in the formation of Half Dome?

• A. Glacial erosion
• B. Volcanic eruption
• C. Exfoliation
• D. Weathering

Answer: (B)

The formation of Half Dome, a prominent granite rock formation in Yosemite National Park, is primarily attributed to geological processes involving glacial erosion, exfoliation, and weathering. Each of these processes played a significant role in shaping the landscape.

Glacial erosion occurred as glaciers advanced and retreated through the Sierra Nevada, carving out valleys and shaping the peaks. This process is crucial in creating the distinct features seen in Half Dome today.

Exfoliation refers to the peeling away of rock layers due to physical weathering, often caused by temperature changes. This process contributed to the rounded appearance of Half Dome, as outer layers of rock were stripped away, revealing the granite core.

Weathering, both chemical and physical, also played a foundational role in breaking down the rock material and shaping the mountain's structure over time.

In contrast, while volcanic activity has shaped many geological formations, Half Dome's characteristics do not stem from volcanic eruptions. The rock formation is primarily composed of granite, rather than volcanic rock, indicating that volcanic processes were not involved in its creation. Thus, the answer identifies the absence of volcanic activity as a key factor in understanding the geological history of Half Dome.