The question asks about the formation of a V-shaped valley. This is a classic geomorphological feature, and its formation is directly linked to specific erosional agents and stages of landscape development. We need to identify which agent is primarily responsible for cutting downwards into the landscape, creating a steep-sided, V-shaped profile.
C) A river in its youthful (upper) stage. In its youthful stage, a river flows with high velocity over steep gradients, leading to strong vertical erosion (downcutting). This process carves out a narrow, deep channel with steep sides, forming the characteristic V-shape of the valley.
The question asks about the geomorphological agent responsible for forming a U-shaped valley. We need to identify which natural process typically creates this distinct valley shape.
Correct Option: D) Glacial erosion — Glaciers, through processes like plucking and abrasion, widen and deepen existing river valleys, transforming their V-shaped cross-section into a characteristic U-shape with steep sides and a flat bottom.
The question asks for the geographical term describing a deep valley with very steep, often vertical sides. We need to evaluate each option based on its geological definition.
Correct Option: A) A gorge or canyon is a deep, narrow valley with very steep, often vertical sides, typically carved by a river or stream through resistant rock.
The question asks about the primary agent responsible for carving the Grand Canyon. This is a well-known geographical feature, and its formation is a classic example of fluvial erosion.
Correct Option: B) The Colorado River. The Colorado River is unequivocally recognized as the primary geological agent responsible for carving the Grand Canyon over millions of years through a process of downcutting and erosion.
The question asks about the formation of a rift valley. We need to identify the geological process that leads to this specific landform.
D) The sinking of land between two parallel faults — This accurately describes the formation of a rift valley. Tensional forces cause the Earth's crust to pull apart, creating parallel normal faults. The central block of land between these faults then subsides, forming a graben or rift valley.
The question asks about the geological process responsible for the formation of the East African Rift Valley. This requires knowledge of plate tectonics and the types of forces that create major landforms like rift valleys.
Correct Option: C) Tensional (divergent) tectonic forces