AHigh-altitude origin
BSudden tectonic uplift
CLateral erosion in flat terrain
DOcean current influence
Answer:
C. Lateral erosion in flat terrain
Read Explanation:
River Meanders and Landform Development
Meander Definition: A meander is a winding curve or loop in the course of a river or stream, typically formed in its middle and lower stages.
Primary Cause: Meanders develop primarily due to lateral (horizontal) erosion and deposition occurring in low-gradient or relatively flat terrain.
Mechanism of Formation: As a river flows across a gentle slope, the velocity of the water is uneven. Water moving on the outer bank flows faster, causing intense cut-bank erosion, while the slower-moving water on the inner bank deposits sediment to form a point bar.
Oxbow Lakes: Over time, continued lateral erosion and deposition cause the meander loop to become exaggerated. Eventually, during floods, the river cuts through the narrow neck of the loop, isolating the old curve to form a crescent-shaped body of water known as an Oxbow Lake.
Incised Meanders: When a meandering river undergoes rejuvenation (e.g., land upliftment), it cuts vertically downward into bedrock, forming steep-sided deep valleys known as incised or entrenched meanders.