Common Misconceptions

⚠️ Common Misconceptions

Misconception 1: "U-shaped valleys have a V-shaped cross-profile like river valleys."

This is one of the most common errors in glacial landform answers. Rivers erode primarily downward (vertical erosion), cutting V-shaped valleys with sloping sides that meet at a point at the bottom. Glaciers erode both downward AND laterally (sideways), widening the valley floor while steepening the sides. The result is a broad, flat floor with near-vertical walls joining it at approximately right angles — the U-shape. Another giveaway: U-shaped valleys often have tiny rivers (misfit streams) flowing through an oversized valley. No river is capable of carving a flat floor hundreds of metres wide — but a glacier certainly is. When describing or drawing a U-shaped valley, emphasise the flat floor and straight, steep sides — not sloping sides converging at a V.

Misconception 2: "Drumlins are formed by erosion, like corries."

Drumlins are entirely depositional — they are made of glacial till that was deposited and shaped by moving ice. They are not carved out of rock. The confusion arises because drumlins look like hills of rock sticking up from the landscape, and because abrasion does contribute to their streamlining. But the material that makes up a drumlin is till (unsorted glacial sediment), not bedrock. The ice deposits till around a rocky obstacle or reshapes existing till mounds, streamlining them in the direction of flow. No rock is removed by erosion to create a drumlin — material is added by deposition.

Misconception 3: "Corries only form on north-facing slopes in the UK."

This is misleading rather than entirely wrong. In the UK, corries do predominantly face north or northeast because these aspects receive less direct sunlight, meaning snow accumulates and persists better. However, the statement "only north-facing" is too strong. Some corries in the UK face other directions where other local factors (sheltering from wind, valley topography, altitude) compensated for greater solar heating. For exam answers, the correct statement is: "Corries tend to form on north- and northeast-facing slopes in the UK because these aspects receive less direct sunlight, so snow accumulates and is less likely to melt." Avoid saying "always" or "only north-facing."

Misconception 4: "The pointed end of a drumlin is the direction the glacier came from."

This gets it exactly backwards. The blunt, steep stoss face points INTO the direction from which the ice came — the glacier hit the stoss face first. The pointed, gently tapering lee face points in the direction the glacier was travelling. A useful analogy: imagine a teardrop shape, or a boat in water — the blunt bow faces the oncoming flow (wind or water), and the tapered stern trails behind it. So if you see a drumlin with its blunt end pointing north, the ice came from the north and flowed south. Always remember: stoss = upstream (ice source); lee = downstream (ice travelled toward).