Mass movements, erosion, and deposition

In mass movement, rock and soil move downslope mainly due to gravity. For exams, remember mass movement is gravity-driven.

Rock fall involves sudden falling of rocks from a steep or vertical slope. In exams, treat it as a rapid mass movement.

Soil creep is the extremely slow downslope movement of soil. In exams, tilted poles and bent trees are common indicators.

Debris flow occurs when water-mixed rock, soil, and sediment move rapidly downslope. For exams, water saturation is a key cause.

Steep slopes and heavy rainfall can weaken soil and trigger downslope movement. Link slope, rainfall, and gravity in exam answers.

Undercutting removes support at the slope base and increases landslide risk. For exams, connect undercutting with slope instability.

Weathering breaks rocks in place, while erosion removes and transports the broken material. Remember the in-place versus transport difference.

In abrasion, the river load rubs against the bed and banks and cuts them. Remember it as the river's tool effect.

A steep gradient in the upper course gives the river power to cut downward. In exams, link the upper course with deep valleys and waterfalls.

In attrition, particles collide and become smaller and rounder. In exams, rounded pebbles indicate river transport.

In solution, soluble materials are carried dissolved in water. For exams, remember solution especially in limestone areas.

When velocity decreases, a river loses carrying capacity and deposits sediment. In exams, connect deposition with loss of energy.

During floods, the river spreads over its banks and deposits fine alluvium. Treat floodplains as river depositional features in exams.

A delta forms by deposition of sediments at a river mouth. In exams, link calm water and high sediment load with delta formation.

When slope suddenly decreases, the river deposits coarse sediment in a fan shape. Link mountain-to-plain transition with alluvial fans.

In deflation, wind removes loose fine particles from the surface. In exams, remember deserts and wind erosion together.

Sand particles near the ground abrade more strongly, so the lower part of the rock is cut more. Mushroom rock is a wind abrasion feature.

When wind velocity decreases, it deposits sand and forms dunes. In exams, connect dunes with wind deposition.

A glacier scrapes the bed with rocks carried within it. Striated rocks are evidence of glacial abrasion in exams.

Moraine is unsorted debris transported and deposited by a glacier. In exams, connect unsorted sediments with glacial deposition.

A glacier widens and deepens a valley to form a U-shaped valley. Remember river valleys as V-shaped and glacial valleys as U-shaped.

Hydraulic action of waves and abrasion by pebbles erode the coast. In exams, link coastal erosion with wave energy.

Waves enlarge weak zones and can turn caves into arches. Remember the sequence cave, arch, and stack for exams.

A beach forms by deposition of sand and pebbles by waves and currents. It is a simple example of coastal deposition.

Groundwater dissolves limestone and forms karst landforms. For exams, link limestone, solution, and karst.