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Preparing the 3D view

Preparing lighting and the first complete frame…

Model scale

Joint opening change ×10. initial joint 20 mm wide. water mass fixed.

Freezing in a joint. Actual joint 20.72 mm · liquid 4.20 L + ice 3.05 L, from 7.00 kg water.

How to read these results

Play illustrates progressive change, not elapsed years. Weathering changes rock in place; erosion transports the resulting material. No automatic fracture threshold is calculated.

Weathering

Compare how freezing water, weakly acidic water and growing roots break down rock in place.

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Why it happens

Weathering changes rock in place. Freezing water, chemical dissolution and biological activity can weaken it through different mechanisms, often acting together before erosion transports the material.

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Weathered granite documented by GeoDIL. Mineral breakdown and disintegration progressively turn intact rock into weathered material.

Try a comparison

Choose Carbonate dissolution and read the reaction and mass balance. Compare Root growth, naming both mechanical and chemical biological effects.

Reading the result

The demonstrations conserve the stated material quantities but prescribe the visible changes rather than calculating a universal weathering rate.

A common misunderstanding

Chemical and mechanical weathering are separate alternatives that cannot act together.

Several weathering processes can affect the same rock. Mechanical cracking exposes new surfaces to chemical reactions, while chemical alteration can weaken material for later breakage. Temperature, water, organisms and rock properties influence which processes are most effective in a particular setting.

Cases

Exam language

Mechanical weathering

The physical breakdown of rock into smaller pieces without changing its mineral composition. Frost action and expansion or unloading can contribute. The fragments remain near their source until erosion transports them away.

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Blockfield on Foel Fras, Wales. Physical weathering breaks bedrock into angular fragments without changing its minerals.

Chemical weathering

The alteration or dissolution of minerals through chemical reactions with water, gases and dissolved substances. Carbonation, hydrolysis and oxidation are examples. Unlike mechanical weathering, these reactions change mineral composition as well as the appearance of the rock.

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Malham Cove limestone pavement. Rainwater containing dissolved carbon dioxide widens joints into grykes, leaving blocks called clints.

Biological weathering

The breakdown or chemical alteration of rock caused by organisms. Roots can widen fractures, while organic acids from plants and microbes react with minerals. These effects overlap with mechanical and chemical weathering rather than forming an entirely separate mechanism.

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Roots grow through existing rock joints. Their growth can widen cracks, contributing to biological and physical weathering.

Frost shattering

Rock breakdown associated with freezing water and ice growth in cracks. Repeated freezing, thawing and ice segregation can widen the fractures.

Carbonation

Chemical weathering in which dissolved carbon dioxide forms weak carbonic acid that reacts with carbonate minerals such as calcite.

Weathering

Physical breakdown or chemical alteration of rock at or near Earth's surface, without transporting the material away. Chemical weathering also participates in the carbon cycle.

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Weathered granite documented by GeoDIL. Mineral breakdown and disintegration progressively turn intact rock into weathered material.

Erosion

The wearing away and removal of material by moving water, wind, ice or gravity. Weathering breaks down material in place.

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Presque Isle River, Michigan. Sediment circulating in eddies abrades the bedrock, enlarging these potholes.

Process0.40Mechanism