People cross pale limestone blocks separated by deep joints above Malham Cove, England.

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Preparing the 3D view

Preparing lighting and the first complete frame…

Model scale

Selected 60 × 30 m limestone block. relief ×1.3. joints enlarged.

CaCO₃ + CO₂ + H₂O → Ca²⁺ + 2HCO₃⁻. Water containing dissolved CO₂ can dissolve calcite and enlarge connected openings.

How to read these results

The front rock face hides the passage; enable Cutaway to inspect it. Calcite can precipitate from cave water where carbon dioxide escapes.

Karst

Explain how water dissolves limestone along joints to form surface grooves, sinkholes and underground passages.

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Why it happens

Water containing dissolved carbon dioxide can dissolve calcite along joints and bedding planes. Connected openings can develop into underground drainage routes, while calcite may later precipitate where carbon dioxide escapes.

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

Try a comparison

Open Cutaway and follow the selected route towards the spring.

Reading the result

The cutaway illustrates connected passages and the reaction; it does not calculate cave growth rates or water quality.

A common misunderstanding

An underground drainage basin must have exactly the same boundary as the surface basin.

Water in soluble rock can follow connected fractures and passages beneath a surface divide. Its underground route may therefore lead to a different outlet from the one suggested by topography. Dye tracing and other observations can help establish the actual groundwater connections.

Cases

Exam language

Limestone pavement

An exposed limestone surface divided into blocks called clints and solution-enlarged joints called grykes. Glacial stripping can expose the rock, after which chemical weathering enlarges fractures. The pavement records both exposure and later dissolution.

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

Clint

A block of limestone at the surface of a limestone pavement, separated from neighbouring blocks by enlarged joints called grykes. Rainwater containing weak carbonic acid dissolves the rock along those joints and can also carve grooves into each clint.

Gryke

A deepened joint or fissure separating clints on a limestone pavement. Weakly acidic water dissolves limestone along the fracture and widens it. Plants often occupy grykes because they trap soil and offer shelter.

Swallow hole

An opening where a surface stream enters underground drainage, usually in karst. A doline or sinkhole is a depression and need not contain a sinking stream.

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Stream Passage Pot, Ingleborough, North Yorkshire. This entrance belongs to the Gaping Gill karst drainage system, where surface water enters underground passages.

Carbonation

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

Resurgence

A place where water that flowed underground returns to the surface, often as a spring in karst terrain. Tracer studies can link a resurgence to a distant sinking stream. The visible outlet does not reveal the whole underground route.

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Groundwater emerges at a karst spring in Alabama. Water stored in connected pores and fractures can return to the surface as spring flow.

Stalactite

A mineral deposit hanging from a cave roof, commonly formed when dripping water loses carbon dioxide and precipitates calcite. A stalagmite grows upward from the floor. Neither feature is formed by limestone simply melting.

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Stalactites in a cave on Mount Kyllini. Dissolved calcium carbonate is deposited as water drips and loses carbon dioxide.

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