Geologists reveal the ‘master sculptor’ behind the world’s dramatic sandstone formations

Arches 'carved' from sandstone are found all over the world

It’s long been thought that the arches, columns and bridges of natural sandstone formations were created by years of erosion from wind and rain, but new research suggests that these fantastic shapes are actually the product of gravity instead.

Scientists from the Charles University of Prague explain that it’s not that erosion doesn’t play its part, but that it is the rock’s “internal stress fields” – the different areas of pressure caused by weight and gravity - that dictate the final form.

“Erosion gets material out, but doesn’t make the shape,” explains Jiri Bruthans, a hydrogeologist who led the research. Instead, he says, the wind and the rain are merely the “tools” that reveal the shape that is latent in the rock.

Dr Bruthans began his research after visiting the Stralec Quarry in the Czech Republic and observing the unusual properties of a type of sandstone known as “rock sand”. Bruthans noticed that although the miners had to use dynamite to break the rock walls apart, once they had the material itself just crumbled apart - often leaving behind the arches and bridges seen in natural sandstone formations.

The team from Prague took away blocks of rock sand from the quarry to conduct their own experiments, exposing the samples to cycles of heat, cold and salt to simulate natural erosion, and even leaving one block out in the rain for 15 months to see if it would form a natural arch.

They found that by placing weights and pressures on the material they could accurately predict how arches, alcoves and other features would form, baking cubes of the rock sand in the oven to harden it then dunking it under water to watch erosion take place.

One of the rock sand cubes and the arch it formed after being squeezed by weights and submerged underwater. Image credit: Marek Janac

"You can control it completely," Dr Bruthans told the BBC. "You select the pillar direction, by choosing the points where you apply the compression. It's just the stress which controls the shape - nothing else."

In an article written to accompany the research in Nature Geoscience, Professor Chris Paola of the University of Minnesota described the discovery as "a lovely and elegant formative mechanism for a lovely and elegant kind of landform".

"These natural sculptures have delighted countless visitors, some of whom must have paused to wonder where they come from," said Professor Paola. "Here is an answer."

Start your day with The Independent, sign up for daily news emails
PROMOTED VIDEO
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
Arts and Entertainment
Under the skin: Sarah Kane in May 1998
theatreThe story behind a new season of Sarah Kane plays
Arts and Entertainment
Preening: Johnny Depp in 'Mortdecai'
filmMortdecai becomes actor's fifth consecutive box office bomb
Sport
Bradford City's reward for their memorable win over Chelsea is a trip to face either Sunderland or Fulham (Getty)
football
News
Lars Andersen took up archery in his mid thirties
video
Voices
Focus E15 Mothers led a protest to highlight the lack of affordable housing in London
voicesLondon’s housing crisis amounts to an abuse of human rights, says Grace Dent
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Warehouse Operations & Logistics Manager

£38000 - £42000 per annum: Recruitment Genius: One of the UK's best performing...

Recruitment Genius: GeoDatabase Specialist - Hazard Modelling

£35000 - £43000 per annum: Recruitment Genius: Our award-winning client is one...

Recruitment Genius: Compressed Air Pipework Installation Engineer

£15000 - £21000 per annum: Recruitment Genius: This leading provider of Atlas ...

Recruitment Genius: Operations Coordinator - Pallet Network

£18000 - £20000 per annum: Recruitment Genius: Opportunity to join established...

Day In a Page

Woman who was sent to three Nazi death camps describes how she escaped the gas chamber

Auschwitz liberation 70th anniversary

Woman sent to three Nazi death camps describes surviving gas chamber
DSK, Dodo the Pimp, and the Carlton Hotel

The inside track on France's trial of the year

Dominique Strauss-Kahn, Dodo the Pimp, and the Carlton Hotel:
As provocative now as they ever were

Sarah Kane season

Why her plays are as provocative now as when they were written
Murder of Japanese hostage has grim echoes of a killing in Iraq 11 years ago

Murder of Japanese hostage has grim echoes of another killing

Japanese mood was against what was seen as irresponsible trips to a vicious war zone
Syria crisis: Celebrities call on David Cameron to take more refugees as one young mother tells of torture by Assad regime

Celebrities call on David Cameron to take more Syrian refugees

One young mother tells of torture by Assad regime
The enemy within: People who hear voices in their heads are being encouraged to talk back – with promising results

The enemy within

People who hear voices in their heads are being encouraged to talk back
'In Auschwitz you got used to anything'

'In Auschwitz you got used to anything'

Survivors of the Nazi concentration camp remember its horror, 70 years on
Autumn/winter menswear 2015: The uniforms that make up modern life come to the fore

Autumn/winter menswear 2015

The uniforms that make up modern life come to the fore
'I'm gay, and plan to fight military homophobia'

'I'm gay, and plan to fight military homophobia'

Army general planning to come out
Iraq invasion 2003: The bloody warnings six wise men gave to Tony Blair as he prepared to launch poorly planned campaign

What the six wise men told Tony Blair

Months before the invasion of Iraq in 2003, experts sought to warn the PM about his plans. Here, four of them recall that day
25 years of The Independent on Sunday: The stories, the writers and the changes over the last quarter of a century

25 years of The Independent on Sunday

The stories, the writers and the changes over the last quarter of a century
Homeless Veterans appeal: 'Really caring is a dangerous emotion in this kind of work'

Homeless Veterans appeal

As head of The Soldiers' Charity, Martin Rutledge has to temper compassion with realism. He tells Chris Green how his Army career prepared him
Wu-Tang Clan and The Sexual Objects offer fans a chance to own the only copies of their latest albums

Smash hit go under the hammer

It's nice to pick up a new record once in a while, but the purchasers of two latest releases can go a step further - by buying the only copy
Geeks who rocked the world: Documentary looks back at origins of the computer-games industry

The geeks who rocked the world

A new documentary looks back at origins of the computer-games industry
Belle & Sebastian interview: Stuart Murdoch reveals how the band is taking a new direction

Belle & Sebastian is taking a new direction

Twenty years ago, Belle & Sebastian was a fey indie band from Glasgow. It still is – except today, as prime mover Stuart Murdoch admits, it has a global cult following, from Hollywood to South Korea