Formations in Redcliffe Caves

Straw stalactites growing from the Railway Style Arch in Redcliffe Caves.
The straws are formed from water percolating though the concrete in between the bricks and picking up a mineral called gypsum.
As each drip falls the gypsum is re deposited in the form of a straw stalactite. These straws are hollow, the water running down the centre of the straw, and are very fragile.
The straws grow very quickly approximately a foot (12 inches) every 10 years. There are similar formations in natural caves but the mineral that forms the straws is calcium carbonate - these straws grow very slowly
To protect these straws from being broken a scaffolding and chicken wire cage was built around them.
Photograph : Eric Burke(Mole) (2005)