Great forces have formed
the caves of Wookey Hole.
About 400 million years
ago an ocean covered this part of England. Microscopic sea
creatures swam in its waters, and their shells eventually
became calcium carbonate, or limestone, which settled on the
bed of the ocean to mix with and, eventually hardening into
rock.
Powerful internal pressures
squeezed that ocean bed like a crumpled rug to form the Mendip
Hills. As the rain fell on these hills, so it began to dissolve
the weaknesses in the rock, little by little widening cracks,
eating into softer parts, turning into rivulets and streams.
Deep in the earth they
became the River Axe. It broke through fissures in the great
blocks of limestone, swirled around huge beds of the conglomerate,
and worked away to enlarge the caverns, always seeking new
shafts and tunnels down into the earth and eventually back
into the sunlight and the distant sea.
And all the time the dissolved
limestone in the water was itself reforming, creating dripping
stalactites, building up great stalagmites, and turning into
curtains and waterfalls of shining crystalline stone.
The pale limestone and
brownish-red conglomerate is stained vermilion with iron oxide,
black with manganese, grey from the lead once mined on the
Mendip Hills above; here and there is a golden splash of ochre.
Chamber 3, known as The Witch's
Parlour, is a very broad cave with a low ceiling, carved out
by the swirl of the underground river over a million years.
It is now a base for the cave divers.
