Hooray for CaCO3

I'm not ignoring the disaster in Haiti, but there's nothing I can add to what's been said. I haven't been there or anywhere in the Caribbean, but I've seen poor people living in shanties in South America, India, South-East Asia, even Australia, and I can imagine only too well how it is for them, already amongst the world's unluckiest, to have such devastation visited on them. I've donated what I can, and I hope you have too.

Moving on.

Today's post celebrates the pleasure that calcium carbonate gave me last year: specifically in the form of limestone karst. This is because I'm writing a story about The Burren in western Ireland, where the hills look as though they've been spread with silver icing. It's actually a layer of limestone, combed through by deep parallel grooves, that has been exposed by glacial action. In European geological terms, it's young, but the human history there is ancient, with standing stones erected five thousand years ago - that's older than the Pyramids. In spring, the rock bursts with flowers, 650 species, but when I was there in autumn, it was bare, gleaming pewter against the rust of the heather.

It was lovely to see the limestone in its natural form, having already enjoyed it made into the drystone walls that edge the green-as fields; and processed into the building blocks of the many child's-book castles we traipsed over in Wales; gloriously carved on the soaring cathedrals of Gloucester and Lincoln: and, on a domestic scale, made into the beautiful honey-coloured cottages of the Cotswolds.

But it was most spectacular in Thailand, in Phang Nga Bay off Phuket, where the turquoise sea lapped an astonishing sight.

>>> ...Limestone always puts on a good show, but what Phang Nga Bay has over, say, Castle Hill in Canterbury, is the drama of 40-plus water-sculpted islands rising high and sheer out of an opal-coloured sea. Hung with trails of vegetation and undercut by wave action, these craggy karsts seem to teeter precariously; and when our boat moored close to one, we were shown that some are even less solid than they appear.

Transferring into inflatable dinghies, we were rowed beneath the overhang where we found hidden tunnels scoured through the stone by the waves. The tide was high, making the roof so low that we had to lie flat in the boat as it squeezed into the dark, where our torches picked out tiny bats dropping from the ceiling to fly ahead of us. It was like travelling through a funnel: as the roof came down, the sides pressed in so that we had to fit our fingers into the pock-marked rock to pull the dinghy along. The surface felt rough, and just as the thought was forming that sharp edges and inflatable boats are not a happy combination, we heard a sudden hiss. Alarmed shrieks were followed by loud sighs of relief as we realised the air-letting was deliberate so that, slightly slimmer, the boat could slip through the tunnel to the secret lagoon in the centre formed by the collapse of the cave roof.

Called ‘hongs’ or rooms, these doughnut holes are magical places: as we emerged from the dark, a snowy white egret lifted from the gnarled roots of a leggy mangrove growing in the middle and flew up into the circle of blue sky where a sea-eagle was already soaring high above us. Primitive-looking amphibians, mud-hoppers, crept out of the still, quiet water onto the tree roots and it felt like the beginning of the world...

[Pub. Press 13/7/09]