To live in small-farm Connacht is to feel a lot closer to the Stone Age: there's so much of the stuff about in its original, uncompromising form, not yet mashed and buffed into urban concrete geometries. Here there's still the knowledge (just about) of how to crack a sunken boulder with a turf fire and cold water, and the skill of fitting rocks together in a dry-stone wall.
Drilling rawlplug-holes for more bookshelves in the livingroom last week, I cursed as the bit kept meeting impossibly hard pebbles - souvenirs of yesterday's back-yard block-making that used natural gravel from an esker or seashore. Things have changed: today's building blocks, made from crushed limestone, reach the furthest ends of boreens on a lorry with a crane.
In a recent issue of the Indus- trial Minerals Newsletter put out by the Geological Survey of Ireland, a Roadstone man, John Holmes, gave startling figures for the amount of rock needed to build one stand-alone bungalow. From the fill for the driveway and subfloor to the 2,000 concrete tiles on the roof, it comes to between 300 and 400 tonnes of aggregate. This is not some mysterious product builders use, but the rock, sand and gravel of this island, suitably crushed and riddled and washed, and processed in different forms.
Multiply that 400 tonnes by the 37,000 houses built in Ireland last year and add in the rest of the construction industry - roads and factories and so on - and the consumption of rock approaches 50 million tonnes annually. About 35 million tonnes of this come from hard rock quarries, extracted by drilling and blasting, and the rest is sand and gravel dug out from glacial deposits.
To put this in perspective, one cubic kilometre of mountain would produce, perhaps, 2.6 billion tonnes of aggregate or about 50 years' worth at the present Irish rate of use. Carving up whole mountains has, indeed, been talked of in plans for hard-rock "superquarries" alongside deepwater jetties on the west coast of Scotland (much to the horror of Friends of the Earth and the local B & Bs).
In the Republic, however, production is shared out between more than 200 quarries and pits - limestone from the great raft of rock beneath the Central Plain; hard rock (granite, sandstone, dolerite and the rest) from quarries in the island's mountain rim; sand and gravel from drumlins and eskers in the midlands and east. But the key fact about aggregates is their cheapness. They sell at a few pounds per ton, if the journey to the customer is more than about 25 kilometres, extraction becomes uneconomic.
So, in a construction boom of the kind now overtaking Ireland, the pressure for new, extended or reopened quarries is intensifying. Everywhere, the ramparts of wider, straighter roads are heaping rocks across the landscape; small towns will double in size and ribbon out along the highways; new factories are arriving in green fields.
The amount of land in quarries is spreading by about 100 acres a year, which might seem a trifling amount. But it depends, of course, where they are and who is living around them. The extraction of bulk minerals needs only planning permission, not a mining licence, but this is proving increasingly hard to get. Even with the industry's new environmental codes, fears of dust, noise, vibration and heavy traffic are hard to assuage.
THE huge appetite for sand and gravel can create particular problems. In the long term, some of it may be scooped from the sea-bed. Mapping of resources along the Cork and Waterford coasts is going on already, and this, in turn, will pose new headaches for coastal protection. Inland, meanwhile, the handiest source of sand and gravel is often the nearest esker, and this is a real challenge to what we think of as "heritage".
The eskers - long, high ridges of sand and gravel - were deposited by meltwater streams in tunnels beneath the glaciers of the last Ice Age. Near Tullamore in Co Offaly, for example, they wind for more than 30 km across the midland plain.
They are very special landforms from Ireland's quaternary history that gave a new word (from the Irish, eiscir) to world geology. They belong to our human history as well, as highways that took people westwards through the bogs. And the grasses and flowers on steep esker slopes are some of the last semi-natural vegetation on the island.
Eskers have been nibbled into locally for generations, for the lime-rich material that makes such splendid concrete. Machinery has stepped up the devastation. A geologist described to me, with real pain in his voice, seeing an esker which had been excavated right down the middle "as if a worm had eaten it", while leaving the slopes as high walls on either side.
As yet, there is no designation of specific geological heritage sites and so nothing for county council planners to enter on to their maps. This will now change, as the Geological Survey decides what needs protecting and consults with Duchas (the heritage service) on new national heritage areas. Meanwhile, the "worms" will go on gnawing, and many eskers will follow the midland raised bogs into ruin.
Ecologists have to admit that, in the longer term, quarries may be quite good for biodiversity, whatever they do to the view. They create new and specialised niches for plants and aquatic life, and new nesting-places for birds. High ledges in the hard-rock quarries of the east have been important to the revival of the peregrine falcon, and even ravaged eskers have brought sand-martins to nest in holes in their cliffs.
There's even an argument of sorts for "superquarries", in that one vast hole on some remote piece of deep-water coast might be preferable to a dozen new holes inland. The hills around Killary Harbour, for example, have great reserves of greywackes, the kinds of sandstone that give a great non-skid surface to motorways. Don't even think it.