It has taken millions of millennia for the Irish landscape to evolve - and the result is unique in its diversity, writes Eileen Battersby
Between 50 and 60 million years ago, highly volatile lavas poured from rifts in the earth's crust. In the absence of major volcanic activity, these lava rivers poured across the surface. This flood basalt created what we now know as the high plateau scenery of counties Antrim and Derry. Now about 900 metres thick, or half of its original density, its early stages of development produced a vast lake of molten lava. As the lava slowly cooled and froze it contracted and cracked, and created a solid honeycomb of solid rock. At a distance it resembles a bizarre organ worthy of a great cathedral. This collection of hexagonal pipes is a great natural wonder, known as the Giant's Causeway.
Myth tells us why it was built, to facilitate an angry giant in his settling of a dispute. It's a good story, but the reality is part of Ireland's geological evolution. Fittingly the first World Heritage Site on the island of Ireland was created by nature, not man.
On a far more vast scale is the Grand Canyon of the US, another of the natural wonders of the world and also a World Heritage site, a status which should be sought for the Burren.
Slow and relentless, etched out over millions of years, geology is the story of earth movements and it is the shaper of landscapes. Because of its awesome time scale, it is a story that is almost impossible to comprehend and it is equally impossible to avoid, because it determines the very ground we walk on.
Ireland's geology is unique in its diversity. For a small island situated to the north west of the European mainland, its geological range is impressive and has created a dramatic landscape; moving clockwise it includes the granite mountain spine of Co Wicklow, the old red sandstone of much of Munster, the limestone escarpment of the Burren and the Aran Islands, the quartzite of Connemara and the ancient rock base of the Nephin range, the ancient rock base of Errigal in Co Donegal and by contrast, the younger basalt lavas of the north east and the Antrim plateau.
It was Ireland that gave the word Eiscir or Esker to the language of geology. The esker is one of the most distinctly Irish of landforms. These long, steep-sided ridges are the stranded beds of what were Ice Age rivers that flowed beneath glaciers.
When the ice melted, the rivers' beds became ridges. Today their legacy remains in the midlands. The great Esker Riada which ran east-west across the middle of Ireland, meeting the Shannon at Clonmacnoise, created a natural routeway. Eskers served not only as roads but provided early farmers with useful tracts of easily drained, easily worked land. Another specially Irish feature of our geology is the drumlin, the small aligned oval mounds of glacial material that stretch in a wide belt across north central Ireland, from counties Down to Mayo, and are most frequently associated with counties Cavan and Monaghan, creating the famous basket- of-eggs topography.
The study of Ireland began in earnest through the multidisciplinary approach of gentleman scholars in the late 18th century. These were the pioneering antiquarians, enlightened individuals with an interest in the past. They looked to the archaeological remains, the beautiful ruins of monasteries and castles that dominated the landscape. But they also studied the plants and the minerals.
Rock collecting became a popular pursuit, largely due to a growing fascination with fossils. Links were made with evidence of the animal life of the past encased in the rock and mineral that remained. Slowly by slowly, and in some cases rather quickly, this interest in the physical and the natural became a science. Field studies became more than a pleasant way of passing an afternoon, they were deliberate investigations in pursuit of research and answers. Discoveries created records and it all ran parallel with Darwinism.
By the 1850s Thomas Oldham, Professor of Geology at Trinity College 1845-1850, and a member of the Geological Survey, had discovered slates at Bray Head in Co Wicklow, which contained fan-like fossil impressions of a small alga dating back 550 million years.
Just as today any serious archaeological survey incorporates recording of the site's geological profile, the antiquarians of the past were alert to the geology. Any examination of any site begins with its landscape and the structure upon which that landscape is based - its geology. The immense timescales make it complex and at times overwhelming. But anyone with an interest in understanding the Irish landscape, its diversity and variations, should begin by approaching the geology. It need not be as intimidating as it sounds.
One of the Ireland's finest and most daring scholars, the late Frank Mitchell (1912-1998), author of the classic Reading the Irish Landscape (1986, 1990, 1997; Dublin), decided to make it a bit easier for the rest of us to grasp the natural phenomenon that is the science of geology. In an extraordinary 1994 essay, Where Has Ireland Come From (Country House), Mitchell the polymath took a group of fellow naturalists on a whistle-stop 1700 million year geological tour of Ireland.
Delivered in the form of a conversational monologue, Mitchell, conducted this tour while aboard an imaginary magic carpet. He and his fellow travellers were privy to the Irish landscape as it underwent change through the formation of mountains, the emergence of life-forms, the birth of the Atlantic Ocean, the onslaught of the Ice Age and with it the disappearance of the woodlands that duly returned with the retreat of the ice.
It is a dramatic odyssey divided into three parts, from 1700 million to two million years ago, from two million to 10,500 years ago, from 10,500 to the present day. It was also a ground-breaking thesis, including as it does the beginnings of human settlement and archaeology, and is far more deliberate than its fanciful construct might lead one to suspect.
Mitchell was an original, a multidisciplinary scholar and visionary but he was also the product of a great tradition extending back to Robert Lloyd Praeger (1865-1953), whom he knew, and further beyond to a 19th century Irish world of scholarship that had itself been shaped by earlier generations of visionaries.
Mining methods brought with them the development of geology as a science in Europe from the early 18th century onwards.
The Dublin Philosophical Society 1683-1708 facilitated the first Irish geological investigations. William Molyneux, its founder was a remarkable individual and its was his brother Thomas who lead early research on the Giant's Causeway and also, the Giant Irish Deer. Patrick Wyse Jackson traces the history of Irish geology in his essay "Fluctuations in Fortune: Three Hundred Years of Irish Geology" (Nature in Ireland, Lilliput; 1997), in which he refers to the short-lived Physico-Historical Society. That society inaugurated the first formal geological survey of Ireland, although only four counties were recorded.
Such studies were then undertaken by the Royal Irish Academy. Major figures in Irish geology began to emerge such as an Academy president, Richard Kirwan, the author of Elements of Mineralogy and a giant in Irish science.
Richard Griffith, who surveyed and mapped the Leinster Coalfields and others, was to compile an "unofficial" geological map of the country. Meanwhile, the Geological Survey of Ireland gained much momentum through the Ordnance Survey and from about 1820 onwards, some 60 years of research began. Although geology had been taught at Trinity College from the 1770s, with specimens collected from 1777, the chair was finally established in 1843.
From about 1890 a decline began which continued until the 1960s. During that period, geology had not so much been forgotten as overshadowed. People like Mitchell reinvigorated the study. In 1981 Charles Hepworth Holland published his definitive A Geology of Ireland, revising it further in 2001 as The Geology of Ireland. Recently, he has published The Irish Landscape: A Scenery to Celebrate. It takes a more relaxed approach to the subject and follows a whistle-stop format moving clockwise around the country. As with Mitchell's work, it suggests the wonders of geology may be presented in a user-friendly form.
Science, natural beauty and the wonder of the millions of years that create a time that defies humankind certainly meet in the spectacle that is geology.
• The Irish Landscape: A Scenery to Celebrate by Charles Hepworth Holland is published by Dunedin Academic Press (£18.99 sterling)