LOUGH Doonin Co Kerry is, a small, unassuming and secluded body of water that lies in a deep hollow in the Dingle Mountains near the Connor Pass. One hundred and fifty years or so ago, it became an object of great geological interest when its characteristics and those of its surroundings were cited as coercive, if not conclusive, proof that many thousands of years since Ireland lay under a massive sheet of ice.
Early 19th century geologists were well aware that there existed all over Europe gigantic boulders which differed in composition from their surroundings, and which had obviously been transported to their current location from some distant spot. The accepted explanation for these erratics, as they were called, was that they had been carried by the great currents of water and mud associated with the Biblical Flood. By the early 1800s, however, some scientists had begun to question this explanation: was a great deluge, they wondered - even a divinely inspired one - actually capable of transporting gigantic boulders over such great distances?
Then in 1837 a young Swiss geologist called Louis Agazziz outlined his astounding theory that most of Europe was at one time covered by a thick layer of ice, whose motion had gouged deep grooves in the underlying terrain; it had also swallowed up large chunks of rock in its path, and deposited them in splendid isolation many miles from their point of origin. Agazziz visited Ireland in 1840 and identified several landscapes in Cavan, Down and Dublin that illustrated his theory, but to most pundits of the day the existence of an "Ice Age", Irish or otherwise, was, at best, an open question. The argument was clinched, however, by evidence from Lough Doon presented to the Geological Society of Dublin by one John Ball in November, 1849.
Ball was born in Dublin in 1818, graduated from Cambridge University, and spent several years travelling Europe studying natural history. There he saw the glaciers of Switzerland and became familiar with the controversial theories of Agazziz. In 1846 he returned to Ireland, became a Poor Law Commissioner, and was posted to Co Kerry to assist with measures for famine relief.
Everywhere Ball looked in Co Kerry, he saw signs of ancient glacial activity that were similar to those of more recent origin in Switzerland. Lough Doon and its surroundings, in particular, provided some of the more spectacular examples, and his presentation on them to the GSD, entitled "Notice of the Former Existence of Small Glaciers in the County of Kerry" brought the Ice Age irrefutably to Ireland.