History
Some 50 to 60 million years ago, during the Paleogene period, Antrim was subject to intense volcanic activity, when highly fluid molten basalt intruded through chalk beds to form an extensive lava plateau. As the lava cooled rapidly, contraction occurred. Horizontal contraction fractured in a similar way to drying mud, with the cracks propagating down as the mass cooled, leaving pillarlike structures, which are also fractured horizontally into "biscuits". In many cases the horizontal fracture has resulted in a bottom face that is convex while the upper face of the lower segment is concave, producing what are called "ball and socket" joints. The size of the columns is primarily determined by the speed at which lava from a volcanic eruption cools. The extensive fracture network produced the distinctive columns seen today. The basalts were originally part of a great volcanic plateau called the Thulean Plateau which formed during the Paleogene period.
Read more about this topic: Giant's Causeway
Famous quotes containing the word history:
“History has neither the venerableness of antiquity, nor the freshness of the modern. It does as if it would go to the beginning of things, which natural history might with reason assume to do; but consider the Universal History, and then tell us,—when did burdock and plantain sprout first?”
—Henry David Thoreau (1817–1862)
“To a surprising extent the war-lords in shining armour, the apostles of the martial virtues, tend not to die fighting when the time comes. History is full of ignominious getaways by the great and famous.”
—George Orwell (1903–1950)
“Every generation rewrites the past. In easy times history is more or less of an ornamental art, but in times of danger we are driven to the written record by a pressing need to find answers to the riddles of today.... In times of change and danger when there is a quicksand of fear under men’s reasoning, a sense of continuity with generations gone before can stretch like a lifeline across the scary present and get us past that idiot delusion of the exceptional Now that blocks good thinking.”
—John Dos Passos (1896–1970)