Pleistocene glaciation had extended in Northern Europe as far south as Berlin and London, and covered an area of two million square miles. North American Pleistocene glaciation had extended as far south as Cincinnati, Ohio for an area of four million square miles. The present Greenland glacier covers one million square miles and the Antarctic glacier, some five million.

Coleman concluded that the Pleistocene had covered a fifth of the total land surface of the earth and that half of this glaciation, Greenland and Antarctica, is still with us.

The geologist travelled the world in search of Pre-Pleistocene glaciers. In 1905, he visited South Africa and studied the Dwyka Permo-Carboniferous formations of glacial rocks in Natal, Transvaal, and Cape Colony.

In his glaciation quest, Coleman also visited such countries as India, Australia, Brazil, Argentina, Scandinavia, Canada, Bolivia, New Zealand and Uruguay. Coleman collected specimen of all the early glacial materials he encountered and many geologists sent and gave him representative samples from their finds. Coleman presented these samples to the Royal Ontario Museum, and they make up one of the leading collections of glacial materials in the world.

On his retirement in 1922, at the age of seventy, mountains and glaciers became Coleman's most important interest. In 1926, he completed his