James Geikie was the younger brother of Archibald and another important geologist of his day, though not quite as influential as his older brother. He joined the Geological Survey in 1861 as an assistant mapping geologist, working with his brother. He contributed to the mapping of the western part of the Midland Valley, before turning his attention to the Southern Uplands and finally the Grampian region.
Geikie was mostly recognised for his contribution to the advancement of glaciation, and was described as one of “the most eminent glacialists of his day”. During his mapping activities of drift deposits, he found evidence of warmer, inter-glacial periods. He suggested that the existence of river terraces at different levels might indicate climatic cycles during the Pleistocene, as opposed to Agassiz’s theory of a single great Ice Age.
He became the District Surveyor for Scotland in 1869, before succeeding his brother as Murchison Professor of Geology at Edinburgh University in 1882. Like his brother, he was also a writer, publishing several books throughout his career, perhaps most notably ‘The Great Ice Age and its Relation to the Antiquity of Man’, his first book in 1874.
Flett, Sir John Smith. 1937. The First Hundred Years of the Geological Survey of Great Britain. His Majesty’s Stationery Office, London.