Murchison, Roderick (Impey) (1792-1871)

Scottish geologist responsible for naming the Silurian period (in his book The Silurian System 1839). Expeditions to Russia 1840-45 led him to define another worldwide system, the Permian, named after the strata of the Perm region. Murchison was born in Ross-shire. He entered the army at 15 and fought in the Peninsular War. Often accompanied by geologists Adam Sedgwick or Charles Lyell, Murchison made field explorations in Scotland, France, and the Alps. In 1855 he became director-general of the UK Geological Survey. An ardent imperialist, for many years he was also president of the Royal Geographical Society, encouraging African exploration and annexation. Murchison believed in a universal order of the deposition of strata, indicated by fossils rather than solely by lithological features. Fossils showed a clear progression in complexity. The Silurian system contained, in his view, remains of the earliest life forms. He based it on studies of slate rocks in South Wales. With Sedgwick's cooperation, Murchison also established the Devonian system in SW England.