The Granite Controversy and its Aftermath

Abstract

Opinions about the nature and origin of granite have divided geologists for the greater part of the history of the subject as a recognised branch of the natural sciences. The earliest known controversy in the later part of the eighteenth century revolved around the contrasting views of two schools of thought, the Neptunists and the Plutonists. The Neptunists were represented principally by Abraham Werner of Freiberg 1749-1817, and the Plutonists by James Hutton of Edinburgh 1726-97. The Neptunists believed that granites were a chemical precipitate from a universal ocean whereas the plutonists considered them to be due to the consolidation of matter made fluid by heat. Hutton observed veins of granite which had intruded crystalline metamorphic rocks in the Scottish Highlands, and concluded that they could only have originated by the solidification of molten rock material injected from below. This observation contributed to the eventual resolution of the dispute in the favour of the Plutonists.