Precambrian ice age, at the NATO conference in January 1963, it was not well received; attention was drawn by others to widespread evidence of aqueous deposition. It was not until the 1990s that the idea was more generally accepted, when Paul F. Hoffman and colleagues, argued that several such "Snowball Earth" episodes had occurred towards the end of Precambrian history. Collision Zones Harland investigated mountain belts and the relationship between stresses in the Earth and the building of the mountains. His field work and research in Svalbard looked closely at the Hecla Hoek rocks, a great geosyncline and part of the complex sedimentation belts of Europe, Greenland, and America. The main phase of the Caledonian orogeny in Svalbard deformed this geosyncline in intense fashion, followed by further phases of mountain building. He had ideas on deformation and flow of matter, and developed the concept of tectonic regimes to specify the symmetry and orientation of bulk deformation for use in tectonic analysis. He coined the word ′transpression′ to convey the idea that many mountains have resulted from oblique convergence of the margins of the belt, rather than simple, vice-like compression perpendicular to the length of the belt. He also showed that continued transpression or compression could result in extrusion of the core of the belt, parallel to its length. "Transtension", with pull apart basins in zones of oblique extension, was a natural compliment. Iapetus Ocean Named In 1972 he named the Iapetus Ocean, when writing about the closure of this ocean area, to avoid confusion with the Proto-Atlantic Ocean. The ancient ocean Iapetus, existed before Devonian times, between 600 and 400 million years ago, and its closure caused the deformation of bordering geosynclines and the formation of the Arctic Caledonides. It had been known as the Proto-Atlantic Ocean, but that name implied the initial stages of the current Atlantic Ocean which began opening up some 200 million years later. The term is derived from Greek mythology where Iapetus is the brother of Okeanus and Tethys and father of Atlas from whose name the word Atlantis is derived. Stratigraphy and Time Scales Harland was a leading figure in compiling information on geological time scales and their ongoing development. He saw there was an urgent need to produce reliable time scales and provide organised high quality data for the scientific community. He produced four editions of the geologic time scale starting with the