Early ideas about erratic boulders and glacial phenomena in The Netherlands

Abstract

AbstractThe development of ideas about the origin of erratic boulders in the northern Netherlands is reviewed for the period from 1770 to 1907. A Scandinavian origin of these rocks was recognized at an early stage, but the transport mechanism was not understood. Initially, the Biblical Flood was proposed as a geological agent by Horace de Saussure (1740–1799) in 1780. Charles Lyell (1797–1875) developed a theory of climate change and a ‘glacial drift theory’ to account for the movement of large boulders in the Alps, and he introduced the term ‘drift’ in 1840. Several prize contests of the two Dutch Scientific Societies, the Hollandsche Maatschappij der Wetenschappen and the Teyler Genootschap, both at Haarlem, concerned erratics. The competitions of 1827 and 1828 were won by Johann Hausmann (1782–1849) from Göttingen University and Reinhard Bernhardi (1797–1849) from the Forstakademie Hitzacker, respectively. Hausmann assumed that a great freshwater flood, caused by the breakthrough of natural dams in the Scandinavian mountains, swept boulders to the plains of the northern Netherlands. Bernhardi vaguely suggested the possibility of transport by glaciers. The prize for the third contest (1861) was awarded in 1868 to the Swedish geologist Otto Torell (1828–1900). He invoked the land-ice theory, which, as regards The Netherlands, proposed that the boulders had been transported by glaciers descending from the Bothnian Gulf and extending into the northern Netherlands, amongst other areas. However, for reasons unknown, Torell's manuscript was never printed, and he never collected his gold medal and the prize money. At a historic meeting of the Deutsche Geologische Gesellschaft at Berlin in 1875, 7 years after winning the Haarlem contest, Torell managed to convince his audience of the land-ice theory after showing striated rock surfaces at a well-known outcrop at Rüdersdorf near Berlin. Thus, it took about a century from the first speculations in the late eighteenth century about the origin and transport of erratic rocks to about 1880 before the land-ice theory became generally accepted in continental NW Europe.