Bemmelen, Reinout Willem Van

Born Apr. 14, 1904, in Jakarta. Dutch geologist.

Bemmelen graduated from the Technical University in Delft in 1927. From 1928 to 1943 he served as a geologist in government service in the former Dutch East Indies. He is a professor of geology at the University of Utrecht. On the basis of data gathered through many years of research in the islands of Southeast Asia and the mountainous regions of Europe, Bemmelen advanced a number of original ideas in the field of volcanology and tectonics. In 1933 he began to work out a geotectonic hypothesis which he called the unda-tion hypothesis, according to which subsidences (geo-synclines) occur in the earth’s crust as the result of the cooling of subcrustal masses; subsequently, in the process of differentiation of the earth’s mantle, elevations occur within the subsidences, which move outward like waves. At first Bemmelen, having examined geological processes to a depth of 50 km, supported the theory of fixity (the unchanging positions of the continents in relation to each other). He accepted the idea that oceans might be formed as the result of the basification of the continental crust. According to Bemmelen, folds and other deformations in the earth’s crust (including the displacement of entire continents) are due to the flowing together of layers of rock of various thicknesses under the influence of gravity, with tectonic elevation occurring in the depressions. From 1950 to 1960 he put forward the theory of chain reactions embracing all matter on the planet down to its very core. Bemmelen has become a supporter of the theory of continental drift, and he endeavors to combine the fixist and mobilist positions.