Expedition to South Africa, organized by Harvard University. On the expedition he met Alexander Du Toit, both geologists were among the (at that time rare) supporters of Alfred Wegeners' continental drift theory. Molengraaff was a close friend of W. F. Gisolf, who named his youngest son after him but died in a Japanese concentration camp. Molengraaff retired in 1930. References Sources F. R. van Veen, 2004, Gustaaf Molengraaff, een avontuurlijk geleerde H. A. Brouwer, 1942: Levensbericht van Gustaaf Adolf Frederik Molengraaff in jaarboek der K.N.A.W. 1941–1942 A. J. Pannekoek, 1962: Geological research at the universities of the Netherlands, 1877–1962 in Geologie & Mijnbouw, vol. 41 no. 4 pp. 161–174 External links 19th-century Dutch explorers 19th-century Dutch geologists 20th-century Dutch East Indies people 20th-century Dutch explorers 20th-century Dutch geologists 1860 births 1942 deaths Academic staff of the Delft University of Technology Leiden University alumni Members of the Royal Netherlands Academy of Arts and Sciences People from Nijmegen Academic staff of the University of Amsterdam Utrecht University alumni Wollaston Medal winners Presidents of the Geological Society of South Africa