Johann Carl Vogel (7 September 1932-30 January 2012)
At the beginning of 2012, the Quaternary community lost one of their most gifted scientists who had contributed to both geochronology and the study of stable isotopes. John Vogel was born in Pretoria and studied at the University of Pretoria, first obtaining a BSc and then an MSc in chemistry in 1955. He then moved to the University of Heidelberg, Germany, where he constructed a mass spectrometer for measuring the isotopes of carbon and oxygen. He obtained his doctorate in 1959 with a thesis on the determination of fractionation factors of the carbon isotopes. During this time he became interested in the newly developing method of radiocarbon dating, and was immediately aware of its potential ability to solve problems in archaeology and environmental studies. He collaborated with KO Münnich to apply radiocarbon to the dating of groundwater and carbonate deposits. They indicated the increase of 14C in the atmosphere due to nuclear weapon testing in the 1950s and followed its effect into local vegetation. Radiocarbon in groundwater was found to be useful in both arid and humid environments. Recognition of the fact that 14C in groundwater is diluted by dead carbonate from the soils, dates from this period.