Igor Tolstikhin, Russian Academy of Sciences
Recipient of the 2013 Urey Award
My life and professional carrier were highly influenced by several people and it is worth presenting them. These are first of all my parents, Nestor and Matil’da Tolstikhin: thanks to their activity, I grew up in a very “earth science environment”. Professor Erik Gerling, who is amongst the top experts in cosmo-geochemistry, introduced me to the importance of isotope science. By the choice of Destiny (I thank her for this!), I met Jan Kramers and we friendly worked together for about two decades; several papers and the book “The evolution of matter” (2008) are a direct result of our collaboration. During 2.5 years, Keith O’Nions was my teacher at Cambridge and Oxford. In the 21st century, my most visited place in the world became the Max Plank Institute of Chemistry at Mainz, with Al Hofmann being my friend, my colleague, and my hospitable host.
These and many other contacts with Russian, European and American scientists developed my research activity which now includes noble gas mass-spectrometry, isotope cosmo-geochemistry, isotope hydrology, modelling of the Earth’s chemical evolution.
I’ve always tried to understand “How does Nature work?” using isotopic compositions of the elements in natural materials. Some answers to this question were obtained thanks to the discovery of solar helium in the deep earth interior (1969). Other important early helium-related results were: the first proposal to use tritium-helium-3 systematic for dating of terrestrial waters (1969); the precise measurement of helium isotope composition in the atmosphere (the only isotopic constant done in Russia, 1970); the Earth degassing models taking into account presence of solar noble gases in the mantle (1975); using the C/3He ratio to study fluxes of major volatile species, e.g. carbon (1976); the model of helium dissipation from the Earth’s atmosphere envisaging fluxes of solar-like mantle helium (1981).
Simultaneously I’ve been studying sources, sites and mobility of noble gas isotopes in rocks and minerals of different origin, age and composition, as well as helium residence times and fluxes within rock (mineral) – pore water – movable ground water system (1976 – 2011).
In middle of the 1970s, chemical transport models of the earth fractionation, degassing and core segregation attracted my and Irma Azbel’s attention (1975 – 1993) and later on I continued these studies with other colleagues; this resulted in the chemical Earth model with whole-mantle convection (2005 – 2008).