We were pleased to be able to host the annual Lobanov-Rostovsky Lecture in Planetary Geology this week. Inaugurated in 2013 in recognition of the support given by alumnus Mr Nikita Lobanov-Rostovsky (BA Geology, Christ Church 1955) to the Department through the endowment of the Lobanov-Rostovsky Associate Professor in Earth Sciences, this annual public lecture examines the fundamental questions of the origin of planets, formation and deformation and geology on a global scale. Mr Nikita Lobanov-Rostovsky and his wife June were able to attend and we were pleased to be able to hold the lecture once again after a long break due to Covid.
Each year we have the most prominent scientists examine the fundamental questions of the origin of planets, formation and deformation and geology on a global scale and Lindy Elkins-Tanton, Alessandro Morbidelli, Raymond Pierrehumbert, John Grotzinger and Alex Halliday have all been past speakers. This year Professor Bernie Wood, University of Oxford, spoke on his lifelong research on the Geochemical evidence for how the Earth accreted and differentiated. Bernie’s research is in experimental petrology, aimed at experimentally simulating conditions within the Earth in order to understand fundamental petrological and geochemical processes.
The principal evidence for the earliest history of the Earth comes from the chemical and isotopic compositions of the silicate mantle and crust, collectively called the “Bulk Silicate Earth” (BSE). BSE is depleted in siderophile (iron-loving) elements such as Ni, Co, Au and Pt relative to undifferentiated meteorites because these elements were partitioned into the core. How they partitioned provides a wealth of information about the state of the early Earth. There are also isotopic differences between silicate Earth and meteorites which can be used to constrain the timescales of accretion, the timing of the moon-forming impact and the changing composition of the Earth as it grew from smaller bodies. In this talk Bernie drew together these disparate data into a coherent view of the first 150 M.yr of Earth history.