Geochemistry of Kokchetav Gneisses and Their Importance for Understanding Strategic Metal Deposits
Abstract
The Kokchetav metamorphic complex is internationally recognized for its voluminous rocks containing metamorphic diamonds and some of the best evidence of ultrahigh-pressure (UHP) metamorphism in the world. It has become a natural laboratory for studying processes in subduction and collision zones.
This lecture will explore how UHP gneisses from the Kokchetav complex experienced partial melting during deep subduction, resulting in depletion of key elements such as light rare earth elements (LREE), thorium (Th), and uranium (U). The extraction of these melts leads to their complementary enrichment and suggests that such melts may play a vital role in the formation of magmatic complexes hosting strategic metal deposits in collisional belts.
About the Speaker
Professor Aleksandr Stepanov received his Bachelor’s and Master’s degrees from Novosibirsk State University in 2002 and 2004, and his Ph.D. in Geology from the Australian National University in 2012. He was a postdoctoral fellow and researcher at the University of Tasmania from 2012 to 2019. Since 2019, he has been a professor at the School of Resources, China University of Geosciences (Wuhan).
Professor Stepanov’s research focuses on:
Mineralogy and deposit geochemistry
In situ micro-analytical techniques (e.g., LA-ICP-MS)
Strategic metal geochemistry and the role of anatexis/metamorphism in metal concentration
Using mineral compositions to reconstruct alteration halos and vector toward mineral deposits
He has published over 40 papers as first author in leading journals including Geology, Journal of Petrology, Chemical Geology, American Mineralogist, Ore Geology Reviews, and Earth Science Reviews.