DIRT Talk: Yana Fedortchouk - How Diamond Dissolution Experiments Can Help Exploration
Yana Fedortchouk
Professor and Graduate Coordinator
Department of Earth and Environmental Sciences Dalhousie University
Title: How diamond dissolution experiments can help exploration
Abstract: Kimberlites are the deepest magmas that reach the surface of the Earth and the hosts to the largest diamond mines in the world. They bring loads of mantle material containing diamonds from deep mantle to the Earth’s surface. Diamond mining is an important industry for Canada, the third largest producer of diamonds in the world. However, the factors governing diamond mineralization remain inadequately understood, posing significant challenges for the diamond exploration industry. Decades of intensive research have revealed that diamonds can originate throughout the mantle, from the lower mantle to the lithospheric mantle, as indicated by mineral inclusions within diamonds. Carbon and nitrogen isotopes further suggest diverse carbon sources, including subducted crustal and deep mantle materials. Inclusions of mantle silicates in diamonds or diamond-bearing mantle xenoliths provide crucial insights into the geological processes influencing diamond growth, preservation, or destruction in the mantle. However, uncertainties surrounding the syngenesis of diamonds and these mantle silicates complicate the determination of diamond formation conditions. The simplicity of diamond's chemical composition, primarily consisting of carbon, limits its utility in determining diamond formation conditions. However, the intricate and diverse surface textures of diamonds retain a record of various geological events throughout their history. This presentation will explore these features, their associations with specific kimberlite types, and demonstrate how experimental petrology can leverage diamond surface characteristics to unveil the intricate and lengthy history of natural diamonds. We will discuss how laboratory experiments can help addressing key questions vital for advancing diamond exploration and unravel the nature of mantle metasomatism by deep fluids and melts, elucidate the speed at which kimberlite magmas transport diamonds to the surface, and assess the aggressiveness of kimberlite magma towards diamonds. Join us as we delve into the complexities of diamond history, utilizing high-pressure-temperature experiments to shed light on the enigmatic world of kimberlites and diamonds.
Bio: Yana Fedortchouk graduated from Moscow State University (Moscow, Russia). She spent several summers during her high-school and undergraduate studies working as a geological field-assistant in various polymetallic deposits of Tian Shan Mountains in Uzbekistan and Tajikistan. However, summer course at Institute of Experimental Mineralogy switched her interests to experimental petrology. Yana started graduate studies at Vernadsky Institute of Geochemistry, Russian Academy of Science, using experiments to address the origin of carbonatites, interrupted by a move to Canada. Yana continued with her passion for experimental petrology first working as a Research Assistant and then doing PhD under supervision of Prof. Dante Canil at University of Victoria, BC. Yana’s PhD was focused on understanding crystallization conditions of kimberlites and their effect on diamond preservation. During her PhD, she did contract work for BHP Billiton Diamonds Inc studying diamonds from the first Canadian diamond mine - Ekati. Yana was very lucky to work under the guidance of Prof. John Gurney (University of Cape Town), who was collaborating with BHP Billiton Diamonds. Work with Ekati diamonds switched the main focus of Yana’s PhD to understanding diamond resorption in kimberlites, which still remains her main research interest. After finishing PhD, Yana spent one year as a project geologist for Yukon Geological Survey investigating primary sources of placer platinum and possible diamond occurrences in Yukon. In 2007 she moved to Halifax to take a position at the Department of Earth Sciences, Dalhousie University, and in 2008 opened Experimental Petrology lab in the Department. Yana continues active collaboration with diamond industry especially with De Beers, as well as collaboration with Geological Survey of the Northwest Territories, the home to the main Canadian diamond mines. She likes developing projects for her students, which bring together industry and government expertise and resources to address fundamental geological questions combined with practical applications.
Time
Location
Milligan Room, 8th Floor Biology-Earth Sciences Wing, Life Sciences Centre, Dalhousie University