Diamonds play a unique role in research on Earth’s mantle and its deep carbon cycle. The Alfred P. Sloan Foundation has awarded a grant to launch a new genre of research on diamonds under the auspices of the Deep Carbon Observatory. The goal of the project, Diamonds and the Mantle Geodynamics of Carbon (DMGC), is to create an international research consortium that will become a new international infrastructure for diamond research. Led by Steven Shirey of the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, the proposal involves 20 project leaders and partners from 11 countries, including preeminent diamond researchers.
The purpose of the consortium is to advance studies of natural diamonds and experiments on natural diamond-forming fluids/melts for the understanding of carbon and its mobility in Earth’s mantle. DMGC will seek an understanding of the pathways of carbon exchange between surface and deep Earth, the chemical forms of carbon in mantle fluids/melts, the rates of carbon exchange between the surface and deep mantle, and how the dynamics of Earth's interior controls the deep carbon cycle.
The expected outcomes will be a new understanding of the conditions of diamond formation in the deep mantle, how diamond-forming and diamond-carrying melts interact with Earth’s interior, whether a significant reservoir of mantle carbon is primordial or recycled, and how carbon is transported and stored in the mantle now and over the past 3.5 billion years
the age of the oldest known diamonds. These outcomes may transform our knowledge about the volcanic flux of carbon, the access of the biosphere to deep mantle, and the behavior of carbon in Earth’s interior under extreme conditions.
The Alfred P. Sloan Foundation has awarded a separate grant to create a community data infrastructure for diamond samples and the data generated by their study. The principal investigator is Kerstin Lehnert of the Lamont-Doherty Earth Observatory of Columbia University. The objective of this project is to generate high-quality information resources that will facilitate the sharing of diamond samples and data and that are essential for the research not only within the Diamonds and Mantle Geodynamics of Carbon initiative, but across all DCO Science Directorates.
Figure: A rough diamond from Orapa, Botswana displaying a prominent sulfide inclusion. Credit: Steve Shirey.