Reference number : GC-2017-Q1-03021, amendment number : , agreement type : G, recipient legal name : Stachel, Thomas (University of Alberta), recipient country : CA, recipient province : nan, recipient city : Alberta, recipient postal code : nan, program name english : Discovery Grants Program - Individual, program name french : Programme de subventions à la découverte - individuelles, program purpose english : Diamond exploration and mining is the principal economic driving force in Canada&rsquo;s remote North. However, current levels of production will be unsustainable unless new deposits are discovered within the next few years. To help develop more efficient exploration strategies, we will geochemically fingerprint the conditions deep in the Earth&rsquo;s mantle that enhanced or prevented diamond formation in the distant past.
 
 
The investigations outlined below are expected to produce not only ground-breaking basic research but also new and better methods for diamond exploration.
 
 
 1. Processes of diamond formation
 
The layered internal structure of diamond can be compared to tree rings in that both can reveal complex and extended growth histories. I direct a multi-collector ion microprobe facility, which will enable us to obtain profiles of carbon and nitrogen isotopic compositions and nitrogen contents at high spatial resolution across diamond growth zones. These profiles allow us to deduce the chemical character of the original diamond-forming fluids or melts and reveal if they were methane- or carbonate-bearing. By studying diamonds with known ages of crystallization, we will be able to follow variations in the preferred modes of diamond precipitation through time.
 
 
 2. Unconventional diamond deposits
 
Archean cratons are large, stable blocks of the Earth&rsquo;s crust that are older than 2.5 billion years. The lithospheric mantle beneath such cratons is the source of &gt;99% of current diamond production, and the rock type harzburgite is its key diamond substrate. However, younger areas of the crust can also host world-class diamond deposits. The rock type eclogite is a key diamond substrate in such unconventional deposits, but our preliminary results suggest that lherzolite may also be important. We will investigate two such diamond-bearing areas beneath the Canadian Shield (sampled by kimberlite volcanoes at Fort &agrave; la Corne and the Victor Mine) that were strongly affected by tectonic/thermal events less than two billion years ago. By studying the diamonds, their inclusions, and the associated mantle rocks, we aim to determine the diamond-forming conditions in the lithospheric mantles of these areas through time.
 
 
 3. New Canadian diamond deposits
 
Diamonds from two new deposits will be used to probe the mantle roots of little-studied deep sections of the Canadian Shield:
 
(1) The Chidliak kimberlite field (Baffin Island). This area is underlain by a small cratonic fragment of unclear origin, and its diamond source rocks have not yet been investigated.
 
(2) The Gahcho Kue diamond mine. This mine provides unique access to an exceptionally thick section of lithospheric mantle in the southern Slave Craton.
 
 
The knowledge gained in all three study themes will be crucial to future exploration for new diamond deposits in Canada., program purpose french : Diamond exploration and mining is the principal economic driving force in Canada&rsquo;s remote North. However, current levels of production will be unsustainable unless new deposits are discovered within the next few years. To help develop more efficient exploration strategies, we will geochemically fingerprint the conditions deep in the Earth&rsquo;s mantle that enhanced or prevented diamond formation in the distant past.
 
 
The investigations outlined below are expected to produce not only ground-breaking basic research but also new and better methods for diamond exploration.
 
 
 1. Processes of diamond formation
 
The layered internal structure of diamond can be compared to tree rings in that both can reveal complex and extended growth histories. I direct a multi-collector ion microprobe facility, which will enable us to obtain profiles of carbon and nitrogen isotopic compositions and nitrogen contents at high spatial resolution across diamond growth zones. These profiles allow us to deduce the chemical character of the original diamond-forming fluids or melts and reveal if they were methane- or carbonate-bearing. By studying diamonds with known ages of crystallization, we will be able to follow variations in the preferred modes of diamond precipitation through time.
 
 
 2. Unconventional diamond deposits
 
Archean cratons are large, stable blocks of the Earth&rsquo;s crust that are older than 2.5 billion years. The lithospheric mantle beneath such cratons is the source of &gt;99% of current diamond production, and the rock type harzburgite is its key diamond substrate. However, younger areas of the crust can also host world-class diamond deposits. The rock type eclogite is a key diamond substrate in such unconventional deposits, but our preliminary results suggest that lherzolite may also be important. We will investigate two such diamond-bearing areas beneath the Canadian Shield (sampled by kimberlite volcanoes at Fort &agrave; la Corne and the Victor Mine) that were strongly affected by tectonic/thermal events less than two billion years ago. By studying the diamonds, their inclusions, and the associated mantle rocks, we aim to determine the diamond-forming conditions in the lithospheric mantles of these areas through time.
 
 
 3. New Canadian diamond deposits
 
Diamonds from two new deposits will be used to probe the mantle roots of little-studied deep sections of the Canadian Shield:
 
(1) The Chidliak kimberlite field (Baffin Island). This area is underlain by a small cratonic fragment of unclear origin, and its diamond source rocks have not yet been investigated.
 
(2) The Gahcho Kue diamond mine. This mine provides unique access to an exceptionally thick section of lithospheric mantle in the southern Slave Craton.
 
 
The knowledge gained in all three study themes will be crucial to future exploration for new diamond deposits in Canada., agreement title english : Diamond formation in Earth’s mantle, agreement title french : Diamond formation in Earth’s mantle, agreement number : RGPIN, agreement value : 235000.0, agreement start date : 2017-05-10, agreement end date : nan, description english : nan, description french : nan, expected results english : nan, expected results french : nan, additional information english : Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023), additional information french : Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2022-2023), owner organization : nserc-crsng, owner organization title : Natural Sciences and Engineering Research Council of Canada | Conseil de recherches en sciences naturelles et en génie du Canada