The Sheahan Diamond Literature Reference Compilation is compiled by Patricia Sheahan who publishes on a monthly basis a list of new scientific articles related to diamonds as well as media coverage and corporate announcements called the Sheahan Diamond Literature Service that is distributed as a free pdf to a list of followers. Pat has kindly agreed to allow her work to be made available as an online digital resource at Kaiser Research Online so that a broader community interested in diamonds and related geology can benefit. The SDLRC Blog is a guest commentary by an industry expert about articles, themes and trends in recent issues of the SDLRC.
Comments by Brooke Clements
Brooke Clements received a B.Sc in Geology from Indiana University and an M.Sc in Economic Geology from the University of Arizona. From 1982 to 1997, he was an Exploration Geologist and Regional Manager for Exmin Corporation where he conducted diamond exploration programs throughout the United States. From 1998 to 2007 he was Vice President, Exploration for Ashton Mining of Canada Inc. Under his leadership, the Ashton-SOQUEM exploration team discovered the Renard diamond district in Quebec where Stornoway Diamonds opened the Renard Diamond Mine in 2016. From 2007 to 2015 he was President of Peregrine Diamonds Ltd. where he led the team that discovered the Chidliak diamond district on Baffin Island in the Canadian Arctic. Currently, Brooke is President of JBC Ventures Ltd., a consulting company specializing in mineral exploration and community and government relations. He is also President and CEO of Craton Minerals Ltd., a private diamond exploration company focused on discovering North America's next new diamond district.
Brooke Clements has volunteered to highlight the scientific articles that caught his attention in the monthly reference compilations. The opinions expressed are solely his and he can be reached at .
Goldschmidt Conference: The Goldschmidt Conference 2019 on geochemistry and related subjects was held from August 18-23 in Barcelona. This month Pat references 19 talks from the conference related to diamonds and the mantle and the abstracts are available at the Kaiser Diamond Resource Center. Here is the pdf link to the 2019 Program.
Very good summary of the geology and exploration history of the Massadou kimberlite dyke swarm in Guineau. The dykes have low diamond content and the first one was discovered in 2000 during assessment of alluvial diamond deposits in the area.
A Goldschmidt abstract. Czas completed a dissertation on the Sask craton in 2018 at the U of Alberta. Because of the presence of Archean ages in some crustal material, and significant diamonds in the Fort A La Corne kimberlite field in Saskatchewan, it has been postulated that a small Archean craton, the "Sask Craton", surrounded by the Paleoproterozoic Trans-Hudson orogeny (THO) was present in the area. Mantle xenoliths were studied and the mantle was found to be lherzolitic with Re-depletion ages having a main mode in the Paleoproterozoic. The research is summed up well in the last paragraph of the abstract. "With the absence of Archean ages, the main depletion and stabilisation of the Sask Craton occurred in the Palaeoproterozoic, closely associated with the Wilson cycle of the THO. From a diamond exploration perspective this indicates that major diamond deposits can be found on cratons that were stabilised in the Palaeoproterozoic."
Accurately determining kimberlite-country rock contacts is very important in defining a resource and mine planning. Often, you just can't afford enough core drilling to pinpoint contacts well-enough for efficient mine planning. At the Finsch Diamond Mine in South Africa, they have successfully utilized gamma logging of percussion drill chips to obtain centimeter-scale accuracy.
A Goldschmidt abstract. The authors studied peridotite xenoliths in a north-south transect across the Slave craton. In the central and southern Slave they found dominantly Neoarchean Re-depletion Os model ages (TRD). Moving north the Archean influence lessens. At Artemisia in the north Slave craton, 70% of the xenoliths yielded model TRD ages of around 1.3 by, the time of the Mackenzie dyke event, with most of the remainder having TRD ages that appear to reflect Paleoproterozoic orogenic events.
I find all the stories of the exploration and development of the Marange diamond deposits in Zimbabwe fascinating including analysis of the social implications. This study concludes: "The overriding argument of this study is that artisanal mining has continued to be a sustainable livelihood avenue in spite of its well-known negative impacts."