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 is President and CEO of Craton Minerals Ltd., a Vancouver-based private diamond exploration company focused on discovering North America's next diamond district. He is also President of JBC Ventures Ltd., a consulting company specializing in mineral exploration and community and government relations. 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. Before that, Brooke was Vice President, Exploration for Ashton Mining of Canada Inc. Under his leadership, Ashton and their partner SOQUEM discovered the Renard diamond district in Quebec where the Renard Diamond Mine commenced production in 2016. From 1982 to 1997, Brooke was an Exploration Geologist and Regional Manager for Exmin Corporation where he conducted diamond exploration programs throughout the United States. He holds a BSc in Geology from Indiana University and an MSc in Economic Geology from the University of Arizona.
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 2020: The annual international Goldschmidt conferences are focused on geochemistry and related subjects. This year the conference was scheduled to be held in Hawaii from June 21-26, but of course, it was virtual. Pat cites one page abstracts from 29 presentations on contemporary research related to diamonds and kimberlites. You can download the abstracts for free.
BOTSWANA JOURNAL OF EARTH SCIENCES 2018 ISSUE: This month, after Andy Moore brought it to her attention, Pat features a 2018 issue of the Botswana Journal of Earth Sciences that had six great papers on the diamond biz in Botswana and three of those papers are summarized. The papers are free downloads.
A free download that is a summary of the worldwide state of diamond exploration, financing alternatives and the diamond business in general and in Africa. It was written in 2019 before COVID-19 hit. For the mining/exploration investment community, diamonds are not top of mind at the moment, especially for explorers. The author states: "Junior "mine finders" have been the hardest hit. Their agility, tenacity, and appetite for risk are not sufficient to attract the funding required, even at the greenfield stage". It's estimated that there are 2.5 billion defined carats in the ground in the world today which would last about 18 years at the current consumption rate of 140 million carats/year. New discoveries are needed and juniors are not doing a lot of exploration. Mr. Campbell gave a talk on financing diamond projects in southern Africa at the 2020 PDAC diamond session.
Good summary of the discovery, development and operation of the Karowe diamond mine in Botswana. The AK-6 kimberlite which supports the mine was discovered over 50 years ago by De Beers, and over 40 years later, in 2012 the mine was put into production by Lucara Diamonds and it is a great success story. The world has learned a lot about Type 2 diamonds from Karowe.
I am interested in all the stories around the Marange alluvial diamond fields in Zimbabwe, one of the largest alluvial diamond deposits in the world. The field was discovered by De Beers and there was a crazy rush into the area in 2006 when thousands of artisanal miners arrived. The rush seemed to come out of nowhere without much warning. The government sent in the military to "calm things down" and some people were displaced from their homes. This paper summarizes some of the social effects experienced by the Chiadzwa people.
The paper is a free download. Mr. McKechnie was in charge of DeBeers' worldwide exploration programs for many years. He sees opportunities for new discoveries to be made in southern Africa and cites the potential for improved processing technologies to bring new resources into play, both in new and known deposits. There is a good historical summary of the diamond business in southern Africa with some great charts.
Jwaneng in Botswana is one of the richest diamond mines in the world. This is a summary of its discovery and evaluation by two people that were there. Discovered in 1973, Jwaneng produced 10.4 million carats from 7.9 million tones (1.32 cpt) in 2015, and it has many more decades of life.
The 156-138 million year old Chidliak diamond district was discovered in 2008 by Peregrine Diamonds, with an assist from BHP Billiton. The district is thought to be underlain by a remnant of the Archean North Atlantic craton. The craton was rifted into at least three fragments: the Nain province in northern Quebec, southern Greenland and the Lewisian complex in northwestern Scotland. The results of a previous study of peridotite xenoliths from Chidliak suggested that the Archean basement underlying the district was likely contiguous with the North Atlantic craton at one time. Nineteen eclogite xenoliths from Chidliak kimberlites were interpreted to be subducted crustal basalt and gabbro that was metamorphosed to eclogite facies and resided in the pervasively metasomatized peridotitic mantle prior to being picked up by ascending kimberlites. They determined that the Chidliak eclogites equilibrated in the diamond stability field between 840 and 1410 degrees centigrade and 4.1-7.4 GPa. There is a great summary of the tectonic history of the North Atlantic craton with an accompanying map.