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 .
Hello from North Vancouver where I have five days left in my two week "self-quarantine". Those returning to Canada from outside the country are required to "self-quarantine" for two weeks. In a short month, COVID-19 has come to dominate everything and affect us all. Let's hope we get back to business as close to usual as possible soon. Avoid that virus!!
Prior to 2008, most general geologic interpretations of the Hall peninsula on south Baffin Island showed it as being underlain by Paleoproterozoic basement, or at least Archean basement that was dramatically altered in the Paleoproerozoic. There was however, one interpretation that showed the peninsula as being a potential Archean microcontinent that had become separated from the rest of the North Atlantic craton which includes parts of Labrador, Scotland and Greenland. The possibility of Archean basement was one of the factors that influenced BHP and Peregrine when they targeted the area for diamond exploration in 2005. This exploration ultimately led to the discovery of the Chidliak diamond district in 2008. Using xenolith samples from Chidliak kimberlite drill core, Dr. Kopylova and her team at UBC have confirmed that the area was once part of the North Atlantic craton, separated from other portions of the craton by a rifting event 150 million years ago.
Dr. Cummings has been a student of glacial dispersion trains for a long time and many of us have been touched by his work. The 2018 paper describes the mechanics of dispersal train formation and the accompanying map depicts major trains in North America. The authors put together the map from many years of work and research: 12.9 MB Poster Quality File with 10 maps. There is also an excellent list of references for the "train scholar".
The Man craton comprising parts of Sierra Leone, Liberia and Guineau in west Africa has seen a lot of diamond exploration, with the Koidu mine in Sierra Leone probably the most famous locality. This is a detailed study of the Jurassic-aged Tongo kimberlite dyke in Sierra Leone and the 800 my old Weasua lamproite cluster in Liberia with some good background information on the region.
The carbon isotope characteristics of 144 p-type and e-type diamonds from localities throughout the world representing an age range of 3.5 to 1.0 billion years were studied. They found that there is no systematic variation with time in the mantle carbon isotope record since before 3 billion years ago.
A very interesting study of the thermal and tectonic history of the Nuna supercontinent in North America which came together during the Paleoproterizoic and includes the Slave, Rae, hearne and Superior Cratons. There are very good descriptions of some of the tectonic domains. The following summarizes thinking related to the Nuna supercontinent "The upper plate Churchill Province (amalgamated Rae and Hearne cratons) has experienced extensive deformation, metamorphism and reworking throughout the late Paleoproterozoic, while the Slave and Superior provinces, both occupying generally lower plate positions, experienced much more subdued tectonic histories." A compilation of >2000 K-Ar and 40Ar/39Ar cooling ages outlined the cooling history of the Churchill province and confirmed that there was extensive thermal reworking prior to the late Paleoproterozoic.