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TitleDiamond sources beneath the Hall Peninsula, Baffin Island, Nunavut: preliminary assessment based on microdiamonds
AuthorNichols, K M A; Stachel, T; Pell, J A; Mate, D J
SourceCanada-Nunavut Geoscience Office, Summary of Activities 2012, 2013 p. 113-120
Year2013
Alt SeriesEarth Sciences Sector, Contribution Series 20120346
PublisherCanada-Nunavut Geoscience Office
Documentserial
Lang.English
Mediapaper
File formatpdf
ProvinceNunavut
NTS25O/13; 25O/14; 25O/15; 25O/16; 25P/13; 25P/14; 26A/04; 26B
AreaBaffin Island; Hall Peninsula
Lat/Long WENS -68.5000 -65.0000 65.0000 63.5000
Subjectseconomic geology; mineral potential; kimberlites; diamond; sedimentary rocks; Conodonts; Chidliak kimberlite province; Paleozoic
Illustrationslocation maps; photomicrographs; pie charts
ProgramCanada-Nunavut Geoscience Office, Funding Program
LinksOnline-Enligne
AbstractThis study is part of the Canada-Nunavut Geoscience Office's Hall Peninsula Integrated Geoscience Program, a multiyear bedrock and surficial geology mapping program with associated thematic studies. The Chidliak kimberlites, located 120 km northeast of Iqaluit, on the Hall Peninsula, southern Baffin Island, tap mantle source regions of unknown paragenesis, age and history; the recently discovered kimberlites have proven to be diamondiferous. Of the 44 kimberlites (out of 62) tested for diamonds, 41% of the kimberlites contained commercial-sized diamonds. Approximately 740 microdiamonds ( 600 m) have been provided by Peregrine Diamonds Ltd. for this study, of which 102, within the size range of 210 to 600 m, are presented in this paper. Microdiamonds were separated from the kimberlite by SRC Geoanalytical laboratories of Saskatoon, Saskatchewan, using crushing techniques and caustic fusion. Themicrodiamonds were then sorted into sieve sizes (600 m, 425 m, 300 m, 210 m, 150 m, 106 m).
This project will focus on microdiamond characteristics, such as morphology, colour, carbon isotopic composition, nitrogen concentration and nitrogen aggregate states, to constrain the upper-mantle source, themicrodiamond residence time in the mantle and the conditions of diamond formation. After the physical description of themicrodiamonds, the principle focus for this study will be to fingerprint their possible mantle source regions. This will be done by determining the nitrogen characteristics and carbon isotope compositions of the microdiamond samples using spatially highly resolved (15 mspot size) analyses obtained via the state-of-the-art Cameca IMS1280 ion microprobe. Here we report preliminary findings on the microdiamonds from two kimberlite samples (P5500 and P6807) on the Hall Peninsula.
GEOSCAN ID292137