Open File Report 2009-21

Open File Report 2009-21

OFR 2009-21

Compositions of Low-Chromium Garnet Xenocrysts from Selected Ultramafic Bodies in the Northern Alberta Kimberlite Province

Author(s) Eccles, D.R. Date 2009-12-15

To date, nearly half of the single-phase syngenetic diamond inclusions recovered and documented from the Buffalo Head Hills kimberlite field are eclogitic in paragenesis. Despite this predominance of eclogitic diamond inclusions, previous mantle xenolith and xenocryst studies in northern Alberta are limited primarily to peridotitic assemblages.

This report provides a comprehensive set of low-chromium garnet xenocryst compositions for selected ultramafic bodies from the Buffalo Head Hills and Birch Mountains fields in north-central and northeastern Alberta.

The release of these data and interpretations will help diamond explorers evaluate low-chromium garnet xenocrysts recovered and analyzed in surficial heavy-mineral surveys. The results of our study show that there is no unequivocal link between the low-chromium garnet xenocrysts cited here and the Buffalo Head Hills diamond-inclusion data of other reports.