J-10's are very low Ca and high Cr pyropes that lie within the G-10 field.
Common or reasonably accessible references
Mid-Continental Diamonds, 1993 GAC-MAC Symposium Volume eds. K.P.E. Dunne and B. Grant
Contains abstracts and short papers by many authors covering topics of quaternary geology, geochemistry, structure, petrography plus specific examples in Canada.
Journal of Geochemical Exploration Volume 53 Nos. 1-3, Special Issue, Diamonds Exploration: Into the 21st Century, ed. W.L. Griffin.
Contains many more technical papers on topics of quaternary geology, geophysics, geochemistry, structure, petrography plus specific examples worldwide.
Includes: Specific references re: your questions.
Gurney and Zweistra's reference to G-10 differences in Group I and Group II kimberlites using Driekoppies and Buljah as examples.
Mitchell's paper referencing orangeite as a replacement term for Group II kimberlite which to date is found only in South Africa.
Searching for diamonds in Canada, (1996) ed. LeCheminant, Richardson, DiLabio, and Richardson. GSC Open File 3228
Fipke et al. (1995) GSC Bulletin 423.
And standard which very few people actually can get, let alone take the time to read.
Fipke et al. (1991) GSC Open File 2124
Dave |
