Economic Geology; January 2005; v. 100; no. 1;
p. 43-61; DOI: 10.2113/100.1.0043
© Society of Economic Geologists
Click on image to view larger version.
FIG. 15. A. Plot of Pd (ppm) vs. Ir/Pd for samples from the southern Roby,
Twilight, and High-Grade zones compared to other PGE deposits. Note that the Lac
des Iles data plots along the general trend of other orthomagmatic deposits. B.
Plot of Pd (ppm) vs. Pt/Pd for rocks from the Lac des Iles deposit. Note that
the majority of the melanocratic rocks show comparable Pt/Pd ratios, but samples
from the High-Grade zone have higher Pd and therefore low Pt/Pd. The scatter is
most likely due to a nugget effect of coarse-grained platinum group minerals.
Data sources: Komatite-hosted deposits (Picard et al., 1995); Marathon deposit
in the Coldwell Complex, Ontario (Good and Crocket, 1994); Duluth Complex
(Theriault et al., 1997); J-M reef (J-M: Naldrett, 1981); Merensky reef,
Bushveld Complex (M: Naldrett, 1981).
Copyright © 2008 by Society of Economic Geologists
