Stable ‘Non-Traditional’ Isotopes - Application of Geochemical Tracers to Fluvial Sediment - page 129

Fig. 5.5 Summary of published Hg isotopic data (from Bergquist and Blum 2009 ). Horizontal
bars show range in mass-dependent fractionation ( a ) and mass-independent fractionation ( b ). The
vertical bars represent the estimated crust- and mantel-derived Hg. Data sources include: 1. Hin-
telmann and Lu ( 2003 ), Smith et al. ( 2005 , 2008 ); 2. Smith et al. ( 2008 ); 3. Lauretta et al. ( 2001 );
4. Sonke et al. ( 2008 ), Zambardi et al. ( 2009 ); 5. Jackson et al. ( 2004 ), Foucher and Hintelmann
( 2006 ), Biswas et al. ( 2008 ), Ghosh et al. ( 2008 ), Jackson et al. ( 2008 ), Foucher et al. ( 2009 ), Gehrke
et al. ( 2009 ); 6. Biswas et al. ( 2008 ), Ghosh et al. ( 2008 ), Carignan et al. ( 2009 ), Bergquist and
Blum ( 2009 )

Mass-independent fractionation of the odd isotopes is reported as the difference
between the measured

201 Hg values to the predicted mass-dependent
values as follows (Blum and Bergquist 2007 ):

199 Hg and

ʴ ʴ

199 Hg 199 Hg 202 Hg

ʔ = ʴ − (ʴ · 0 . 252 ) (5.4)

and

201 Hg 201 Hg 202 Hg

ʔ = ʴ − (ʴ · 0 . 752 ) (5.5)

Studies of the effects of metallurgical processes on Hg isotopes suggest that waste
products will often possess a distinct Hg isotopic signature. It should come as no
surprise, then, that the initial studies of Hg isotopes within samples from sedimentary
deposits, including those within riverine environments, have demonstrated that Hg
sources have the potential to determine both Hg provenances and loading histories
(Sonke et al. 2010 ; Foucher et al. 2009 , 2013 ; Feng et al. 2010 ; Mil-Homens et al.
2013 ; Yin et al. 2013 ). Sonke et al. ( 2010 ), for example, found that within the Lot
River basin, France metal refining resulted in slag residues that exhibited heavy Hg
isotopic values. As a result, both the mass-dependent and mass-independent Hg iso-
topic signatures of contaminated sediments were isotopically heavier than that of the
local background materials. As was the case for Cd, Cu, and Zn, a primary concern
in the use of Hg isotopes is whether the contaminated source sediments will retain
the original signature during its dispersal through the river system or whether a wide