More information?
mallan@doct.ulg.ac.be
nathalie.fagel@ulg.ac.be
www.ages.ulg.ac.be
Mohammed Allan
a
, Gaël Le Roux
b, c
, François De Vleeschouwer
b, c
, Nathalie Fagel
a
a
AGEs, Département de Géologie, Université de Liège, Allée du 6 Août, B18 Sart Tilman B-4000, Liège, Belgium;
bUniversité de Toulouse ; INP, UPS; EcoLab; ENSAT, Avenue de
l’Agrobiopole
, 31326 Castanet Tolosan, France ;
cCNRS; EcoLab; 31326 Castanet Tolosan, France
206
Localisation
Aims
To determine the extent of atmospheric TM
contamination, it is necessary to identify the main past
and present sources of TM emissions. Peat bogs have
a great potential to record anthropogenic inputs via
their constituting mosses, because they draw their
nutrients only from the atmosphere. We determine
precisely the chemical depth-profiles of V, Cr, Co, Ni,
Cu, Zn, As, Cd, Sb, Pb, and Pb isotopes, in a high
resolution peat-sampled sequence. We investigate
possible mobility of TM by comparing some elements
(Pb, Cu, Ni, Cr, V, and Zn) with another
high-resolution peat sequence. By coupling cluster analyses
and Pb isotopes, we identify TM relationships and
sources since the last 200 years. We finally compare
our results with previous investigation in a low
resolution peat core focused on Pb in the same area
(De Vleeschouwer et al., 2007) and in Western
Europe.
Material
• Peat cores were collected in 2008.
•Ages of top layers were calculated using
210
Pb decay and the CRS model (Appleby,
2001).
14
C measurements were performed
with NEC 0.5MV Pelletron spectrometer in
Poznan Radiocarbon Laboratory, Poland. An
age model was obtained by combining the
results with the
210
Pb..
•The concentrations of major and trace
elements were measured by ICP-MS, at the
Paul Sabatier University-Toulouse, France.
•Lead isotope ratios were measured on a
MC-ICP-MS
(DSTE,
University
of
Brussels).
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We thank the Walloon Region as well as the F.N.R.S
for funding this project. We also thank all personnel
who participated in this project.
•The Misten peat bog is heavily polluted in metals and metalloids
•The main trends in TM concentration profiles suggest common sources of these elements and support the view that TM (except Zn and Cd) are immobile in peat. Other TM are highly enriched in peat surface layers and may indicate that they are carried on by large unweathered particles. •The lead isotope data and statistic methods were used to identify the independent historical TM sources.
•Industrial Revolution is characterized by different sources such as regional Pb ore mining, coal combustion and steel industry (“Sillon Sambre et Meuse”), which declined during the sixties-seventies. • Pb isotopes in the top layers fingerprint a secondary recent source, which remains to be identified.
C
on
cl
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Atmospheric deposition of trace metals and metalloids recorded by Misten peat
(Hautes-Fagnes, Belgium) during the Industrial Revolution
Acknowledgements
Profiles of major and trace element concentration (µg g
-1),
206Pb/
207Pb ratios, and bulk density
(g.cm
-3) versus depth. Black line corresponds to TM concentration measured in 01W core and
gray line some TM concentration measured in 06W core
Calculated total atmospheric fluxes (in mg. m
-2. yr
-1) of Pb, Cu, Sb,
Ni, As, Cr, V, Co, Cd and Zn for the Misten peat bog core 01W.
Dendogram for AR of TM, Ti and Al in the Misten peat bog for different periods. a) AR of TM, Ti and Al measured between 1400 and 1700 AD, b) AR of TM, Ti and Al measured over the Industrial Revolution, c) AR of TM, Ti and Al measured for the interval between 1990 and 2008, d) TM emissions measured in Walloon region between 1990 and 2008.