1. Elmi Assadzadeh, G.*, Samson, I.M., Gagnon, J.E.
Department of Earth and Environmental Sciences, University of Windsor, Windsor, Ontario, Canada, N9B 3P4
*elmias@uwindsor.ca
University of Windsor
! ! ! ! thinking forward
Acknowledgement
The funding of this research is provided by
NSERC.
Dr. Dave Sinclair is thanked for providing some
samples used in this research.
References
Gagnon, J. E., Samson, I. M., Fryer, B. J., and
Williams-Jones, A. E., 2003. The Canadian
Mineralogist 41, 365-382.
Kooiman, G. J. A., McLeod, M. J., and Sinclair, W.
D., 1986. Economic Geology 81, 1356-1373.
Sinclair, W. D., Kooiman, G. J. A., and Martin, D. A.,
1988. Geological Survey of Canada, 201-208.
Sinclair, W. D., Kooiman, G. J. A., Martin, D. A.,
and Kjarsgaard, I. M., 2006. Ore Geology Reviews
28, 123-145.
0.1
1
10
100
1,000
La
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
fluorite associated with base metals
0.1
1
10
100
1,000
La
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
barren fluorite
0.1
1
10
100
1,000
La
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
fluorite associated with wolframite and molybdenite
0.1
1
10
100
1,000
10,000
La
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
fluorite associated with cassiterite
0.1
1
10
100
1,000
10,000
La
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
fluorite associated with wolframite
0.1
1
10
100
1,000
La
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
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! fluorite associated with molybdenite
Fluorite Associations
Conclusions
The zoning patterns in fluorite
associated with Sn and W
mineralization suggests a complex,
dynamic fluid evolution during
cassiterite and wolframite
deposition, that may reflect the
interplay among fluids of different
character and origin. This is in
contrast to the fluid environment
during Mo precipitation and
subsequent stages of base metal
deposition, where zonation patterns
are less complex. These data also
illustrate that fluorite chemistry
correlates with mineralizing events
and thus has possible applications in
exploration for Sn-W-Mo deposit.
The sum of rare element
concentration can positively be used
as an exploration tool to distinguish
mineralized
from non-mineralized
zones within a deposit. Fluorite
samples from the Mount Pleasant
deposit show flat REE patterns with
negative Eu anomaly. This trend is in
complete agreement with fluorite
samples from granitic magmatism
reported by Gagnon et al., 2003.
Wolf
Fl
Hem
Fl
Cst
Qtz
Chl
Apy
Gn
Sp
Fl
Moly
Fl
Fl
Fig. 2. A-D) Fluorite associated with cassiterite, wolframite, molybdenite, base metals E) Barren fluorite.
Fluorite associated with base metals
(fluorite + galena+ sphalerite)
Barren fluorite
Fluorite associated with molybdenite
(fluorite + molybdenite)
Fluorite associated with wolframite
(fluorite + wolframite + hematite)
Fluorite associated with cassiterite
(fluorite + topaz + arsenopyrite + cassiterite)
Fig. 3. Cathodoluminescence images of fluorite associated with A) cassiterite, B) wolframite, C) molybdenite,
and D) Barren fluorite.
Cathodoluminescence
Laser Ablation ICPMS
Our results also show that dark CL zones have significantly higher
REE content than bright CL zones (Fig. 8).
The Trace Element Chemistry and Cathodoluminescence Characteristics of Fluorite in
the Mount Pleasant Sn-W-Mo Deposits
Laser-ablation ICPMS analyses of various
fluorite types show that fluorite from the FTZ
has significantly higher W/Sn ratios than
fluorite in the NZ (Fig. 4).
Fig. 5. illustrates the chondrite-normalized concentrations of rare
earth elements (REE) for different fluorite types. Our data show
that all fluorite types have flat REE patterns with most crystals
having negative Eu anomalies; the exception is fluorite associated
with base-metal sulphides, which has flat or positive Eu
anomalies. Our data is consistent with fluorite chemistry from
other granite-related mineralization (Gagnon et. al, 2003). Rare
earth element concentrations are up to several orders of
magnitude higher in fluorite associated with cassiterite,
wolframite, and molybdenite than in barren or base-metal
associated fluorite (Fig. 6).
Fig. 4. W/Sn ratio of various fluorite types.
Fig. 6. Chondrite-normalized REE plots for fluorite associated with A) cassiterite
B) wolframite C) molybdenite, D) base metals, D) barren fluorite, and E)
wolframite+molybdenite.
0.1
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10
100
1,000
10,000
Range
LaN NdN CeN PrN SmN EuN GdN TbN DyN HoN ErN TmN YbN LuN
NZ
FTZ
Figure 7. shows that the concentration of REE are generally higher
in the FTZ relative to the NZ. The only exception is Eu with
concentrations that are lower in FTZ relative to the NZ (Fig.6).
Fig. 7. the concentration of REE for the NZ and the FTZ. The diagram shows that
except for Eu, the concentration of all REE are significantly higher in the FTZ.
In addition, REE concentrations are
significantly higher for fluorite that is
associated with cassiterite, wolframite,
molybdenite, and base metals relative to
those of barren fluorite veins (Fig. 5).
Fig. 5. Plot of Sum REE for various fluorite types show
that barren fluorite has significantly lower REE content.
Fig. 8. Chondrite-normalized REE plot for
bright CL (core), dark CL (middle zone), and
dark CL (rim) in fluorite associated with
cassiterite. Bright CL zone at the core has
the lowest REE content.
Core
Middle zone
Rim
Introduction
The focus of this research is to understand the
compositional variation of fluorite crystals within
an individual deposit. Specifically, the trace
element composition of barren fluorite and
fluorite that is associated with various styles of
mineralization were determined using LA-ICPMS
to assess differences between the chemistry of
various types of fluorite crystals, and if such
differences can be used as an exploration tool to
assess mineralizing potential.
Study Area
The Mount Pleasant Sn (-W-Mo) deposit
comprises two hydrothermal breccia pipes and
mineralized granite apophyses, namely, the Fire
Tower Zone (FTZ) and the North Zone (NZ) that
are located in approximately 1 km apart (Fig. 1).
The FTZ contains a significant W-Mo with minor
Sn mineralization and the NZ hosts several major
Sn deposits: Endozone (EZ), Contact Crest (CC),
Contact Flank (CF), and DeepTin Zone (DTZ), as
well as minor W-Mo mineralization (Kooiman et
al., 1986; Sinclair et al., 1988). Ultimately, we are
interested in knowing if these differences reflect
fluid metal concentrations, and if these are
reflected in mineral chemistry.
Fig. 1. Cross-section through FTZ and the NZ at Mount
Pleasant (Sinclair et al., 2006).
0.001
0.01
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Range
W/Sn
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!
!
!
!
!
!
fluorite associated with cassiterite
fluorite associated with wolframite
barren fluorite
fluorite associated with base metals
! fluorite associated with molybdenite
fluorite associated with wolframite and molybdenite
Fluoriteassociatedwithcassiterite
1
10
100
1000
10000
Counts
La
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
Bright CL (core)
Dark CL (middle zone)
Dark CL (rim)
0.001
0.01
0.1
1
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100
1,000
Range
W/Sn
!
!
!
!
!
!
!
fluorite associated with cassiterite
fluorite associated with wolframite
barren fluorite
fluorite associated with base metals
! fluorite associated with molybdenite
fluorite associated with wolframite and molybdenite
Cst
Wolf
BM
Moly
Moly+Wolf
Barren
W/Sn
NZ FTZ
10
100
1000
10000
100000
1000000
Range
Sum (REE)N
!!!!
!
!
!
fluorite associated with cassiterite
fluorite associated with wolframite
fluorite associated with base metals
! fluorite associated with molybdenite
barren fluorite
fluorite associated with wolframite and molybdenite
Cst
Wolf
BM
Moly
Moly+Wolf
Barren
∑REENconcentration/chondrite
concentration/chondrite
concentration/chondrite
LaN CeN PrN SmN EuN GdN TbN DyN HoN ErN TmN YbN LuNNdN