This thesis models the 3D hydrothermal alteration and gold mineralization in the Nuuluk area of southwest Greenland. Data from over 40 years of exploration, including drill cores and surface samples, were compiled and analyzed geochemically. Four mineralized zones were identified, with gold concentrations correlated to arsenic and copper. The gold occurs in boundary areas between rock types and structures. While individual values are low, modeling the gold volumes provides insight into the potential in the area. More data collection is needed but the project has been re-opened for further investigation.

1. BACHELOR
THESIS:
3D
modelling
of
hydrothermal
altera>on
and
Au
mineralisa>on
in
the
Nuuluk
area
Tartoq
gold
province
(SW
Greenland)
Sara
E.
Hoffritz
Done
in
co-­‐opera>on
with
University
of
Copenhagen
and
Geological
Survey
of
Denmark
and
Greenland

2. Nuuluk
Figur Map showing location of Nuuluk in SW Greenland and
the regional geology. Map is modified after GEUS (figure:
Henriksen 1968, Escher og Jensen 1974, Jensen 1975)
Figur
Map
of
the
loca>on
of
different
drill
cores
(red
dots),
both
diamond
drilling
in
the
west
and
winkie
drillings
in
the
east
along
with
surface
samples
shown
by
their
gold
value
(Figur:
King,1985)

3. Background
• More
than
40
years
of
explora>on
• Two
parallel
altera>on
zones
of
old
meta-­‐
volcanics
in
a
classic
greenstone
belt
which
has
been
hydrothermally
altered
by
carboniferous
fluids
• Rock
types
are
schist
and
hydrothermal
altered
meta-­‐volcanics
• 12.30
ppm
in
the
Eastern
zone
• 6.63
ppm
in
the
Western
zone

4. METHODE

5. Cross
sec>ons
West surface East
Au (127 ppb/4m)
DH3 & DH4
Au (68 ppb/4m)
DH1 & DH2
Au (61 ppb) Au (887 ppb)
Profile A
DH3
97 m
Au (86 ppb/4m)
Au (516 ppb/2m) Au (78 ppb, projected)
West surface East
DH4 Au (132 ppb, projected)
109 m
Au (730 ppb/2m)
Au (217 ppb/2m)
Au (6.65 ppm/2m)
DH5
DH1
134 m
DH2
109 m
DH5
125m

6. Geochemical
features
Profile log and sample analysis

7. Imported
data
From
reports
from
Nunaoil,
Greenex
and
GEUS
• Drill
hole
data
– Loca>on,
depth,
azimuth
and
dip
– Lithology
– Measurements
of
Au,
As
and
Cu
– Structural
measurements
• Surface
samples
-­‐>
topography

8. Lithology

9. Lithology

10. Lithology
-­‐
Structures

11. Gold
occurrences
HALOES:
Red: 95< ppb (!)
Orange: 80-95 ppb
Yellow: 60-80 ppb
Western
upper
zone
Bright: 50-60 ppb
Eastern,
northern
zone
Western
lower
zone
Eastern,
southern
zone

12. Lithology
+
Gold
occurences

13. Results
• Modelling
of
gold
volumes
are
possible
in
spite
of
low
values
and
gives
a
good
idea
over
the
poten>al
in
the
area
• The
gold
is
in
boundary
zones
with
lower
stability
–
but
in
different
rock
types
–
structures
?
• There
are
at
least
four
mineraliza>on
zones
• Gold
correlates
with
As
and
Cu
• There
is
a
connec>on
with
high
gold
values
and
the
graphite-­‐
and
magne>te
schist
• Old
and
new
data
can
give
a
3D
view
of
the
geometry
of
the
gold
occurrences
• More
data
is
needed
• GEUS:
Project
re-­‐opened
and
area
will
be
more
inves>gated
next
field
season