http://mom.gov.af/Content/files/MoMP_LITHIUM_Midas_Jan_2014.pdf
Lithium in Afghanistan
Figure 1. Lithium occurrences in Afghanistan on
a low
–
resolution
Landsat
image,
with major tectonic features, intrusive
rocks and saline lakes.
Geology of Afghanistan
Afghanistan has a complex geolog
y due to its position
o
n
the junction between the Indo
–
Australasian and Eurasian
crustal plates. Its geology is composed of a series of
terranes that broke away from the main Gondwana
supercontinent before coll
iding, with each other or
with
the Eurasian plate. Ultimately, all the terranes
became
accreted onto the southern margin of the
Eurasian plate.
The accretionary events started in the
Cretaceous and have
continued until recent times. The
final closure of the
Neo
–
Tethys
ocean between the Indo
–
Pakistan and Eurasi
an
plates caused the Himalayan
orogeny. In the Hindu Kush
region of NE Afghanistan
downward buckling of the
intervening crust and later
uplift of these metamorphosed
remnants produced high
–
grade metamorphic rocks
, anatexis
and
S
–
type
granites. Li
–
bearing pegmatites are in the
main,
restricted to Nuristan in NE Afghanistan
adjacent to
the Laghman granite complex (Figures 1
and 7).
Introduction to Lithium
Lithium, despite being called a ‘rare metal’, is not that
rare
in the Earth’s crust and its crustal average is about
35 ppm.
Until recently lithium has been used only in
small niche
markets in the glass and ceramics industry,
in high
temperature greases and in the chemical
industry.
Lithium
h
as now become an
important element in the
emerging, digital and
low
–
carbon
economy and lithium
batteries will probably power the
next generation of
electric cars, causing demand for
this ‘rare metal’ to grow
rapidly over the next 10 years.
A
t the present time
(2013
)
suppli
es are broadly in
balance with demand
.
But d
emand
is predicted by
many forecasters to exceed supply in 2020.
The two main sources of lithium are hard rock sources
in
pegmatites and in solution within continental brines,
both of
which are present in Afghanistan.
Figure 2. Location of the
lacustrine halite occurrences, lakes, main rive
rs and major faults on a shaded
relief background
from the USGS GIS (Peters et al., 2007).
The bulk
of the world’s
supply
of lithium
comes from
salt
or playa lakes, also called ‘salars’ after their Span
ish name.
Afghanistan has similarities with the South American
deposits in the so
–
called ‘Lithium triangle’
of Argentina,
Bolivia and
Chile
with
its
elevated enclosed
basins
, high
evaporation rates and, in some cases
,
young volcanic
rocks.
Lithium in Afgh
an Lake Sediments
Afghanistan has a number of
similar
lakes (
Figure
2).
Reconnaissance sampling
(Figure 3) by the Dep
artment of
Defense (DoD, 2011)
indicated high Li levels i
n lake
sediment (Table 1). The
lakes have not been syst
ematically
sampled for lithium
or other
potentially ec
onomic elements,
such as K, B,
Rb
, U
or Cs
,
so it is
not
possible
at present
to
give
any
estimates of resources. The readily available
figures are given by Abdullah et
al
.
(
1980).
Figure 3. The Afghanistan Geological Survey works in
partnership with international geo
–
scientific organizations
to produce a compelling assessment of Afghan resources.
Examination
of
known
salt
lakes (
Figures 4
–
6)
on
detailed
Landsat ETM+ images on the USGS GIS (Davis, 2007)
shows that
the water shows a blue reflec
tance and the area
of this reflectance has been taken as the present surface
area of the lake (Figure 4). White areas around the lakes
are pr
obably salt flats, but they could be gypsum, which
normally shows a light blue
color
on the 7
–
4
–
2 band image.
Table 1. Analyse
s of Afghan lake sediments from
reconnaissance sampling (DoD, 2011).
Lake
B
ppm
Na
%
Li
ppm
Sr
ppm
Mg
%
Chankansar
(Nimroz)
1.54
49
560
1.75
Dasht
–
e
–
Nawar
110
10.5
99
894
8.7
Gowde
Zareh East
110
25.1
36
358
1.7
Namakas
–
e
–
Herat
48
30.3
41
461
0.8
Crustal Abundance
9
2.27
18
384
2.8
The DoD team drilled to 10 metres at multiple location in
Namaskar
–
e
–
Herat (DoD, 2011). The team believes
samples were collected in the Halite zone, a key indicator
of correct sample location, and found signs of
hydrothermal activity at the site