26 February 2018
Savannah Resources Plc
200% Increase in Lithium Mineral Resource Estimate to 9.1Mt and
Significant Exploration Target at Mina do Barroso Lithium Project,
Portugal
Savannah Resources plc (AIM: SAV and SWB: SAV)
('Savannah' or 'the Company'), the AIM quoted resource development
company, is pleased to announce a revised JORC 2012-Compliant
Inferred Mineral Resource Estimate and an initial Exploration
Target for the Mina do Barroso Lithium Project (‘Mina do Barroso’
or the ‘Project’), located in northern Portugal (Figure
1).
Overview:
- ~200% increase in Inferred Mineral Resource Estimate to 9.1Mt
at 1.03% Li₂O containing 94,100t of Li₂O using a 0.5% Li₂O cut-off
grade
Deposit |
Tonnes (Mt) |
Li2O% |
Li2O Tonnes |
Reservatorio |
3.2 |
1.00 |
32,000 |
Grandao |
5.5 |
1.04 |
56,500 |
NOA |
0.5 |
1.23 |
5,600 |
Total |
9.1 |
1.03 |
94,100 |
- Mineral Resource Estimate covers three of at least eight known
pegmatites on the Mina do Barroso Mining Lease
- Further drilling is now underway utilising both Reverse
Circulation (RC) and diamond drill rigs, targeting both down dip
and strike extensions of currently defined Mineral Resource
Estimate
- Further Mineral Resource Estimate updates are expected during
2018 as the drill programme advances – Grandao resource is based on
the first 40 holes drilled only (of the 61 drilled to date)
- Savannah remains on track to make a development decision by the
end of the year
- In addition, an initial Exploration Target* for the Grandao and
Reservatorio deposits of 8-12Mt at 1.0% to 1.2% Li₂O has been
defined. This gives a project target (including Mineral Resources)
of 17-21Mt at 1.0-1.2% Li₂O
*Cautionary Statement: The potential quantity and grade of the
Exploration Targets is conceptual in nature, there has been
insufficient exploration work to estimate a mineral resource and it
is uncertain if further exploration will result in defining a
mineral resource.
Savannah’s CEO, David Archer said: “The Mineral
Resource Estimate defined from our 2017 drill programme supports
our belief that Mina do Barroso is one of Europe’s most promising
lithium projects. Whilst we are delighted with the results to-date,
the Exploration Target underscores the potential to increase the
aggregate Mineral Resource Estimate over the coming months,
especially as we now have two drilling rigs on site.
“This potential is matched by excellent first pass metallurgical
test results with conventional processes, the spodumene dominant
nature of the deposits, open-cut potential, access to excellent
infrastructure including roads and ports, and the premier nature of
the jurisdiction.
“Looking ahead, we are progressing with more detailed, second
pass metallurgical test work and hope to shortly commission a
Scoping Study to lead into a Definitive Feasibility Study later
this year. We believe that we are moving towards defining a project
that will sustain one of Europe’s most significant, long-term,
lithium mining operations.”
Figure 1. Mina do Barroso Project Summary Map
showing prospects and drilling completed to date
Mineral Resource Estimate
A Mineral Resource Estimate for the Grandao and NOA Lithium
Deposits has been completed by Payne Geological Services Pty Ltd,
an external and independent mining consultancy - http://www.paynegeo.com.au/paul-payne. The Deposits
form part of Savannah’s Mina do Barroso Lithium Project, located in
northern Portugal.
The Grandao Deposit comprises two separate pegmatite intrusions.
The upper part of the Deposit occurs within a broad, flat-lying
pegmatite body with a typical thickness of 20m-40m. The lower
portion appears to be a steep dipping dyke, which is 15m-20m in
true width. The geometry of the lower zone is not clear due to the
current sparse drilling in this portion of the Deposit, where only
three holes drilled to the depths to intersect the zone. The
overall Grandao Mineral Resource Estimate is based on results from
40 RC drill holes completed by Savannah in 2017. Both pegmatite
zones remain open along strike (Figure 2-3).
Figure 2. Grandao
Resource Model
Figure 3. Cross Section through Grandao
Resource Model
At the NOA Deposit, mineralisation is hosted in a steep dipping,
NW trending tabular dyke 5m-10m in true width. The Mineral Resource
Estimate is based on results from 9 reverse circulation drill holes
completed by Savannah in 2017. The Deposit outcrops over a strike
length of approximately 400m and remains open along strike and at
depth (Figure 4-5).
Figure 4. NOA Resource
Model
Figure 5. Cross Section through NOA Resource
Model
The Mineral Resource Estimate has been classified as an Inferred
Mineral Resource Estimate in accordance with the JORC Code, 2012
Edition and are shown in Table 1.
Table 1. Grandao and
NOA Deposits Inferred Mineral Resource Estimate
(above 0.5% Li2O cut-off grade)
Deposit
|
Tonnes
|
Li2O
|
Fe2O3
|
Li2O
|
|
Mt
|
%
|
%
|
Tonnes
|
Grandao
|
5.5
|
1.04
|
1.2
|
56,500
|
NOA
|
0.5
|
1.23
|
1.3
|
5,600
|
RESOURCE SUMMARY – GRANDAO AND NOA LITHIUM
DEPOSITS
Geology
At Mina do Barroso, lithium mineralisation occurs predominantly in
the form of spodumene-bearing pegmatites, which are hosted in
metapelitic and mica schists, and occasionally carbonate schists of
upper Ordovician to lower Devonian age. The main Grandao pegmatite
is a flat-lying, tabular zone defined over an area of 400m
north-south and 330m east-west and varies in thickness from
10m-50m. It is very close to surface and is visible in outcrop over
a significant area. A lower zone of mineralisation is also present
at Grandao, hosted in what is interpreted to be a steep-dipping,
tabular pegmatite dyke 15m-20m in true width. The geometry is not
well defined due to the currently sparse drilling (Figure
4).
Figure 6. Grandao
Geological Model
At the NOA Deposit, the host pegmatite is a steep dipping,
northwest trending dyke, which is 5-10m in true width. It has been
mapped in outcrop over much of the interpreted 400m strike length
of the Mineral Resource Estimate.
Figure 7. NOA
Geological Model
At the Project, lithium is present in most aplite compositions
and laboratory test work confirms that the lithium is almost
exclusively within spodumene. Distinct lithium grade zonation
occurs within the pegmatites, with weakly mineralised zones often
evident at the margins of the dykes. Minor xenoliths and inliers of
schist are observed on occasions.
The weathering profile comprises a shallow, surficial zone of
weak to moderate oxidation, particularly of the schistose country
rock. A zone of deeper weathering exists on the western side of the
Grandao Deposit with moderate oxidation to a depth of up to
50m.
Drilling
A total of 40 RC holes define the Grandao Inferred Mineral Resource
Estimate. The holes were drilled on an approximate grid spacing of
40m-60m. All holes were drilled by Savannah in 2017.
The NOA Deposit is defined by 9 RC holes. In the southeast
portion of the deposit, holes are drilled at 30m spacings on 50-60m
spaced cross sections. The northwest portion of the deposit is
defined by single drill holes on 60-80m spaced sections.
Drill collar locations are recorded in Universal Traverse
Mercator (“UTM”) coordinates using hand-held GPS, with elevations
adjusted to a regional topographic Digital Terrain Model (“DTM”).
All Savannah drilling has been down-hole surveyed using a
gyroscopic tool.
Sampling and Sub-Sampling
Techniques
For the Savannah drilling, a face-sampling hammer was used with
samples collected at 1m intervals from pegmatite zones with
composite sampling of typically 4m in the surrounding schists. The
1m samples were collected through a rig-mounted rotary splitter and
were 4kg-6kg in weight. The 4m composites were collected by spear
sampling of the 1m intervals. Samples were weighed to assess the
sample recovery which was determined to be satisfactory.
Sample Analysis
Method
For all Savannah drilling, whole samples were crushed then riffle
split to produce a 250g split for pulverizing and analysis.
The samples were analysed using ALS laboratories ME-MS89L Super
Trace method which combines a sodium peroxide fusion with ICP-MS
analysis and a multi-element suite was analysed.
QAQC protocols were in place for the drilling programmes and
included the used of standards and field duplicates. The data has
confirmed the quality of the sampling and assaying for use in
Mineral Resource estimation.
Estimation
Methodology
For the Grandao Mineral Resource Estimate, a Surpac block model was
constructed with block sizes of 20m (EW) by 10m (NS) by 5m
(elevation) with sub-celling to 5m by 2.5m by 1.25m. The typical
drill hole spacing is 40m-60m.
For the NOA Mineral Resource Estimate, block size used was 20m
(EW) by 5m (NS) by 5m (elevation) with sub-celling to 5m by 1.25m
by 1.25m.
Interpretation of the pegmatite dykes was completed using
detailed geological logging and Fe geochemistry. Wireframes of the
pegmatites were prepared and within those the sample data was
extracted and analysed. A clear break in the grade distribution
occurs at 0.5% Li2O and this grade threshold was used to
prepare the internal grade domains for estimation. Zones of
unmineralised schist within the pegmatite body were selectively
wireframed and excluded from the estimate.
At Grandao, pegmatite and mineralisation domains were
extrapolated up to 40m horizontally from the drill hole
intersections. At NOA, wireframes were extended 40m-60m down dip
from intersections and for 40m along strike.
Sample data was composited into 1m intervals then block model
grades estimated using ordinary kriging (OK) grade interpolation at
Grandao and inverse distance squared (ID2) grade interpolation at
NOA. A first pass search range of 50m was used and oriented to
match the dip and strike of the mineralisation. A minimum of 10
samples and a maximum of 24 samples were used to estimate each
block. The majority of the Mineral Resource Estimate (63% Grandao,
61% NOA) was estimated in the first pass with expanded search radii
of 100m and 200m used for the blocks not estimated in the first
pass. No high-grade cuts were applied to the estimate.
Iron within the pegmatites is uniformly low, with a mean
Fe2O3 grade of 1.2% at Grandao and 1.3% at
NOA. Other similar deposits have reported that a large proportion
of the assayed iron is due to contamination from the abrasion of
steel drilling and sample preparation equipment and this will be
investigated as part of ongoing studies at the project.
Bulk density determinations (helium pycnometer) were carried out
on 87 sample pulps. Bulk density values applied to the estimates
were 2.5t/m3 for oxide lithologies, 2.7t/m3
for unoxidized pegmatite and 2.8t/m3 for unoxidized
schist.
Mineral Resource
Classification
The Mineral Resource Estimate was classified in accordance with the
Australasian Code for the Reporting of Exploration Results, Mineral
Resources and Ore Reserves (JORC, 2012).
The main pegmatite dyke at Grandao has generally been defined by
40m to 60m spaced drill holes. The majority of holes have
consistently intersected pegmatite, with the majority intersecting
resource grade Li2O mineralisation and the continuity of
lithium mineralisation is good. The deep dyke has been delineated
by only three drill holes. Detailed collar and topographic surveys
were not available for the deposit and until these are received the
deposit has been classified as an Inferred Mineral Resource
Estimate.
The NOA Deposit has been drilled at 30m to 80m hole spacings.
All holes have intersected resource grade lithium mineralisation
but due to the broad hole spacing and small number of
intersections, the Deposit has been classified as an Inferred
Mineral Resource Estimate.
The main shallow pegmatite at Grandao lies entirely above 90m
vertical depth. The deep pegmatite has been reported to a depth of
260m vertical. The NOA mineralisation has been reported to a
maximum vertical depth of 90m.
Cut-off Grades
The shallow, outcropping nature of both deposits and the flat
lying, shallow nature of the Grandao pegmatite suggests good
potential for open pit mining if sufficient resources can be
delineated to consider a mining operation. The lower pegmatite at
Grandao has favourable geometry and thickness to consider low-cost
underground mining. As such, the Mineral Resource Estimate has been
reported at a 0.5% Li2O lower cut-off grade to reflect
assumed exploitation by low cost mining methods.
Metallurgy
Metallurgical test work has been conducted by Savannah on
representative mineralisation at Mina do Barroso. The work was
completed by Nagrom Metallurgical in Australia and confirmed that
high-grade lithium, low grade iron concentrate can be generated
from the mineralisation using conventional processing technology.
Microscopy confirmed that the concentrate was almost entirely
spodumene.
Modifying Factors
No modifying factors were applied to the reported Mineral Resource
Estimate. Parameters reflecting mining dilution, ore loss and
metallurgical recoveries will be considered during the any future
mining evaluation of the project.
Exploration Target
During its first six months of exploration, Savannah has defined a
Mineral Resource Estimate from three deposits in the Mina do
Barroso Project area. All three deposits remain open and untested
by drilling either down dip or along strike of the defined Mineral
Resource Estimate and there is excellent potential to extend the
deposits with further drilling. In addition, there are numerous
other outcropping pegmatite dykes that require drill testing to
determine if they are also lithium bearing.
Savannah has been drilling at Mina do Barroso since mid-2017 and
ongoing programmes for 2018 have commenced which are designed to
test for extensions of the defined deposits and to test other
outcropping pegmatite targets in the Project area. Infill drilling
to increase the confidence in the reported Inferred Mineral
Resource Estimate is also being planned.
To quantify the potential of the Project beyond the currently
defined Inferred Mineral Resource Estimate, an initial Exploration
Target* for the Grandao and Reservatorio Deposits of 8-12Mt at 1.0%
to 1.2% Li₂O has been defined. This gives a project target
(including Mineral Resource Estimate) of 17-21Mt at 1.0-1.2%
Li₂O.
Table 2. Exploration Targets for Mina do
Barroso Project
Deposit |
|
Tonnage
Range (Mt) |
Li2O
% |
|
Lower |
Upper |
|
Reservatorio |
|
|
|
|
Bottom of Inferred to 200m Vertical
Depth |
|
5.0 |
7.0 |
1.0-1.2% |
Grandao |
|
|
|
|
50% Expansion of Upper Pegmatite |
|
2.0 |
3.0 |
1.0-1.2% |
100% Expansion of
Lower Pegmatite |
|
1.0 |
2.0 |
1.0-1.2% |
Total Mina do
Barroso Exploration Target |
|
8.0 |
12.0 |
1.0-1.2% |
*Cautionary Statement: The potential quantity and grade of the
Exploration Targets is conceptual in nature, there has been
insufficient exploration work to estimate a mineral resource and it
is uncertain if further exploration will result in defining a
mineral resource.
Reservatorio Exploration
Target
A Mineral Resource Estimate was completed for the Reservatorio
Deposit in December 2017. It was modelled and estimated for the
full extent of the SAV drilling and the Inferred Mineral Resource
Estimate was extended between 40m and 100m down dip from the
deepest drill holes.
There is no information to suggest that the pegmatite and
lithium mineralisation does not continue with the same
characteristics and grade as the drilled portion. As a result,
beneath the Inferred Mineral Resource Estimate boundary, a
wireframe model was created, assuming continuation of the
mineralisation down-dip to 200m below surface. Applying a density
of 2.6t/m3 as used in the Reservatorio Inferred Mineral Resource
Estimate, and assuming the same lithium grade observed in the
drilled portion, the Exploration Target has been defined as 5 Mt to
7 Mt at a grade of 1.0% to 1.2% Li2O.
Grandao Exploration
Target
An Inferred Mineral Resource Estimate was completed for the Grandao
Deposit in February 2018. It was modelled and estimated for the
area drilled in detail by SAV. The Inferred Mineral Resource
Estimate was extended between 20m and 40m along strike from drilled
area.
The shallow pegmatite appears to be closed off by drilling to
the northeast and to the southeast. To the west and northwest, the
mineralisation remains open and untested. To the south some sparse
drilling has confirmed the presence of mineralised pegmatite for up
to 150m from the Mineral Resource Estimate boundary and the limits
of the mineralisation have not been found. There is no information
to suggest that the pegmatite and lithium mineralisation does not
continue to the west and northwest with the same characteristics
and grade as the drilled portion.
The Exploration Target for the shallow pegmatite is considered
to be at least 50% of the defined Mineral Resource Estimate for
that portion of the deposit so the Exploration Target has been
defined as 2 Mt to 3 Mt at a grade of 1.0% to 1.2%
Li2O.
The deep pegmatite has been intersected in only three holes
which have recorded thick, high grade mineralisation. The
mineralisation is open in all directions and the Exploration Target
has been defined as a 100% increase on the defined Mineral Resource
Estimate which gives a Exploration Target of 1 Mt to 2 Mt at a
grade of 1.0% to 1.2% Li2O.
Competent Person and Regulatory
Information
The information in this announcement that relates to exploration
results is based upon information compiled by Mr Dale Ferguson,
Technical Director of Savannah Resources Limited. Mr Ferguson is a
Member of the Australian Institute of Mining and Metallurgy
(AusIMM) and has sufficient experience which is relevant to the
style of mineralisation and type of deposit under consideration and
to the activity which he is undertaking to qualify as a Competent
Person as defined in the December 2012 edition of the “Australasian
Code for Reporting of Exploration Results, Mineral Resources and
Ore Reserves” (JORC Code). Mr Ferguson consents to the inclusion in
the report of the matters based upon the information in the form
and context in which it appears.
The Information in this report that relates to Mineral Resources
and Exploration Targets is based on information compiled by Mr Paul
Payne, a Competent Person who is a Fellow of the Australasian
Institute of Mining and Metallurgy. Mr Payne is a full-time
employee of Payne Geological Services. Mr Payne has sufficient
experience that is relevant to the style of mineralisation and type
of deposit under consideration and to the activity being undertaken
to qualify as a Competent Person as defined in the 2012 Edition of
the “Australasian Code for Reporting of Exploration Results,
Mineral Resources and Ore Reserves”. Mr Payne consents to the
inclusion in the report of the matters based on his information in
the form and context in which it appears.
This announcement contains inside information for the purposes
of Article 7 of Regulation (EU) 596/2014.
CONTACT US
|
For further information please visit www.savannahresources.com or contact:
|
David Archer
Chief Executive Officer
|
Savannah Resources plc
|
Tel: +44 20 7117 2489
|
David Hignell / Gerry Beaney (Nominated Adviser)
|
Northland Capital Partners Ltd
|
Tel: +44 20 3861 6625
|
Christopher Raggett / Emily Morris
(Joint Broker)
|
finnCap Ltd
|
Tel: +44 20 7220 0500
|
Jon Belliss
(Joint Broker)
|
Beaufort Securities Ltd
|
Tel: +44 20 7382 8300
|
Charlotte Page / Lottie Wadham
(Financial PR)
|
St Brides Partners Ltd
|
Tel: +44 20 7236 1177
|
About Savannah
We are a diversified resources group (AIM: SAV and SWB: SAV) with a
portfolio of energy metals projects - lithium in Portugal and
copper in Oman - together with the world-class Mutamba Heavy
Mineral Sands Project in Mozambique, which is being developed in a
consortium with the global major Rio Tinto. We are committed to
serving the interests of our shareholders and to delivering
outcomes that will improve the lives of our staff and the
communities we work with.
The group is listed and regulated on AIM and the Company’s
ordinary shares are also available on the Börse Stuttgart (SWB)
under the ticker “SAV”
Please refer to the Savannah Resources website for the full RNS,
www.Savannahresources.com
|