Thor Explorations Announces Updated Mineral Resource Estimate at the Douta Gold Project, Senegal
Thor Explorations Announces Updated Mineral
Resource Estimate at the Douta Gold Project,
Senegal
NOT FOR DISSEMINATION IN THE UNITED STATES OR FOR
DISTRIBUTION TO U.S. WIRE SERVICES
Vancouver, British Columbia--(Newsfile Corp. - March 20, 2023) - Thor Explorations Ltd. (TSXV: THX)
(AIM: THX) ("Thor" or the "Company") is pleased to announce the results of an updated Mineral
Resource Estimate (the "Douta Resource" or "2023 MRE") prepared in accordance with National
Instrument 43-101
Standards of Disclosure for Mineral Projects
("NI 43-101") for the Douta Gold Project
in Senegal.
Highlights
Total Douta Resource of approximately 1.78 million ounces ("Moz") of gold ("Au"), an increase of
144% in total resource as compared with the 2022 maiden mineral resource estimate declared for
Douta in November 2021
Douta Resource constrained within optimised pit shells and comprised of:
an initial Indicated Mineral Resource of 20.2 million tonnes ("Mt") grading 1.3 grammes per
tonne ("g/t") Au for 874,900 oz Au; and
Inferred Mineral Resource of 24.1 Mt grading 1.2 g/t Au for 909,400 oz Au
2023 MRE supported by a total of 64,567 metres of drilling
Updated Douta Resource encompasses the Makosa, Makosa Tail and the recently discovered
Sambara prospects, all of which remain open along strike and down dip
Drilling is ongoing on the above prospects with a further 40,000 metre drilling program to be
completed in 2023, consisting of diamond drilling and reverse circulation drilling. Mineralisation
remains open along strike between the known prospects with further growth potential along 20
kilometres of under-explored prospective strike length covered by the Douta exploration permit
Segun Lawson, President & CEO, stated:
"This is an excellent milestone in the progress of the Douta Project. The 2023 MRE has more than
doubled the contained gold within the Douta permit to over 1.7 million ounces, with the indicated
component of the resource alone exceeding 870,000 ounces of gold compared to the maiden inferred
resource of 730,000 ounces. In addition, there are a further 909,000 ounces of inferred resources
within the optimised pit shells that we intend to convert to indicated classification with additional infill
drilling which forms part of our ongoing 40,000 metre program. This updated resource base provides
for a solid foundation for more advanced studies on the pathway to developing Thor's second
operating gold mine in West Africa."
"We are now focussing our exploration efforts towards expanding the resource along the prospective
corridor that runs along the full 30km length of our exploration licence. Priority will be given to
extensional drilling at Makosa, Maka, Mansa and the newly discovered Sambara prospects."
Introduction
The Douta Gold Project is located within the Kéniéba inlier, in eastern Senegal, and comprises the
northeast trending gold exploration permit, E02038 that covers an area of 58 square kilometres ("km
2
").
Thor, through its wholly owned subsidiary African Star Resources Incorporated ("African Star"), has a
70% economic interest in partnership with the permit holder International Mining Company SARL
("IMC"). IMC has a 30% free carried interest in its development until the announcement by Thor of a
Probable Reserve.
The Douta licence is strategically positioned 4km east of the deposits Massawa North and Massawa
Central deposits which form part of the world class Sabadola-Massawa Project that is owned by
Endeavour Mining (Figure 1). The Makabingui deposit, belonging to Bassari Resources Ltd, is located
immediately to the east of the northern portion of E02038.
Summary of the 2023 MRE
The 2023 MRE encompasses the Makosa, Makosa Tail and Sambara zones, which are collectively
named the Douta Resource.
The MRE has been estimated by an independent consultant and is reported at a cut-off grade of 0.5 g/t
Au within optimised shells using a gold price of US$2,000.
Classification
Tonnes
(Mt)
Grade
(g/t Au)
Contained Gold
(k ounces)
Thor Interest
Indicated
21.2
1.3
875
70%
Inferred
24.1
1.2
909
70%
Table 1: Douta Gold Project Total Classified Mineral Resource Estimate Summary, March 2023
(reported at cut-off grade of 0.5 g/t Au)
Open Pit Mineral Resources are reported in situ at a cut-off grade of 0.50 g/t Au. An optimised
Whittle shell (US$2,000) was used to constrain the resources.
The Mineral Resource is considered to have reasonable prospects for economic extraction by
open pit mining methods above a 0.50 g/t Au and within an optimised pit shell.
Cut-off grade varied from 0.45 g/t to 0.48 g/t in a pit shell based on mining costs, metallurgical
recovery, milling costs and G&A costs.
Resource is reported as in-situ and no metallurgical or mining recovery factors have been
applied.
Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability.
Totals may not add exactly due to rounding.
The statement used the terminology, definitions and guidelines given in the CIM Standards on
Mineral resources and Mineral Reserves (May 2014) as required by NI 43-101.
Bulk density is assigned according to weathering profile with a weighted average of 2.78.
The resource estimate was prepared by Mr. Kevin Selingue, Principal Geologist of MineralMind,
Australia in accordance with NI 43-101. Mr. Selingue is an independent qualified person ("QP")
as defined by NI 43-101.
Mineral Resource Estimate
The MRE, as detailed in Table 2, has been estimated by an independent consultant and is reported at a
cut-off grade of 0.5 g/t Au within optimised shells using a gold price of US$2,000.
Area
Classification
Tonnes
Grade
(g/t Au)
Contained Gold
(ounces)
Thor Interest
Makosa
Indicated
15,210,000
1.22
598,000
70%
Makosa
Inferred
18,490,000
1.10
654,600
70%
Makosa Tail
Indicated
4,610,000
1.73
256,800
70%
Makosa Tail
Inferred
3,170,000
1.68
171,300
70%
Sambara
Indicated
360,000
1.75
20,100
70%
Sambara
Inferred
2,427,000
1.07
83,500
70%
Total
Indicated
20,180,000
1.34
874,900
70%
Total
Inferred
24,090,000
1.17
909,400
70%
Table 2: Douta Gold Project Mineral Resource Estimate by Area, March 2023
(reported at cut-off grade of 0.5 g/t Au)
Open Pit Mineral Resources are reported in situ at a cut-off grade of 0.50 g/t Au. An optimised
Whittle shell (US$2,000) was used to constrain the resources.
The Mineral Resource is considered to have reasonable prospects for economic extraction by
open pit mining methods above a 0.50 g/t Au and within an optimised pit shell.
Cut-off grade varied from 0.45 g/t to 0.48 g/t in a pit shell based on mining costs, metallurgical
recovery, milling costs and G&A costs.
Metallurgical and mining recovery factors not applied.
Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability.
Totals may not add exactly due to rounding.
The statement used the terminology, definitions and guidelines given in the CIM Standards on
Mineral resources and Mineral Reserves (May 2014) as required by NI 43-101.
Bulk density is assigned according to weathering profile with a weighted average of 2.78.
The resource estimate was prepared by Mr. Kevin Selingue, Principal Geologist of MineralMind,
Australia in accordance with NI 43-101. Mr. Selingue is an independent qualified person ("QP")
as defined by NI 43-101.
Drilling
The MRE is based on data obtained from a total of 64,567m of drilling consisting of 1,937m of diamond
drilling and 62,630m of Reverse Circulation ("RC") drilling which have been used to generate the
updated MRE. RC drilling was carried out by Sengold (2020-2023), while historic diamond drilling was
carried out by International Drilling Company (2017), Sendrill Consulting (2018) and ADS (2012).
Sample Analysis and Database
Drilling has been almost exclusively sampled on 1m intervals with the primary laboratory for analysis
being ALS Global's laboratory in Bamako, Mali. Split samples ranging in weight from 0.5 kilograms
("kg") to 3.5kg, with an average of 2.3kg were collected for analysis. After the sample preparation a fire
assay with an atomic absorption finish on a 50 grammes ("g") subsample of the pulp (AA26), was
completed. Umpire samples were submitted to the MSA laboratory in Abidjan.
Standard QA/QC protocols were followed with inserts of certified standards, blanks and duplicates
representing approximately 10% of all analyses.
The Company's database is maintained internally with independent audits carried out by Cube
Consulting (Perth) on request.
Figure 1: Douta Project Location Map
To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/7003/159064_56ccef66b491b8c7_002full.jpg
Estimation Parameters
A four-pass Inverse Distance grade estimation was carried out within hard geological boundaries
defined by a numerical models based on a nominal modelling grade cut off of 0.65 g/t Au. Ordinary
Kriging has been used to validate the Inverse Distance estimation results.
Separate numerical models, using a 0.65 g/t Au cut off were generated for Makosa Tail, Makosa North
and East and Sambara.
A weathering model was developed so bulk densities could be assigned according to weathering state.
The tonnage factor in the block models was based on 188 bulk density measurements and determined
by assigning the averaged bulk densities to the following material types:
2.76 t/m3 for Fresh (FRS),
2.70 t/m3 for weakly oxidized (WOX),
2.60 t/m3 for moderately oxidized (MOX), and
2.50 t/m3 for strongly oxidized (SOX).
At this stage of the project, it is appropriate that blocks within the Makosa mineralised zones have the
same average bulk densities as the blocks within the Makosa waste zones.
Exploratory Data Analysis and Top Cut Selection
Prior to selecting the composite length, the average sample length was determined. The majority (91%)
of the samples are 1.0m long, thus a 1m composite length was adopted.
Statistical analysis was completed on assay values composited to 1m and extracted from within the
mineralised zone domains for the two prospect areas, with a top cut (cap) being selected to reduce the
influence of any 'outlier' high grades.
Globally, a total of 4,594 composites were included in the database for top capping analysis. At Makosa
Main, nine (9) composite gold values that exceeded 15 g/t were reduced to 15 g/t. At Makosa Tail,
eleven (11) composite gold values that exceeded 15 g/t were reduced to 15g /t. At Sambara, two (2)
composite gold values that exceeded 15 g/t were reduced to 15 g/t. Gold composite values below were
unchanged. The effect of the application of the top cuts is summarised in Table 3.
At Makosa, the top capping reduced the average mean grade from 1.29 g/t Au to 1.23 g/t Au.
At
Makosa Tail, the top capping reduced the average mean grade from 1.69 g/t Au to 1.57 g/t Au. At
Sambara, the top capping reduced the average mean grade from 1.9 g/t Au to 1.81 g/t Au.
Domain
No of Composites
Maximum Au (g/t)
Mean Au (g/t)
Top Cut Au (g/t)
Capped Mean Au
(g/t)
No of Composites
affected
% Metal
Makosa
3,346
54.5
1.29
15
1.23
9
-5%
Makosa Tail
1,079
36.18
1.69
15
1.57
11
-7%
Sambara
169
21.12
1.90
15
1.81
2
-5%
Total
4,594
54.5
1.74
1.62
22
-5%
Table 3: Composite statistics and effect of top cut on contained metal
Estimation Methodology
Variography was carried out on each combined domain with the appropriate parameters used to
estimate the gold grade using Inverse Distance (ID). Due to the difference in orientation between
Makosa Tail, Makosa/Makosa North and Sambara three separate block models were created to better
align blocks with the orientation of the lode systems.
Block estimation used a five-pass strategy with the number of required samples with 1 to 5 for pass 1, 2
to 10 for pass 2, 2 to 20 for pass 3, 4 and 5, and search distance increased for each estimation pass.
Classification
Drill hole density ranges from 50m to 200m spaced sections with spacing between holes on-section
typically 30m (Figure 2).
The sample population within the 0.2 g/t grade shell indicates a good grade continuity, superior to most
orogenic gold deposits.
Classification is based on parameters extracted from the sample variograms.
The classification as 49% indicated and 51% inferred is considered appropriate for the current level of
understanding and development of the Mineral Resource.
Mineral Resource Constraints
To test the reasonable prospects for eventual economic extraction, the 2023 MRE is constrained by an
optimised pit shell (revenue factor of 1) defined by the parameters shown in Table 4.
A cross-section showing the pit shell in relation to the mineral resource at Makosa Tail is illustrated in
Figure 3.
Parameter
Unit
SOX
Strongly oxidised: 4% of the resource
45
degrees
MOX
Medium oxidised: 6% of the resource
45
degrees
WOX
Weakly oxidised: 4% of the resource
50
degrees
Fresh
Fresh Rock and sulphides: 86% of the resource
58
degrees
Mining Cost
- Load and Haul
US$1.2/t @ surface, increase $0.1/t per 5m bench
1.2
$/t
D&B - SOX
2.60 Total cost $/t
2.6
$/t
D&B - MOX/WOX
3.10 Total cost $/t
3.1
$/t
D&B - Fresh
4.00 Total cost $/t
4
$/t
Total
Mining Recovery
95
%
Mining Dilution
5
%
Processing Cost
- Variable Cost
power, reagents, consumables, direct labour costs
16
$/t ore
- G&A + overheads
5.5
$/t ore
- Grade Control
blast hole sampling/gc program
0.5
$/t ore
- Ore Mining
Included in Mining Cost
$/t ore
Total
22
$/t
Process Recovery
SOX
90
%
MOX
90
%
WOX
90
%
Fresh
88
%
Product Sell Price
Multiple gold prices to be run
$2,000
US$/oz
Sell Price
$64.30
gram
Discount Rate
8
%
Mill Limit
2.5
Mill Mt/pa
Table 4: Open Pit Optimisation Parameters
Metallurgical Factors
Thor has submitted metallurgical samples to ALS (Perth) and preliminary recovery results indicate that
oxide material may be recovered by normal gravity/CIL methods whereas the fresh material is refractory
to partially refractory and may be recovered by either Biological Oxidation (BIOX) or Pressure Oxidation
(POX) methods. Ongoing metallurgical test work is focussed on achieving the optimal operational flow
sheet for the fresh material.
The initial metallurgical results at Makosa are comparable to those reported from initial test work at the
Massawa deposit which is located 4km to the west and which is owned by Endeavour Mining. Following
exhaustive metallurgical testing the optimal laboratory flow sheet for Massawa achieved recoveries of
88% for fresh (refractory to partially refractory) using a BIOX processing route and 90% for oxide to
transitional.
Until a representative number of samples has been fully tested using optimal recovery techniques Thor
has adopted similar recovery factors used at Massawa.
This is considered appropriate for the current level of classification and understanding of the Mineral
Resource.
Figure 2: Drillhole Location Plan
To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/7003/159064_56ccef66b491b8c7_003full.jpg
Figure 3: Cross Section through Makosa Tail
To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/7003/159064_56ccef66b491b8c7_004full.jpg
Environmental Factors
No impediments with respect to reserves, parks or other areas of significance have been identified on
the project area. The Douta exploration licence consists of a modified environment as a result of human
activities including harvesting forest flora and burning vegetation as part of sporadic and unregulated
historic artisanal mining activity. There are no settlements within the licence boundary.
Thor abide by the Senegal 2016 Mining Code, which introduced an obligation for mining title holders to
contribute annually to a local development fund in the amount of 0.5% of sales, minus annual fees. Under
the 2016 Code, mining projects require a prior environmental impact assessment, to be approved by the
Directorate of the Environment and Classified Establishments.
Initial environmental baseline information within the Douta exploration licence has included both dry and
wet season ecology surveys that were carried out in May 2021 and November 2022 by Senegal-based
Synergie Afrique. Further ground and surface water quality monitoring has commenced within the
exploration permit in November 2022 and will continue with quarterly monitoring. The surveys will form
part of the overall Environment and Social Impact Assessment ("ESIA") which is expected to be
completed within 12 months.
Ongoing Exploration
Thor intends to progress the Makosa Resource expansion drilling together with parallel workstreams
including detailed metallurgical sampling and testing, environmental and social baseline monitoring as
part of an Environmental and Social Impact Assessment, geotechnical and hydrological studies.
The main resource expansion priorities are:
1
.
Infill and resource definition drilling to convert inferred to indicated classification.
2
.
Continued drilling to increase the overall resource base through extensional drilling along the
prospective corridor.
About Thor
Thor Explorations Ltd. is a Canadian, West African focussed mineral gold producer listed on both the
TSX Venture Exchange (TSXV: THX) and AIM Market of the London Stock Exchange (AIM: THX). Thor
produced 98,000 ounces from its 100% owned Segilola Gold Mine located in Osun State of Nigeria and
a 70% interest in the Douta Gold Project located in south-eastern Senegal. Thor trades on the TSX
Venture Exchange under the symbol "THX".
THOR EXPLORATIONS LTD.
Segun Lawson
President & CEO
Qualified Person
The above information relating to the resource estimate has been prepared by Mr. Kevin Selingue,
Principal Geologist of MineralMind, Australia in accordance with NI 43-101, and is responsible for this
MRE. Mr. Selingue is an independent qualified person ("QP") as defined by NI 43-101 and is a qualified
person under the AIM Rules and has reviewed and approves the content of this news release.
The information relating to exploration results has been prepared under the supervision of Alfred Gillman
(Fellow AusIMM, CP), who is designated as a "qualified person" under National Instrument 43-101 and
the AIM Rules and has reviewed and approves the content of this news release. He has also reviewed
QA/QC, sampling, analytical and test data underlying the information.