Mr. Marc LeVier reports
GREAT WESTERN MINERALS SIGNIFICANTLY UPGRADES MINERAL RESOURCE ESTIMATE FOR STEENKAMPSKRAAL RARE EARTH PROJECT
Great Western Minerals Group Ltd.'s new National Instrument 43-101-compliant technical report and mineral resource estimate for the Steenkampskraal rare earth project show a significant increase of tonnes in the indicated category and the addition of newly defined tonnes in the measured category. Over all, the size of the resource has increased compared with the company's previously released mineral resource estimate dated December, 2012.
Highlights of the MRE are as follows (resource estimates based on 1-per-cent cut-off grade):
- 16,600 tonnes of total rare earth oxides, including yttrium oxide, from the in situ resource now in the measured category;
- 67,000 tonnes of TREO in the in situ indicated category, an increase of 38,200 tonnes;
- Overall increase of 171 per cent, or 54,800 tonnes of TREO, in the in situ and tailings measured and indicated categories to 86,900 tonnes;
- All tailings now report to the indicated category for a total of 46,000 tonnes of surface material hosting 3,300 tonnes of TREO at a lower grade of 7.18 per cent compared with the December, 2012, MRE, due to the combination of the two historic tailings dams and addition of low-radioactivity materials recovered during site cleanup.
Company president and chief executive officer Marc LeVier stated: "A significant increase in assay data from core drilling and underground sampling at SKK during the last year has provided input for a new resource estimate. The results of the MRE show an increase of total rare earth oxides including yttrium oxide bringing the total in situ and tailings indicated and measured resource to 86,900 tonnes TREO. We also saw a substantial upgrade of the previous inferred resource component to the indicated category or better and increased the overall tonnes of TREO that are candidates for conversion to formal reserves."
The new MRE on the SKK project, which has been prepared by Snowden Mining Industry Consultants Inc., is dated effective Oct. 31, 2013, and will be filed and available under the company's SEDAR profile within 45 days.
For its new MRE, the company provided the additional information shown in the table beyond that utilized in the mineral resource estimate dated Dec. 31, 2012. This additional information contributed to increasing the data density and the extent of mineralization both along strike and down dip.
COMPARISON OF DATA INPUT FOR RECENT MINERAL RESOURCE ESTIMATES
Data December, 2012, October, 2013,
comparison MRE and PEA MRE Difference
Data cut-off Oct. 31, 2012 Aug. 31, 2013
Drill holes (resource, MET
and EXP) 145 232 87
Drilling metreage 16,270.55 27,977.00 11,726.45
Number of core samples 789 1,079 290
Number of blank holes 27 69 42
Number of mineralized
intersections 96 147 51
Average reef true thickness
(m) 1.04 0.96 -0.08
Number of UG channels 71 102 31
Number of channel plus panel
samples 223 277 54
Number of tailings samples 270 290 20
Assay plus
calculated All assay
Data quality grades grades
Infill Infill
incomplete; complete; six
four domains; domains;
Data density not bounded bounded
The results of the new MRE are shown in the second table and also in the table appended to the end of the document.
RESULTS OF OCTOBER, 2013, MRE COMPARED WITH DECEMBER, 2012, MRE
Report December, 2012, MRE
Mineraliz. TREO
Area Class (tonnes) Item (tonnes)
In situ mine Measured 0 Metal tonnes 0
Grade (%) 0
Indicated 71,500 Metal tonnes 16,400
Grade (%) 22.97
Inferred 95,800 Metal tonnes 16,400
Grade (%) 17.13
In situ Indicated
exploration 68,200 Metal tonnes 12,400
Grade (%) 18.12
Inferred 181,000 Metal tonnes 25,600
Grade (%) 14.17
All in situ Subtotal
Measured 0 Metal tonnes 0
Grade (%) 0
All in situ Subtotal
Indicated 139,700 Metal tonnes 28,800
Grade (%) 20.60
All in situ Subtotal
Inferred 276,800 Metal tonnes 42,000
Grade (%) 15.19
Combined in Measured +
situ indicated 139,700 Metal tonnes 28,800
Grade (%) 20.60
Upper tailings Indicated 8,000 Metal tonnes 750
Grade (%) 9.3
Inferred 1,200 Metal tonnes 100
Grade (%) 7.48
Lower tailings Indicated 28,600 Metal tonnes 2,500
Grade (%) 8.84
New combined Indicated
tailings 0 Metal tonnes 0
Grade (%) 0
Total SKK Measured 0 Metal tonnes 0
Grade (%) 0
Total SKK Indicated 176,300 Metal tonnes 32,100
Grade (%) 18.2
Total SKK Inferred 278,000 Metal tonnes 42,100
Grade (%) 15.16
Total SKK Measured +
indicated 176,300 Metal tonnes 32,100
Grade (%) 18.2
Report October, 2013, MRE
Mineraliz. TREO
Area Class (tonnes) Item (tonnes)
In situ mine Measured 85,000 Metal tonnes 16,600
Grade (%) 19.54
Indicated 154,000 Metal tonnes 22,800
Grade (%) 14.79
Inferred 20,000 Metal tonnes 2,500
Grade (%) 12.77
In situ Indicated
exploration 320,000 Metal tonnes 44,100
Grade (%) 13.80
Inferred 40,000 Metal tonnes 3,700
Grade (%) 9.30
All in situ Subtotal
Measured 85,000 Metal tonnes 16,600
Grade (%) 19.54
All in situ Subtotal
Indicated 474,000 Metal tonnes 67,000
Grade (%) 14.12
All in situ Subtotal
Inferred 60,000 Metal tonnes 6,200
Grade (%) 10.46
Combined in Measured
situ Indicated 559,000 Metal tonnes 83,600
Grade (%) 14.95
Upper tailings Indicated 0 Metal tonnes 0
Grade (%) 0
Inferred 0 Metal tonnes 0
Grade (%) 0
Lower tailings Indicated 0 Metal tonnes 0
Grade (%) 0
New combined indicated
tailings 46,000 Metal tonnes 3,300
Grade (%) 7.18
Total SKK Measured 85,000 Metal tonnes 16,600
Grade (%) 19.54
Total SKK Indicated 520,000 Metal tonnes 70,300
Grade (%) 13.51
Total SKK Inferred 60,000 Metal tonnes 6,200
Grade (%) 10.46
Total SKK Measured +
indicated 605,000 Metal tonnes 86,900
Grade (%) 14.36
Report Difference (compared with December, 2012)
Mineraliz. Mineraliz. TREO TREO
Area Class (tonnes) (%) (tonnes) (%)
In situ mine Measured 85,000 16,600
19.54
Indicated 82,500 215 6,400 139
-8.18 64
Inferred -75,800 21 -13,900 15
-4.36 75
In situ Indicated
exploration 251,800 469 31,700 356
-4.32 76
Inferred -141,000 22 -21,900 14
-4.87 66
All in situ Subtotal
Measured 85,000 16,600
19.54
All in situ Subtotal
Indicated 334,300 339 38,200 233
-6.5 69
All in situ Subtotal
Inferred -216,800 15 -35,800 15
-4.74 69
Combined in Measured +
situ indicated 419,300 400 54,800 290
-5.66 73
Upper tailings Indicated -8,000 -100 0
0
Inferred -1,200 -100 0
0
Lower tailings Indicated -28,600 0 0 0
0 0
New combined Indicated
tailings 46,000 3,300
7.18
Total SKK Measured 85,000 16,600
19.54
Total SKK Indicated 343,700 295 38,200 219
-4.7 74
Total SKK Inferred -218,000 22 -35,900 15
-4.70 69
Total SKK Measured +
indicated 428,700 343 54,800 271
-3.8 79
Notes:
TREO refers to total rare earth oxides plus yttrium oxide. Grades for
in situ mine and exploration area for each resource category are as
reported from data mine modelling. Material tonnes were rounded to three
significant figures. Metal tonnes for TREO were rounded to nearest hundred
tonnes. For the October, 2013, MRE, grades were rounded to two decimal
places. Apparent errors may result due to rounding. The metal tonnes for
indicated and inferred totals were calculated by summing the metal tonnes
of each category in each area. The grades for indicated and inferred were
calculated by dividing the metal tonnes by the tonnage as reported by
data mine modelling. Resource estimates based on a cut-off of 1 per cent
TREO.
Geology and mineralization
The SKK mineralization consists of a narrow, shallow and irregular dipping (from 10 degrees to 60 degrees to the south) pinch-and-swell monazite vein, which is exposed at surface as an east-west-striking body. It has an average true thickness of about one metre, varying from less than two centimetres to just over 10 metres. The vein has been traced for a strike length of over 1,050 m and a known southerly down-dip extension of up to 150 m. The current MRE covers the full known strike length. The vein structure exhibits reasonably good lateral and vertical continuity, although the known mineralization is dissected by several fault structures of varying orientation, some of which have resulted in vertical and lateral displacements of one metre to tens of metres. Based on drilling results since 2011, which targeted shallow mineralization to a depth of approximately 150 m, mineralization currently is closed along strike in both directions and locally down dip. However, the interpretation in the structural geology model supports the potential for an extension of mineralization beyond the known east- and west-bounding faults.
Mineralogical investigations indicate that the vein is composed predominantly of the mineral monazite, which accounts for more than 91 per cent of total rare earth elements, with much lesser amounts of rare-earth-element-bearing allanite, thorite and xenotime. Alteration minerals are dominated by quartz, Fe-chlorite, magnetic Fe-oxide minerals, ilmenite and sulphides, including chalcopyrite, pyrite and galena. Vein material at SKK contains from 0.4 per cent to 46 per cent TREO, with the average grade typically dependent on the amount of diluting materials (such as quartz, feldspar, magnetite and sulphides) within the vein structure.
Exploration
The historic SKK mine has been partially rehabilitated by GWMG, and all three access levels and most of the old workings remain open to geological and geotechnical investigations. Evaluation and exploration work from September, 2011, to March, 2013, consisted of surveying, mapping and sampling 232 HQ and NQ surface drill holes totalling 27,977 m within the mine and adjacent exploration areas along strike and down dip and 102 underground channels within the historic mine workings. In addition, GWMG undertook evaluation drilling and sampling of the historic tailings dams. The rock dump has also been sampled, but was not included in this MRE.
Survey information, intercept thicknesses, lithological descriptions, density measurements, scintillometer readings and assay results for 1,626 samples were included in evaluation of mineral resources in this MRE. In comparison with the December, 2012, resource estimate, no calculated grades resulting from correlation of scintillometer data to assay results were utilized. Drill hole fence lines are oriented along down-dip lines perpendicular to strike on nominal 25 m to 50 m line spacing and 25 m collar centres. Of the 232 drill holes reviewed by Snowden, 69 did not intersect the zone of mineralization. These reported misses represent either drilling beyond the vein boundaries, local areas of non-mineralization within the vein system that may be related to pinch and swell, or to areas of structural displacement. Many of the misses were incurred during step-out drilling while searching for extensions of mineralization. Areas of mineralization bounded by faults with displacement were used to domain the zones of mineralization for greater control and confidence in the resource estimate methodology.
Quality assurance/quality control
The validated database for the MRE includes information on 1,079 core samples, 277 in situ underground samples and 290 tailings samples. Drill holes that did not contain assay data were included as they provided lithological information for the wire-frame modelling.
SGS Canada conducted the assay testing. Snowden examined the assay data of the blanks, certified reference materials and field duplicates to verify and assess the reliability of the overall assay data set and to assist in the determination of the robustness of the resource estimation. The addition of quality control samples for core, channel and tailings samples amounts to 19 per cent of overall rare earth assays. It was concluded by Snowden that the addition of reference material and blanks to the SKK sample batches was sufficiently adequate.
Modelling and estimation method
The mineralized zone wire frame representing the mineralized zone was generated using Leapfrog software after much verification work and guided by the available geological information. All of the assay intervals falling within the mineralized zone were composited to the dominant sample length of 0.5 m.
Establishment of block models and variography analysis
The interior of the mineralization wire frame was populated with blocks measuring 10 m by 10 m by 0.5 m using Datamine Studio version 3 software. Subblocking was used to provide for a more accurate volume determination, the smallest dimension for subblocks being 1.25 m by 1.25 m by 0.1 m. No rotation of blocks was applied as the strike and dip of the monazite was honoured through the small dimensions of subblocking.
Variograms were generated for each of the rare earth oxides, as well as yttrium, thorium and uranium, only using the assay data from the mineralized zone. Two structured (exponential first structures and spherical second structures) directional variograms were modelled. Downhole variograms were calculated and modelled to determine the nugget variance for the variogram models. The data occurring within the wireframes were combined for the domained zones to generate more robust variograms. All variograms were modelled on normal scores transformed data and back transformed prior to their use in grade estimation. The variograms showed well-developed structure and long ranges.
The block model comprises blocks of 10 m by 10 m by 0.5 m with subblocks down to 1.25 m by 1.25 m by 0.1 m in order to honour the attitude and shape of the mineralization.
Grade interpolation parameters
Block grades for yttrium, thorium and uranium were estimated using ordinary kriging. The six domains used for modelling were delineated based on the location of major faults and a small area of complexity characterized by bifurcation or interleaving of monazite veins. The zones were estimated separately and individual block models combined for classification.
TREO per cent, LREO per cent and HREO per cent values, which were calculated for reporting by combining the estimated grades of the individual rare earth oxides, were also estimated in the block model as a check to ensure the preservation of the total package and for validation, but these were not reported.
A strong correlation was observed between density measurements and TREO per cent values. A linear regression was therefore used to define a relationship between density and TREO per cent and subsequently used to estimate density values into the block model using the estimated TREO per cent grades in each block.
The block model was depleted for past production using current survey information pertaining to the underground development and mined-out areas. This ensured that parts of the model representing stopes and development workings were not included in the resource estimate.
Classification of the mineral resource took into consideration data quality (including location information), confidence in the structural framework and confidence in the resource estimate. This has been adjusted following the 2012 estimates based on the acquisition of new data as well as improved confidence in the geological framework following the recent structural geology interpretation.
Resource estimate for the tailings dams
In December, 2012, Snowden completed a mineral resource estimate of the tailings dams, which was reported with the December, 2012, mineral resource estimate. During mid-2013, the company moved and combined the tailings material (25,340 cubic metres) to an alternate location. The new tailings dam volume, including the surrounding berm, is 31,269 cubic m.
It was not possible to attribute the grades of the December, 2012, tailings-dam-grade models to any discrete portion of the new dam or berm due to commingling of material sourced from the original tailings dam mixed with contaminated soil. It must be considered that the tailings are now all mixed, and the average and diluted grade be applied to the whole.
The December, 2012, estimate of the tailings mineral resource comprised 24,560 cubic m (36,600 tonnes) at 8.8 per cent TREO plus Y2O3 of indicated resource and 780 cubic m (1,200 tonnes or around 4 per cent of the tailings) at 7.5 per cent TREO plus Y2O3 of inferred resource.
For reporting of the tailings mineral resource, the grade of the tailings was therefore combined and factored by 0.81 (0.81 equals 25,340/31,269, representing the ratio of volumes) so that the grade of the overall tailings is now reported as 7.18 per cent TREO plus Y2O3. This assumed the density remains unchanged, so the metal content is preserved. If the density is decreased, or GWMG is able to segregate tailings from waste, then the tonnage will decrease and the grade will increase, but the estimated metal content will remain unchanged. This grade is consistent with grab samples from the tailings.
The Indicated and inferred portions cannot now be separated, and therefore Snowden took the stance to include the entire tailings resource in the indicated category. Snowden elected to maintain the classification of the tailings resource as an indicated mineral resource because of the certainty that all of the tailings were relocated, the added dilution is added with a zero grade, the subsequent average grade is well above cut-off and the dump will be treated as a part of the environmental cleanup if the project succeeds in development into a producing mine.
Qualified person statement
The October, 2013, MRE has been prepared by Ivor Jones, BScHons, MSc, FAusIMM, CPGeo, the group general manager of geosciences with Snowden. He contributed to and supervised the mineral resource estimate for the Steenkampskraal rare earth project. Mr. Jones consents to the inclusion in this news release of the matters based on his information in the form and context in which it appears. Mr. Jones has sufficient experience, relevant to the type of deposit under consideration and to the activity which he is undertaking, to qualify as a qualified person as defined under National Instrument 43-101 -- Standards of Disclosure for Mineral Projects and supervised the preparation of the contents of the resource estimate section of this news release.
Brent Jellicoe, PGeo, is the chief geologist for Steenkampskraal Monazite Mine (Pty.) Ltd. and is the qualified person (as defined under NI 43-101) responsible for supervising all exploration activities and preparation of the technical content of this news release.
MINERAL RESOURCE STATEMENT FOR THE STEENKAMPSKRAAL MINERAL RESOURCE
(OCTOBER, 2013) AT A CUT-OFF OF 1 PER CENT TREO
TREO +
Area Class Tonnes Item Y2O3 TREO Y2O3 LREO
In situ mine Measured 85,000 Metal
tonnes 16,600 15,900 680 15,300
Grade (%) 19.54 18.74 0.8 18.01
Indicated 154,000 Metal
tonnes 22,800 21,900 930 21,000
Grade (%) 14.79 14.19 0.6 13.63
Inferred 20,000 Metal
tonnes 2,500 2,400 110 2,300
Grade (%) 12.77 12.22 0.55 11.72
In situ Indicated 320,000 Metal
exploration tonnes 44,100 42,300 1,820 40,600
Grade (%) 13.80 13.23 0.57 12.69
Inferred 40,000 Metal
tonnes 3,700 3,500 160 3,400
Grade (%) 9.30 8.91 0.39 8.54
In situ 85,000 Metal
measured tonnes 16,600 15,900 680 15,300
Grade (%) 19.54 18.74 0.80 18.01
In situ 474,000 Metal
indicated tonnes 67,000 64,200 2,750 61,600
total Grade (%) 14.16 13.54 0.58 13.00
In situ 60,000 Metal
inferred tonnes 6,200 5,900 270 5,700
total Grade (%) 10.46 10.01 0.44 9.60
Tailings Indicated 46,000 Metal
tonnes 3,300 3,200 150 3,100
Grade (%) 7.18 6.87 0.32 6.57
Area Class Tonnes Item HREO La2O3 CeO2 Pr6O11
In situ mine Measured 85,000 Metal
tonnes 620 3,440 7,550 850
Grade (%) 0.74 4.06 8.91 1.00
Indicated 154,000 Metal
tonnes 860 4,740 10,370 1,160
Grade (%) 0.56 3.07 6.72 0.75
Inferred 20,000 Metal
tonnes 100 520 1,160 130
Grade (%) 0.50 2.62 5.80 0.65
In situ Indicated 320,000 Metal
exploration tonnes 1,720 9,180 19,890 2,270
Grade (%) 0.53 2.87 6.22 0.71
Inferred 40,000 Metal
tonnes 140 760 1,680 190
Grade (%) 0.36 1.91 4.2 0.47
In situ 85,000 Metal
measured tonnes 620 3,440 7,550 850
Grade (%) 0.74 4.06 8.91 1.00
In situ 474,000 Metal
indicated tonnes 2,580 13,920 30,260 3,430
total Grade (%) 0.54 2.99 6.31 0.69
In situ 60,000 Metal
inferred tonnes 240 1,280 2,840 320
total Grade (%) 0.41 2.15 4.73 0.53
Tailings Indicated 46,000 Metal
tonnes 140 690 1,510 170
Grade (%) 0.29 1.49 3.25 0.36
Area Class Tonnes Item Nd2O3 Sm2O3 Eu2O3 Gd2O3
In situ mine Measured 85,000 Metal
tonnes 2,950 470 8 320
Grade (%) 3.48 0.55 0.01 0.38
Indicated 154,000 Metal
tonnes 4,100 650 15 450
Grade (%) 2.66 0.42 0.01 0.29
Inferred 20,000 Metal
tonnes 460 72 2 50
Grade (%) 2.29 0.36 0.01 0.25
In situ Indicated 320,000 Metal
exploration tonnes 7,960 1,280 32 860
Grade (%) 2.49 0.4 0.01 0.27
Inferred 40,000 Metal
tonnes 680 110 4 72
Grade (%) 1.7 0.27 0.01 0.18
In situ 85,000 Metal
measured tonnes 2,950 470 8 320
Grade (%) 3.48 0.55 0.01 0.38
In situ 474,000 Metal
indicated tonnes 12,060 1,930 47 1,310
total Grade (%) 2.52 0.41 0.01 0.28
In situ 60,000 Metal
inferred tonnes 1,140 180 6 120
total Grade (%) 1.90 0.30 0.01 0.20
Tailings Indicated 46,000 Metal
tonnes 590 94 2 67
Grade (%) 1.27 0.2 0.005 0.14
Area Class Tonnes Item Tb4O7 Dy2O3 Ho2O3 Er2O3
In situ mine Measured 85,000 Metal
tonnes 34 160 25 51
Grade (%) 0.04 0.19 0.03 0.06
Indicated 154,000 Metal
tonnes 46 220 31 62
Grade (%) 0.03 0.14 0.02 0.04
Inferred 20,000 Metal
tonnes 6 26 4 8
Grade (%) 0.03 0.13 0.02 0.04
In situ Indicated 320,000 Metal
exploration tonnes 100 450 64 130
Grade (%) 0.03 0.14 0.02 0.04
Inferred 40,000 Metal
tonnes 8 36 4 12
Grade (%) 0.02 0.09 0.01 0.03
In situ 85,000 Metal
measured tonnes 34 160 25 51
Grade (%) 0.04 0.19 0.03 0.06
In situ 474,000 Metal
indicated tonnes 150 670 100 190
total Grade (%) 0.03 0.14 0.02 0.04
In situ 60,000 Metal
inferred tonnes 14 62 8 20
total Grade (%) 0.02 0.10 0.01 0.03
Tailings Indicated 46,000 Metal
tonnes 8 37 5 11
Grade (%) 0.02 0.08 0.01 0.02
Area Class Tonnes Item Tm2O3 Yb2O3 Lu2O3
In situ mine Measured 85,000 Metal
tonnes 4 17 2
Grade (%) 0.005 0.02 0.002
Indicate d 154,000 Metal
tonnes 6 31 3
Grade (%) 0.004 0.02 0.002
Inferred 20,000 Metal
tonnes 1 2 0.3
Grade (%) 0.004 0.01 0.002
In situ Indicated 320,000 Metal
exploration tonnes 12 64 5
Grade (%) 0.004 0.02 0.002
Inferred 40,000 Metal
tonnes 1 4 0.5
Grade (%) 0.003 0.01 0.001
In situ 85,000 Metal
measured tonnes 4 17 2
Grade (%) 0.005 0.02 0.002
In situ 474,000 Metal
indicated tonnes 18 100 8
total Grade (%) 0.004 0.02 0.002
In situ 60,000 Metal
inferred tonnes 2 6 0.8
total Grade (%) 0.003 0.01 0.001
Tailings Indicated 46,000 Metal
tonnes 1 2 1
Grade (%) 0.002 0.004 0.001
Notes:
Material tonnes were rounded to three significant figures. The metal
tonnes for indicated and inferred totals were calculated by summing
the metal tonnes of each category in each area. Grades for in situ
mine and exploration area for each resource category are as reported
from data mine modelling. Grades were rounded to two decimal places
with the exception of Tm2O3 and Lu2O3 (which were rounded to three
decimals). Rare earth oxides may be divided into light rare earth
oxides and heavy rare earth oxides. LREO comprise lanthanum (La2O3),
cerium (CeO2), praseodymium (Pr6O11), neodymium (Nd2O3) and samarium
(Sm2O3). HREO consist of europium (Eu2O3), gadolinium (Gd2O3),
terbium (Tb4O7), dysprosium (Dy2O3), holmium (Ho2O3), thulium (Tm2O3),
ytterbium (Yb2O3) and lutetium (Lu2O3). Yttrium (Y2O3), thorium (ThO2)
and uranium (UO2) are also included in the oxides estimated.
For the purposes of this table, HREO does not include Y2O3.
We seek Safe Harbor.
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