For personal use only

ASX ANNOUNCEMENT

ASX: NWM

16 March 2022

Bulgera gold project resources exceed 200,000 ozs

on strength of 2021 drill programs

Highlights:

  • The Bulgera gold resource estimate increased 113% to 5.1Mt @ 1.2g/t gold for 200,130 ounces.
  • RC and diamond drilling conducted in 2021 intersected wide zones of gold mineralisation to extend the main lode beyond 500m down dip of the shallow Bulgera open pit.
  • Bulgera gold mineralisation has high recovery & low-cost processing characteristics as reported in recent ALS metallurgical study.
  • Norwest to commence deep reverse circulation (RC) drilling for additional gold bearing shear zones in the highly mineralised Bulgera Gold project area.

Norwest Minerals Limited ("Norwest" or "the Company") (ASX: NWM) is pleased to announce that the indicated and inferred gold resources at its Bulgera Gold project have increased to 5.1Mt @ 1.2g/t gold for 200,130 ounces (see JORC Resource table below). The new resource model includes all the 2021 reverse circulation1 and diamond drill data with many of the holes intersecting wide zones of strong gold mineralisation from 200m to over 500m downdip of the shallow Bulgera open cut. The Bulgera gold resources are complimented by high metallurgical recoveries (up to 98%) and low-cost processing parameters2. Norwest is planning to RC drill below several of the historical near-surface gold zones by targeting mineralisation at ~100 vertical metres where gold tenor across the Plutonic greenstone belt is commonly found to increase. The aim is to identify one or more additional gold hosted shear zone being similar to the main lode discovered below the Bulgera open cut.

Norwest's CEO, Mr. Charles Schaus commented: "Its more exciting news for Norwest, as we are delighted to announce the increase of our Bulgera gold resources to over 200,000 ounces. The new resource model includes all our 2021 RC and diamond drilling and certainly demonstrates that the gold tenor at Bulgera increases with depth. With this in mind, the Company is now planning to RC drill to 100 vertical metres below other historical gold zones that lie within the Bulgera project limits. The follow-up exploration drilling at Bulgera is expected to commence in Q2 CY2022 following this month's Heritage study program."

  1. ASX: NWM - Announcement 11 May 2021, 'High-grade lode identified at Bulgera project'
  2. ASX: NWM - Announcement 23 September 2021, 'Diamond drilling commences at Bulgera'

Norwest Minerals Limited - Bulgera Gold Resource Estimate Update

For personal use only

Figure 1 - March 2022 Bulgera project resource model showing 3D gold mineralisation grade shells with assigned indicated and inferred confidence categories.

Bulgera Resource Estimate Update

The previous mineral resource estimate for the Bulgera project was announced in April 20203 having a total 2.92Mt @ 1g/t for 93,880 ounces of gold. Since then, Norwest has completed reverse circulation (RC) and diamond drilling programs that have intersected additional gold mineralisation primarily within a high-grade gold lode extending over 500m down-dip of the Bulgera open cut.

Total RC drilling across the Bulgera Gold project now stands at 524 holes for 33,731 metres plus 7 Norwest diamond holes for 2,359 metres. RC and diamond drilling completed by Norwest since the previous resource estimate in April 2020 totals 69 holes for 11,138m and has focused primarily below the shallow Bulgera open cut with just 4 deep RC holes drilled below the Mercuri open cut.

Modelling of the entire Bulgera project drill dataset was undertaken by independent resource experts Hyland Geological and Mining Consultants ("HGMC") using MineSight software to construct the block model wireframes and run geostatistical and variography calculations. Kriging algorithms were applied to determine block gold grades and resource confidence levels. Details of the gold resource modelling and resource calculations are included in the JORC tables at the end of this announcement.

The March 2022 JORC 2012 compliant Mineral Resource for the Bulgera Gold project applying a 0.6g/t lower Au cut-off stands at:

Indicated Resources

Inferred Resources

Total Resources

Mt

Au (g/t)

Au Ozs

Mt

Au (g/t)

Au Ozs

Mt

Au (g/t)

Au Ozs

2.09

1.0

67,382

2.99

1.38

132,748

5.08

1.22

200,130

3 ASX: NWM - Announcement 8 April 2020, 'Bulgera resource upgrade and aircore drilling'

2

Norwest Minerals Limited - Bulgera Gold Resource Estimate Update

For personal use only

The gold resources reporting to the lower confidence 'Inferred' category reflect the wide spacing of the deep RC and diamond drill holes. Larger distances between drill holes limits the number of the gold assays captured by block search ellipsoids and, as a result, lowers the accuracy of the block's estimated gold grade. This is a primary factor in assigning the Indicated or Inferred confidence category to any given block within the model's mineralisation wireframes.

If drilling is located beyond a block's gold assay search-range then that block will be excluded from the resource tabulation and designated 'unclassified'. These 'unclassified' blocks are considered key areas requiring infill drilling. Likewise, where blocks are classified as Inferred, infill drilling is necessary to upgrade these areas to the Indicated category. Figure 1 shows the resource categories and the effect drill density has on determining the assignment of Indicated or Inferred confidence (or unclassified) to the blocks in the block model.

Metallurgical Test Work Results

Preliminary metallurgical testing was undertaken by ALS Global Metallurgical Services on three Bulgera gold RC samples4. The average gold grades for the three samples were 1.74g/t, 4.43g/t and 8.66g/t respectively.

All 3 gold samples returned excellent flow sheet and processing characteristics including:

  • High gravity separation and mercury amalgamation of the gravity concentrate to yield significant free liberated gravity recoverable gold (GRG) of 28.80%, 39.08% and 47.46% for composites 1 to 3 respectively.
  • High total extractable gold (via gravity plus standard leach) for composite 1 to 3 with overall gold recoveries of 95.6%, 92.6% and 98.3% respectively.
  • Fast gold leach kinetics for all gravity leach tests with the majority of the gold leaching in the first 2-4 hours.
  • Low sodium cyanide and lime consumption rates with Perth tap water for all leach tests.
  • Low levels of organic carbon decreasing the likelihood of preg-robbing of gold in solution during cyanidation.
  • Low concentrations of base metals decreasing the possibility of excess cyanide consumption through preferential complexing with these metals.
  • Low levels of arsenic, decreasing the likelihood of refractory gold deportment.
  • Low levels of antimony, thus avoiding high pH which may form passivating oxide layers on the gold surfaces, which can have a detrimental effect on gold cyanidation.

4 ASX: NWM - Announcement 23 September 2021, 'Diamond drilling commences at Bulgera'

3

Norwest Minerals Limited - Bulgera Gold Resource Estimate Update

For personal use only

Bulgera Diamond Drilling

The 7-hole Phase 1 drilling programme required 953 metres of RC pre-collars and 1,406 metres of HQ diamond core tails. The main broad mineralised zone was intersected by all 7 diamond holes BDD21001 to BDD21007 extending the interpreted shear zone identified in the RC holes drilled up dip5 to over 500m from the shallow Bulgera open cut.

Diamond drill holes BDD21003 to BDD21007 intersected the shear zone at predicted depths and all displayed widths and geological features consistent with the geological logging of the RC holes intersecting the high-grade gold zone. The target shear zone intersected by the diamond drilling and hosting the RC gold mineralisation is identified as a 'sheared silica-sericite-biotite altered amphibolite (+/- sulphides) with patchy destructive silica flooding and intervals of late quartz veining'. The significant intercepts for the recent RC and 7-hole diamond drilling programs are shown on the long section in figure 2 and listed in Table 1 below. The relevant JORC Tables describing the diamond drilling are located in ASX Announcement lodged 03 February 20226.

Figure 2 - Long section with new diamond drill intercepts and significant RC intersections. Note: the projected gold lode (pink) dips away from viewer at ~45° thus the distance down the dip of the lode is approximately twice the vertical distance shown. For example, the gold intercept point for BDD21005 measures ~250m from the long section surface but is ~500m down dip of surface as shown in figure 3.

  1. ASX: NWM - Announcement 11 May 2021, 'High-grade lode identified at Bulgera Project'
  2. ASX: NWM - Announcement 03 February 2022, 'Norwest extends new high-grade gold lode at Bulgera'

4

Norwest Minerals Limited - Bulgera Gold Resource Estimate Update

For personal use only

Figure 3 - Simplified geological cross-section showing several RC and diamond hole gold intersections. Hole BDD21005 demonstrates that the gold mineralisation continues beyond ~500m down dip from surface.

RC exploration drilling to test below 100m at historical gold prospects

Norwest's deep drilling success below the Bulgera open cut has encouraged the Company to plan similar exploration drilling below a number of the historical gold deposits and prospects located within the Bulgera tenements.

Figure 4 - Map showing the lack of deep drilling (+100 vertical metres) across the many Bulgera gold deposits and prospects.

5

This is an excerpt of the original content. To continue reading it, access the original document here.

Attachments

  • Original Link
  • Original Document
  • Permalink

Disclaimer

Norwest Minerals Ltd. published this content on 15 March 2022 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 15 March 2022 22:07:03 UTC.