Central Tanami Exploration

 

Central Tanami Project Joint Venture (Tanami Gold 50%)

The Central Tanami Project (“CTP”) is located 650 kilometres northwest of Alice Springs in the Tanami Region of the Northern Territory. It comprises four granted Exploration Licences, two Exploration Licences Applications and five granted Mineral Leases that cover a total area of 2,110km², encompassing highly prospective, yet underexplored geological sequences renowned for their endowment of gold.

Central Tanami Project Tenement Holding

 

The project is accessible from the  Tanami Road, which runs between the Stuart Highway in the Northern Territory and the Great Northern Highway in Western Australia. Access within the CTP area is through well formed, partly sealed, private mine haulage roads, pastoral station tracks and exploration tracks.

Geology

The CTP tenement holding encompasses a zone of Proterozoic volcanic and sedimentary rocks that display lower greenschist to amphibolite facies metamorphism. It overlies an Archean basement and was intruded by granites.

The gold deposits within the CTP are predominantly hosted within the Neoproterozoic Mt Charles Formation, an interbedded sequence of fine to coarse grained sedimentary rocks and basalt up to 1.5 km thick. This Formation is interpreted to be the lateral equivalent of the Dead Bullock Formation, which hosts the world class Callie gold deposit to the southeast and the Stubbins Formation that hosts the Bald Hill deposits to the northwest.  The Mt Charles Formation however, forms a broad syncline sandwiched between and wrapping around the Coomarie and Frankenia granite intrusions with a dominant moderate to steep west-northwest dip within the CTP area.

The key CTP deposit, the Groundrush Gold Deposit (“Groundrush”) sits in an almost arcuate belt of sediments between two major granitoid intrusions.  It represents a reverse fault orogenic system, with mineralisation typically hosted in stacked vein sets with a variety of orientations, as well as sub-vertical quartz-filled shear zones, within a fractionated dolerite sill. Minor mineralisation also extends into the adjacent turbiditic sediments. Along with the various orientations of veining, there also exists a variety of types, which has been identified over a collective strike length of 1,900 metres, with mineralisation predominantly occurring as free gold with variable amounts of pyrite and arsenopyrite.

 

 History

Gold was first discovered in the Tanami Desert in 1898 and small-scale mining dates back to the early 1900’s. Operations in the region were sporadic until the 1980’s when the underground Tanami Gold Mine was developed by Normandy Mining (now Newmont), with first gold production in 1983.

Various companies and joint ventures have explored and operated in the region subsequent to this time.  In 1987 the Tanami JV operations operated by Zapopan NL commenced but were discontinued in 1994.   Otter Resources and Shell Australia then acquired the Tanami Plant and established a multi-pit operation in 1995 that ceased production in 2001.

Normandy Mining seeking additional ore to sustain its Tanami Operation discovered Groundrush in 1999, with mining carried out from 2001 to 2005, with ore processed at the Central Tanami Processing Plant.  Mineralisation was discovered at the Ripcord Gold Deposit (“Ripcord”) in 2001.

Tanami Gold NL (“Tanami Gold” or the “Company”) acquired the CTP in 2010 conducting resource drilling over the subsequent years to support studies into the potential recommissioning of mining operations.

In 2015, Tanami Gold entered a Joint Venture agreement with Northern Star Resources Limited (“Northern Star”), with Northern Star acquiring an initial 25% interest in the CTP, with options to increase their interest up to 60%. In September 2018, Northern Star had settled the first option resulting in it acquiring an additional 15% increasing Northern Star’s equity to 40%.

On the 15 September 2021, Tanami Gold completed a transaction with Northern Star to establish a 50/50 joint venture covering the CTP with the transfer of a 10% interest from Tanami Gold to Northern Star.  A Joint Venture management company was registered, through which both Tanami Gold and Northern Star jointly fund all exploration and development activities on the CTP.     

 

Joint Venture Activities

Drilling

Activities resumed on the CTP in May 2022, effectively operating each field season, between May and October.  Since the resumption of field activities a total of 308 diamond core (“DD”), reverse circulation (“RC”) and air core (“AC”) drill holes have been completed for an advance of 45,961.9  metres to the end of June 2024.  This drilling has been directed at the:

-         Groundrush Gold Deposit (Groundrush”), Ripcord Gold Deposit (“Ripcord”), Western Dolerite Gold Prospect (“Western Dolerite”) and the Groundrush-Ripcord Link, Tandem, and Groundrush North targets in the Groundrush Area;

-         Miracle West Target (“Miracle West”), Funnelweb Gold Deposit (“Funnelweb”) in the Tanami Mine Corridor area;

-         Jims Gold Deposit (Jims) in the Tanami Southwest area; and

-         Beaver Gold Deposit (“Beaver”) and the North Limb target in the Molech area.

 

·         Groundrush Area

Groundrush Gold Deposit

Groundrush is located on Mineral Lease ML22934 approximately 45km northeast of the Central Tanami Mill site. It was subject to mining activities between 2001 and 2005, yielding 611,000 ounces of gold at a reconciled grade of 4.0 g/t gold through open-pit mining.

The Groundrush deposit represents a reverse fault orogenic system. Mineralisation is typically hosted within stacked vein sets of various orientations and sub-vertical quartz-filled shear zones, found within a fractionated dolerite sill. Minor mineralisation extends into turbiditic sediments. Alongside the diverse orientations of veining, various types like shear, extensional and a shear-extension hybrid style of veining exist.

Mineralisation has been delineated over a cumulative strike length of 1900 metres. Individual lodes extend from 50 to 970 metres in length and vertically from 50 to 250 metres. These steeply dipping lodes have a true thickness ranging from 1-2 and up to 35 metres and plunge to the south at around 10° while remaining open.

A campaign of drilling commenced at Groundrush in the 2022 field season and was completed during the 2023 field season.  

The RC/DD  campaign consisted of 15 holes of the original 20 planned holes. Four DD tails (GRRCD0001, GRRCD0002, GRRCD0007 and GRRCD0018) were excluded from the program due to excessive deviation  of RC pre-collars. A fifth hole (GRRCD0020) could not be drilled due to its proximity to the historic Groundrush open pit bund wall.  The campaign was designed to assess the down dip and down plunge extensions of known mineralised structures to a vertical depth of approximately 600 metres, with the objective of expanding the projects mineral resources.

 The campaign successfully returned several significant intercepts based on a 1.00 g/t gold reporting level, including:

  • 2.80 metres @ 7.86 g/t gold from 456.30 metres in GRRCD0003
  • 7.00 metres @ 2.42 g/t gold from 158.00 metres in GRRCD0006
  • 2.77 metres @ 3.51 g/t gold from 593.23 metres in GRRCD0006
  • 8.00 metres @ 5.28 g/t gold from 437.00 metres in GRRCD0008
  • 4.35 metres @ 2.27 g/t gold from 395.83 metres in GRRCD0009
  • 15.72 metres @ 2.31 g/t gold from 414.00 metres in GRRCD0009
  • 13.45 metres @ 6.40 g/t gold from 464.55 metres in GRRCD0010
  • 2.00 metres @ 5.20 g/t gold from 510.20 metres in GRRCD0010
  • 1.47 metres @ 7.22 g/t gold from 437.14 metres in GRRCD0011A
  • 3.60 metres @ 22.51 g/t gold from 263.00 metres in GRRCD0013
  • 4.16 metres @ 2.43 g/t gold from 253.84 metres in GRRCD0015
  • 4.00 metres @ 5.82 g/t gold from 390.00 metres in GRRCD0017

The results received are encouraging and align well with expectations validating results from historical drilling. In particular, the results from the southern end of the deposit are seen as very positive as the CTPJV plan for future activities targeting the deeper mineralisation at Groundrush.

Groundrush Long Section, view looking east.

 

 

Ripcord Gold Deposit

Ripcord is located on Mineral Lease ML22934 approximately 3km southeast of Groundrush. The geology and deposit style at Ripcord shows similarities to the nearby Groundrush deposit, although it has not been definitively established whether the host dolerite body is the same as the one hosting gold mineralisation at Groundrush. The host dolerite unit at Ripcord exhibits analogous fractionation textures to those as observed at Groundrush, with fractionated quartz dolerite flanked on both sides by transitional quartz dolerite zones.

Primary gold mineralisation principally occurs within the larger main dolerite body, with minor mineralisation extending into the turbiditic sediments along the footwall contact. The main mineralised lodes consist of, 1 to 6 metre wide zones of quartz veining oriented in a north to northwest direction and dipping at 80° to the southwest.

The mineralised zone’s strike length is around 1,200 metres, with a known down dip extent from drilling data of approximately 150 metres. The width of the primary mineralisation zone is estimated at about 40 metres.

A 41 hole RC campaign commenced at Ripcord during the 2022 field season and was completed during the 2023 field season (Phase 1).  It was  followed by a 54 hole RC campaign (Phase 2).  These campaigns were designed to infill historic drilling along the northerly strike extensions of the Ripcord deposit with the objective of expanding the projects mineral resource.

Results have been received for all holes, yielding a series of significant intercepts based on a 0.5 g/t gold cut-off level including:

 

  • 14.0 metres @ 7.47 g/t gold from 96.0 metres in RCRC0002
  • 14.0 metres @ 1.81 g/t gold from 117.0 metres in RCRC0002
  • 17.0 metres @ 1.50 g/t gold from 38.0 metres in RCRC0035
  • 1.0 metre @ 21.00 g/t gold from 122.0 metres in RCRC0050
  • 8.0 metres @ 2.61 g/t gold from 71.0 metres in RCRC0054
  • 4.0 metres @ 5.83 g/t gold from 57.0 metres in RCRC0063
  • 7.0 metres @ 3.02 g/t gold from 121.0 metres in RCRC0068
  • 4.0 metres @ 5.56 g/t gold from 63.0 metres in RCRC0101
  • 2.0 metres @ 10.08 g/t gold from 24.0 metres in RCRC0126
  • 23.0 metres @ 2.09 g/t gold from 69.0 metres in RCRC0126
  • 12.0 metres @ 1.91 g/t gold from 107.0 metres in RCRC0127

The intercepts primarily occur within quartz-sulphide (pyrite) bearing veinlets in dolerite and have confirmed the presence of mineralisation over 450 metres along strike of the northerly extension of the Ripcord deposit.

Ripcord drill hole plan

 

Western Dolerite Gold Prospect

Western Dolerite is located on Mineral Lease ML22934 approximately 45km northeast of the Central Tanami Mill site, to the immediate west of the Groundrush gold deposit. The Western Dolerite is a relatively well defined unit, that appears comparable in size and similar in mineralogy to the nearby Groundrush Dolerite.

Results were received for the 14 hole RC campaign that was completed in the Western Dolerite area during the 2022 field season. Encouraging intercepts received include 6.00 metres @ 3.31 g/t gold, 8.00 metres @ 2.13 g/t gold and 6.00 metres @ 2.60 g/t gold.

The 14 hole campaign was designed to infill an area of known mineralisation within the Western Dolerite, a small dolerite unit located several hundred metres to the west and orientated broadly parallel to the Groundrush deposit.  The drilling confirmed the steeply southwest dipping geometry of the Western Dolerite unit and intersected multiple intervals of quartz-sulphide veining.

Western Dolerite Drill Hole Plan

 

  • Tanami Mine Corridor Area

Miracle West Target

The Miracle West target represents the westerly extension of the previously mined Miracle Gold Deposit.  It straddles the boundary between Mineral Lease ML33760 and Exploration Licence EL26926 approximately 3km southwest of the Central Tanami Mill Site.

Mineralisation occurs predominantly as gold in sulphides (pyrite, arsenopyrite, and pyrrhotite), and is hosted within quartz veins within weakly deformed basalt and medium- to coarse-grained clastic sediments of the Mount Charles Formation.

A 14 hole, 1,340 metre AC campaign has been completed at Miracle West focusing on the southwestern extension of the main mineralised structure.  The campaign specifically targeted the intersections of interpreted structural corridors and lithological transition zones between sedimentary units and basalts of the Mt Charles Formation.

Drilling of the inclined holes continued until blade refusal, with sampling from the drill rig conducted on a metre basis.  Initial analysis was performed on four metre composite samples, while individual metre samples were collected for follow-up analysis from any composite interval that yielded a result greater than 0.10 g/t gold.

Several significant intercepts were returned from the individual metre samples including:

  • 27.0 metres @ 1.55 g/t gold from 60.0 metres in drill hole MWAC0004
  • 4.0 metres @ 2.97 g/t gold from 88.0 metres in drill hole MWAC0004
  • 4.0 metres @ 1.33 g/t gold from 89.0 metres in drill hole MWAC0008
  • 10.0 metres @ 2.11 g/t gold from 73.0 metres in drill hole MWAC0009

 

Miracle West Air Core Drillhole Layout

 

 

A 12 hole, 1,976 metre campaign of RC drilling was completed during the June-24 quarter.  The RC holes were planned to test between the intercepts from the 2023 AC campaign and to evaluate the potential for down-dip mineralisation below the current drilling extents. Drill holes were spaced at 50m along four 50 metre spaced drill lines.  Results are pending for all holes.

 

  • Tanami Southwest Area

Jims Gold Deposit

Jims is located on Mineral Lease (Southern) MLS168, approximately 23 kilometres southwest of the Central Tanami Mill site. Mining at Jims was previously carried out during the mid-1990’s, with open pits established over the Main and Central deposits.  Gold mineralisation is located mostly on the north-eastern side of an interpreted north-northwest trending regional fault, with mineralisation hosted by pillow and undifferentiated basalt, intercalated with minor sediments.

Two campaigns of drilling have been completed at Jims. The initial campaign was a 7 hole DD campaign that was designed to follow-up drill results received from a 2018 DD campaign directed at the Jims Main deposit and to provide additional structural and lithological information.

Results for the initial campaign yielded a series of significant intercepts based on a 1.00 g/t gold cut-off level including:

  • 2.02 metres @ 4.85 g/t gold from 396.98 metres in NJDD0002;
  • 11.90 metres @ 1.87 g/t gold from 287.00 metres in NJDD0004;
  • 20.00 metres @ 1.90 g/t gold from 326.00 metres in NJDD0004;
  • 4.35 metres @ 4.56 g/t gold from 356.00 metres in NJDD0004; and
  • 3.00 metres @ 12.72 g/t gold from 338.00 metres in NJDD0007.

The second campaign was 3 hole, 997.10 metres RC/DD  campaign that targeted the interpreted down plunge extensions and an underexplored corridor north of the initial DD campaign.

Assays received generated several encouraging intercepts based on a 1.00 g/t gold cut-off level including:

  • 14.00 metres @ 2.74 g/t gold from 251.00 metres in drill hole JPRCD0001
  • 2.00 metres @ 16.39 g/t gold from 83.00 metres in drill hole JPRCD0003
  • 3.81 metres @ 4.39 g/t gold from 208.42 metres in drill hole JPRCD0003

The intercepts align well with expectations for the structurally controlled mineralisation, with the obtained intercepts displaying lots of veining and pervasive sericite alteration within the variably textured basalt host rock.

 

Jims Long Section, view looking east

 

 

  • Molech Area

Beaver Gold Deposit

Beaver is located within granted Mineral Lease (Southern) MLS180, which is located approximately 36 kilometres west of the Central Tanami Mill Site in the Molech area.  Beaver was previously subject to open-pit mining by Otter between June 1999 and April 2001, with 540 kt mined at a reconciled grade of 3.3 g/t gold for 57 kozs of gold. Historic production came from two dominant structures locally named the Main and East Lodes. Both lodes are offset by cross cutting faults with a displacement of 15 to 20 metres. Gold mineralisation is hosted by intercalated mudstone, siltstone, sandstone, coarse grained volcanoclastic units, and undifferentiated basalt from the Mt Charles Formation.

Drilling was completed during the 2023 field season on the Beaver campaign, in the Molech area. This campaign represents a Northern Territory Government co-contribute campaign, part of the Round 16 Resourcing the Territory Exploration Grants for the Central Tanami Project.

The 2 hole DD campaign targeted the  depth extensions of known mineralisation below the historic Beaver open-pit, yielding abest intercept of 3.18 metres @ 4.78 g/t gold and confirming the extension of known mineralisation. There are additional significant intercepts in the second hole, but further modelling is required to determine how these results fit with the known mineralisation.

 

Beaver Long Section. View looking north.

 

 

Mineral Resources

Work on updating the CTPJV Mineral Resource estimates is continuing. The updates are part of an ongoing transition of the Central Tanami Project Mineral Resource estimates to allow these estimates to be reported in accordance with the 2012 Edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (the “2012 JORC Code”). Mineral Resource estimates for a further 13 Central Tanami Project gold deposits are in progress.

The updates were compiled by mining consultants MoJoe Mining Pty Ltd (“MJM”) using revised geological models that better reflect the mineralised systems. The reported Mineral Resources have been tightly constrained by Whittle and Stope Optimisations with deposit specific cut-off grades based on a A$2,700 per ounce gold price, haulage to the existing Central Tanami mill site, benchmark operating costs and free milling processing recoveries.

The Mineral Resources for the Central Tanami Project (Tanami Gold 50% - Northern Star 50%) as of 30 June 2023, total 25Mt grading 3.2 g/t gold for 2.6Mozs.