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 is accessible via the public Tanami Road that runs between the Stuart Highway in the Northern Territory and the Great Northern Highway in Western Australia. Accessibility within the CTP area is possible on well formed, partly sealed, private mine haulage roads, pastoral station tracks and exploration tracks.

Geology and Mineralisation

The Central Tanami Project Joint Venture (“CTPJV”) 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 identified 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 future exploration and development activities on the CTP.    

 

Joint Venture Activities

Drilling

The CTPJV resumed field activities on the CTP in May 2022, during the periods between May and October 2022 (the “2022 Field Season”) and May and October 2023 (the “2023 Field Season”), with the undertaking of both diamond core drilling (“DD”) and reverse circulation drilling (“RC”). Since the resumption of field activities 155 drill holes have been completed for a total of 33,496.8 metres.  This drilling has been directed at the Groundrush Gold Deposit (Groundrush”), Ripcord Gold Deposit (“Ripcord”), Western Dolerite Gold Prospect (“Western Dolerite”), Jims Gold Deposit (“Jims”), Beaver Gold Deposit (“Beaver”), Tandem Prospect (“Tandem”) and the Groundrush-Ripcord Link (“Groundrush-Ripcord Link”) and the Groundrush North (“Groundrush North”) targets. .

  • Groundrush

A campaign of drilling commenced at Groundrush during the 2022 Field Season on a program designed to further assess the down dip and down plunge extensions of known mineralised structures down to a vertical depth of approximately 600 metres with a view to expanding the projects mineral resources. It was completed during the 2023 Field Season.By the cessation of drilling 7 holes had been completed and a further 12 RC pre-collars drilled for a combined total meterage of 6,011.5 metres. Final results remain pending for the 7 completed holes.  12 diamond core tails remain to be drilled.

The RC pre-collar/ DD tail campaign comprised a total of 15 of the original 20 holes planned. Four diamond core tails (GRRCD0001, GRRCD0002, GRRCD0007 and GRRCD0018) were excluded from the program due to excessive movement of RC pre-collars. A fifth hole (GRRCD0020) could not be drilled due to its proximity to the historic Groundrush open pit bund wall. Core logging and sampling proceeded as planned. Results are pending for all holes.

 

Groundrush drill hole plan

 

Groundrush is located on Mining Lease ML22934 approximately 45km northeast of the Central Tanami Mill site. Groundrush was subject to mining activities between 2001 and 2005, yielding 611,000 ounces of gold at a reconciled grade of 4.5 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.

  • Ripcord

A 41 hole RC campaign commenced at Ripcord during the 2022 Field Season and was completed during the 2023 Field Season.  The campaign was designed to infill historic drilling along the northerly strike extensions of the Ripcord deposit with view to expanding the projects mineral resources.

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

  •  10.0 metres @ 0.99 g/t gold from 34.0 metres in RCRC0002
  •  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
  •  4.0 metres @ 2.79 g/t gold from 55.0 metres in RCRC0003
  •  4.0 metres @ 3.79 g/t gold from 120.0 metres in RCRC0006
  •  5.0 metres @ 3.50 g/t gold from 110.0 metres in RCRC0016
  •  4.0 metres @ 3.27 g/t gold from 97.0 metres in RCRC0021
  •  9.0 metres @ 1.65 g/t gold from 70.0 metres in RCRC0022
  •  10.0 metres @ 1.61 g/t gold from 56.0 metres in RCRC0030
  •  17.0 metres @ 1.50 g/t gold from 38.0 metres in RCRC0035

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

 

Ripcord long section. View looking west.

 

Drilling was completed on a second phase of RC drilling at Ripcord during the 2023 Field Season, with 52 holes drilled for an advance of 6,455 metres. Drilling was aimed to enhance resource classification by improving drill density in the northern area and closing off open sections in the southern part of the deposit. Assay results are pending for all holes.

Ripcord is located on Mining 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.

 

  • Western 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

 

  • Jims

A campaign of diamond core drilling was completed at Jims, with 7 DD drilled for 2,677.1 metres. The campaign 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.Final results remain pending.

Results for all holes have now been received yielding 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.

 

Jims drilling, view looking west

 

Jims drilling, view looking North

 

A further 3 holes were drilled at Jims during the 2023 Field Season. The RC pre-collar and DD tail holes were targeted at interpreted down plunge extensions and an underexplored corridor north of the previous DD campaign. Results are pending for all holes.

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.

The Jims gold deposits are 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.

 

  • Tandem
     

A 12-hole RC drilling campaign was completed at Tandem totalling 2,160 metres. Situated northeast of Groundrush, Tandem represents an early-stage target identified by the discovery of elevated gold results from historic reconnaissance drilling, which are located near a north-south trending magnetic feature.

Results have been received for all holes, returning several significant intercepts based on a 0.5 g/t gold cut-off level including 3.0 metres @ 2.34 g/t gold and 2.0 metres @ 1.80 g/t gold.

 

Tandem drill hole plan.

 

  • Groundrush-Ripcord Link

Drilling was completed during the 2023 Field Season on the Groundrush-Ripcord Link campaign. It represents a Northern Territory Government co-contribute campaign, part of the Round 16 Resourcing the Territory Exploration Grants for the Central Tanami Project.

The 3 hole RC pre-collar and DD tail campaign totalled 2,317 metres and was situated between Groundrush and Ripcord targeting the possible down plunge extension of Groundrush, approximately 500 metres horizontally from the current Groundrush resource model. Results are pending for all holes.

 

  • Groundrush North

Drilling was completed during the 2023 Field Season on the 6 hole, 1,440 metre RC campaign that targeted the underexplored northerly strike extension of the Groundrush shear zone, focusing on interpreted dilational zones. Results are pending for all holes.

 

  • Beaver

Drilling was completed during the 2023Field 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 totalled 1,210 metres targeting depth extensions of known mineralisation below the historic open-pit.  Results are pending for all holes.

 

Mineral Resources

Work on updating the CTPJV Mineral Resource estimates has continued, with updates completed for 11 deposits. 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.