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Auger Drilling to Commence at Yarbu Gold Project

Auger Drilling to Commence at Yarbu Gold Project


  • Auger drilling program comprising ~660 holes set to commence to test strong gold in soil geochemical anomalies identified at Yarbu1 earlier this year
  • Anomalies correspond to potential gold mineralisation identified during historical drilling, suggesting Yarbu could contain multiple structural gold targets
  • Minimal exploration undertaken over much of TSC’s 220sq km Yarbu tenement package
  • Newly reprocessed historical geophysical data has highlighted previously unknown folding within TSCs ground¹ which will be tested with the auger drilling
  • TSC has appointed a Kalgoorlie-based drilling contractor to undertake the maiden auger drilling campaign at Yarbu
  • Yarbu is located in a highly prospective location along the Marda-Diemals greenstone belt, adjacent to Ramelius Resources (ASX:RMS) Marda Gold Project
  • Further work programs designed to test other priority targets within TSC’s portfolio are currently being finalised and details will be announced shortly


Commenting on the commencement of auger drilling, CEO Simon Phillips said:

“We are looking forward to getting our maiden exploration campaign underway at Yarbu, an area which we believe has the potential to host multiple structural gold targets.  Auger drilling provides us with a low-cost, yet highly effective, means to test several encouraging areas within Yarbu that have been detected during the recent reprocessing of geophysical data.  Data from this Auger program will be used to generate and prioritise follow-up drill targets.

Yarbu forms a key part of our 22km strike along the highly prospective Clampton Fault which is known to host significant gold mineralisation and remains largely underexplored by modern techniques. Our team has worked hard to secure a strong foothold within this highly prospective region within the WA goldfields and we look forward to advancing our systematic exploration programs over the coming months.”


Twenty Seven Co. Limited (ASX: TSC) (“TSC” or “the Company”) is pleased to announce that the Company is set to commence an auger drilling program at the Company’s 100%-owned Yarbu Gold Project (“Yarbu”) located approximately 160km NE of Southern Cross and approximately 90km NW of the Company’s 100%-owned Mt Dimer Project in Western Australia.

The Company has appointed Kalgoorlie-based drilling contractor, Gyro Australia, to undertake this auger drilling campaign which will comprise approximately 660 holes to test bedrock geochemical signatures using a low impact Landcruiser-mounted auger drilling rig (Figure 1).

Drilling will comprise shallow 2-3m deep, depending on penetration depths, auger soil sample drill holes across the entire tenement package.


Figure 1: Gyro Australia’s Landcruiser mounted auger drilling rig will be used to maintain low impact disturbance and collect geochemical samples. Picture from Gyro Australia’s library.


Auger Drilling Program Summary

As previously reported (see ASX announcement dated 16 April 2021), TSC’s geological staff have been collating and reviewing historical soil geochemistry which shows that Yarbu has a complex geological structural history, and this coupled with the reprocessing of open file historical geophysical surveys, has confirmed the presence of favourable structural settings within the tenement package.

Historical geochemical samples mainly comprise auger sampling which were tested only for limited geochemical elements, and at much higher detection limits compared to what is now available at commercial labs.  TSC will use a low detection limit assaying technique which produces results on a full suite of elements, which will provide new insights into potentially masked mineralisation at depth. Significant regional historical gold (Au) in soil geochemistry as well as associated Arsenic (As), and Lead (Pb) corresponding to gold mineralisation has been identified in historical drilling.

Drilling is designed on a two-pronged approach; firstly, to identify elemental alteration halos within the tenement, which can be seen from the historical geochemical sampling undertaken around Yarbu, and secondly to test newly discerned fold structures that were identified from TSC’s reprocessing of the regional geophysics.

Drilling has been designed on an 800m x 400m grid pattern which will give maximum coverage of the tenements and will also give minimum spacing to identify geochemical alteration halos.


Next Steps

Planned activities at Yarbu include the following:

  • Commencement of Auger drilling campaign this month;
  • Compilation of all the historical soil data into a single database, which will provide the TSC geological team an unparalleled insight into the geochemical signature of known mineralisation around the Yarbu tenements and coupled with the new geochemical data, will unlock further details; and
  • Modelling of drilling data and planning for further activities which may include further infill drilling.


Figure 2: Regional geology map with historical auger points colored by Au_ppb


Figure 3:Regional geology map with historical auger points colored by As_ppm


Figure 4: Regional geology map with historical auger points colored by Pb_ppm


Figure 5: Map showing RTP_tile_Eshade magnetics under historical geochemical samples coloured by gold_ppb.  Folding is clearly visible over the central tenement which are potential trap sites for gold mineralisation.  The cluster of Geochemical samples, which shows elevated gold to the west of the tenements, are small but high grade gold occurrences.



  • ¹ Refer to ASX announcement dated 16th April 2021: Review of historical soil data identifies gold in soil anomalies around Yarbu Gold Project


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