Hi,
I went through yesterday's Pernatty Drill Update announcement, with a retired Aussie based geologist, who has had 40 years of experience in SA. Here is a summary of our discussion.
Firstly, you will see that in today's TAS AGM Presentation, there was a reference to Punt Hill, which is currently being explored by Red Metal (RDM). Given that Punt Hill is very near to Carrapateena, and only 15 kms away from TAS's Pernatty tenement, the information contained in RDM's very recent AGM Presentation is quite interesting:
http://www.redmetal.com.au/images/stories/pdf/Red_Metal_AGM_Nov_2020_ASX.pdfMoving along, in yesterday's Pernatty Drill Update announcement, you will see mention of quartzite (most probably Arcoona Quartzite).
Carrapateena lies at the intersection of a major NNE trending structure and a NW trending fault corridor, which is thought to have
played a role in focussing the Olympic Dam mineralisation. The cover sequence at Carrapateena comprises outcroppings of Arcoona Quartzite. The following article titled "Geophysical Characteristics of the Carrapateena Iron-Oxide Copper-Gold Deposit", which was published online on February 26th, 2019, contains two references to Arcoona Quartzite:
https://www.tandfonline.com/doi/pdf/10.1071/ASEG2012ab160In the following Powerpoint Presentation titled "Carrapateena: Discovery and Early Exploration". which was presented by Lisa Vella at the 23rd ASEG Conference and Exhibition Exploration Undercover Workshop on August 15th, 2013, you will find three references to Arcoona Quartzite:
https://www.aseg.org.au/sites/default/files/2013_Uncover_Vella_L.pdfIn the above presentation, you will see on page 12 a diagramm titled " Schematic Geological Section (with resistivities annotated)". On the left you will see the first reference to Arcoona Quartzite. As Lisa Vella stated: "Carrapateena lies under 470m of moderately conductive Stuart Shelf sediments, presenting significant technical challenges to exploration". Part of this coverage is the Arcoona Quartzite (in yellow). It is our belief that at Pernatty TAS have also encountered this Arcoona Quartzite coverage and thus are having the same difficulties that OZ Minerals encountered when they began drilling at Carrapateena. This means that the Copper ore body lies much deeper i.e. between ca. 470 and 1470 meters. Having said this, although Pernatty seems to be very similar in geology to Carrapateena, there is still no guarantee that at depth TAS will find the same sort of very good Copper grades and major zone intervals that OZ Minerals did.
Moving along even further, in BHP's massive 320 page "Olympic Dam Expansion - Appendix K - Groundwater and Geochemistry" report from 2009, you will find 63 references to Arcoona Quartzite (or Simmens Quartzite as it is also known). You will also find a reference to the Pernatty Upwarp, as well as 5 references to the Pernatty Lagoon:
https://www.bhp.com/-/media/bhp/regulatory-information-media/copper/olympic-dam/0000/draft-eis-appendices/odxeisappendixkgroundwaterandgeochemistry.pdfFinally, as part of a University of Adelaide and Deep Exploration Technologies collaboration, a report was compiled by Oliver Hughes, titled "The Mesozoic sediments around Andamooka, South Australia; stratigraphy, geochemistry and IOCG exploration potential". In this report Arcoona Quartzite is mentioned 22 times. This includes the mention of Arcoona Quartzite in a number of diagrams i.e. Figure 3 on page 44 and Figure 16 on page 58, as well as photographs of Arcoona Quartzite, i.e. Appendix 24 on page 104, Appendix 25 on page 105 and Appendix 33 on page 114.
https://digital.library.adelaide.edu.au/dspace/bitstream/2440/96174/1/02wholeGeoHon.pdfIn light of all of the above, it is no surprise to us, that TAS has encountered "extremely abrasive quartzite" at Pernatty, which is almost surely Arcoona Quartzite (or Simmens Quartzite as it is also known). Our feeling is that Pernatty shares the same sort of geology as Carrapateena, rather than that found at Mt. Gunson. We form this conclusion on the basis that at Mt. Gunson, most of the Copper mineralisation has been found at very shallow levels i.e. if Pernatty was a Mt. Gunson type of Copper deposit, TAS would probably have already found visible Copper near the surface i.e. during their RC drilling, much of which that has already been completed.
As they say, the plot (or deposit?) thickens.
Cheers.
(20min delay)