Mark Twain wrote, "There are three kinds of lies: lies, damned lies, and statistics."... by which he meant that statistics beguiled him. The same might be said of geophysics... such enchanting and seductive deception.
I was unsurprised to see multiple results carrots teased for February release start to drop straight after the cashflow report, but pleasantly surprised to see a rip-snorting 'Antler look-alike' coincident mag-IP target drop the next trading day. A nice change up from Roadrunner's 'meh' targets, or Discuss's more interesting but probably fading hopes (a Baghdad style 0.2g/t Au and 0.2% Cu open-pit porphyry but starting at 400m depth?). I hoped, but after finally looking closer, what was in the box wasn't what was on the label...
I'm a suspicious guy as you know, for good reason, feel like Diogenes wandering around the ASX with a lamp. I remembered from earlier mag TMI images the old theory that Antler might sit on the east limb of a north plunging syncline fold? Note the TMI Mag scale top-left... Log scale, with green at <2nT and orange starting at 92nT, and everything above 300nT pretty in pink (except for colour fading outside the interp Antler host unit to emphasise their early interp). A lot of magnet units in the image, can hardly tell Antler is a lot more magnetic than most.
So when you want to emphasise the highest magnetic units in a map, just change the scale to suit. Below is NWC release from early project acquisition days with green starting at 165nT, orange at 212nT and reds around 300nT. This is old 1960's data, different to more detailed NWC survey above, but by lifting colours up the scale we see less of the 'geological units' trend and more of the 'target highs'... At higher nT magnetic susceptibilities, NWC recognised back then, that what has now been named Bullhorn looks very similar to Antler. Of course, they didn;t own the tenements and so it was never mentioned again until an access deal was done.
Yesterday's release with more high-res mag data is a cross between the two above really, with just enough colour at high nT readings to reveal some lithology, while still making Antler and Bullhorn look like bullseyes (note no nT scale provided for investors reference which is naughty). Hard to tell at such a geographical small scale provided, but you can see the Antler Host Unit striking SW, then almost WSW, then more SW again past the Bullhorn IP chargeability high (yellow circle). Also clear imo, is the non-magnetic (blue)hornblende gneiss unit that separates the Antler Host Unit from the 'look-alike' biotite gneiss unit west of the Antler biotite gneiss unit. It's more obvious in the first image above, but no doubt imo the Bullhorn Mag High is part of a separate unit west of the Antler Host Unit.
Simply change the colouring scale and presto, you can make almost any data look like a target and keep the punters happy. Let's consider Bullhorn, not a 'coincident mag-IP' target so not really an Antler look-alike. A semi-coincident mag-Ip target in a different but still prospective unit to the west, and semi-coincidence is still high priority in the world of geophysics. Antler IP Chargeability at 100m depth slice below from 2020 release has a different scale to yesterday's IP images (
), designed to show Antler as a red-pink bullesye above 12nT... Antler is a truly Mag-IP Chargeability coincident bullseye near surface.
Antler IP anomaly moves west with depth due to the 60deg west dip of the Antler Host Unit as NWC stated. I don't believe the Antler Fold Nose theory because drilling to 1km depth has shown that the Antler Host Unit keeps dipping fairly consistently way past where it would have to fold around if it was the same unit as Bullhorn is hosted in couple hundred meters west (as shown by MRE outline projected to surface).
Bullhorn IP anomally (yellow circle from 250m depth slice copied to other images for reference) is virtually vertical... so no dip which is possible but unlikely only 300m south of the well drilled Antler Host Unit. So Bullhorn is a vertical IP anomaly that doesn;t start until ~200m depth, off-set from the Bullhorn magnet unit by 200m or so, which in all probability also dips west with the Antler Unit? Same, same but different as they say in Thailand...
That the IP anomaly is located on the actual Antler Host Unit is a plus imo, despite not being coincident with the mag anomaly. Being a vertical IP body is a negative given an VMS deposit will parallel the lithological unit dip, not that the lithology couldn't have been folded vertical in this deformed area. There seems to be quite a but of structural action evident in the new mag image around Bullhorn IP, which may have caused the IP chargeable alteration instead of primary VMS deposit alteration? Who knows until they drill it...
It's feeling more feeling bull than horn to this jaded geo, but I don;t mind any half decent target under the shadow of the headframe...
GLTAH
