Its important that people posting here can discriminate between the collection of data, and the interpretation of it and what the XRF can and cannot detect.
Quantitative geochemical data can be from traditional assays, and also from portable XRF, and assays can be from rocks at surface or from drill cutting samples or drill core down-hole. In general most here get it that from some target elements (Cu and Ni for instance) can be directly detected by XRF or by traditional assays with reasonable accuracy, while other precious metals cannot be reliably detected by XRF because of their rarity and stable outer electron shell (Pt Pd and Au), this is why gold explorers don't routinely use XRF's to directly detect gold in drill samples, the only way is getting a decent sample size and a real lab assay done. XRF's can detect a wide variety of metal and transition elements quite quickly and in some cases almost the same accuracy as a traditional whole rock assay, some of these elements are worthless but are associated with other more precious metals so can be "indirect" proxies or "pathfinders" for the stuff you are looking for. Elements such as As and Bi are famous for their pathfinding ability for some types of gold deposits.
Its important to distinguish which types of target mineralisation at Broken Hill are visual and which aren't, in RC chips and in drill core. In high enough concentrations say between 1% and above, disseminated copper chalcopyrite and nickel pentlandite sulphide minerals are visual but often mixed up with worthless iron sulphide mierals such as pyrite and/or phyrrotite, and they would have a chance to guess the copper and nickel grades, and even confirm with an XRF before sending to the lab but for gold or PGM metals, because they are down in the parts per million range if they are occurring without base metals then they might be impossible to spot visually, and the XRF is no help with those elements either, so they would be relying on lab assays.
The geochemical ratios that Mike Jones and IPT are talking about is getting a bunch of geochemical numbers form many elements of many outcrops and drill holes and looking at not only the proportion of Cu Ni Pt Au and Pt in all these geographically distributed samples but also considering other ratios of other elements that aren't particularly valuable but do give clues about the geochemistry of the rocks, say for instance the ratio of iron to magnesium, or using other pathfinders maybe such as Co V Mn etc etc and throwing all of these different ratios on scatter plots and seeing if there is a direct relationship between any of these elements and the samples from the higher grade Pt Au Ni Cu zones already drilled. Once they think they have a good bunch of pathfinder elements and/or ratios of elements that might show "prospective" rock geochemistry for mafic Ni Cu Pt Au style mineralisation then IPT can go out and collect a bunch more of geochemical data (this is where the XRF comes in handy) from outcrops, and from all the other drilling nearby, plot it up on a map and direct further sampling and drilling to these areas. The one thing you want to watch out for is you want pathfinder elements and ratios of elements that don't disappear in weathered rocks at surface, but are a bit persistent in surface rocks, otherwise you cant extend your geochemistry data set coverage onto the outcropping surface rocks. You don't want pathfinder elements that go into solution and disperse with weathering into gullies or flats or preferentially collect in some soils because you are trying to find the source of these valuable related metals, not where they get washed out into during normal weathering processes.
Someone else asked about additional permitting required for additional drill holes, most state regulators now want companies to specify how many drill holes they have planned and where and if the exploration company want to drill additional drill holes then the regulator usually needs to see a new or amended proposal of additional drilling planned, nothing unusual in that but it does reduce the flexibility of companies to follow up quickly if they discover something visually encouraging and drill additional holes around it. Unfortunately most regulators now won't accept vague proposals to drill a bazillion holes "somewhere" in this area anymore, and they want specifics about hole locations and depths so when your plans change you have to submit new or amended proposals, just part of the regulators justifying their own existence. This is all reviewed and permitted by people who have never done mineral exploration, and usually never seen a drill rig in their life... I'd say what has happened here is that IPT have done their geochemical ratios and pathfinder work and want to drill some extra holes in new places and are just awaiting approval for these additional holes.
Losing their big batch of assays last month mean that they are "flying blind" a bit about which of their drill holes have been successful and which have not because they have had to go back and re-sample if possible and then wait for the lab assays.
IPT Price at posting:
2.3¢ Sentiment: Hold Disclosure: Held
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