This paper here gives you an outline of what EMs are trying to do - this picture comes from this article.
Resistivity (ubc.ca)
The purpose of my post in part was to also say the the term mafic/ultramafic is quite loose as the rock structures per se can vary in composition significantly as well.
Now when I talk about MLEM possibly not leading to what one thinks this Ann and the tables essentially say that -
b3517fa0-3b78-11eb-9b6c-6ed2e8d018c2.pdf (copyright link) - it provides a hypothesis and then drilling decided that some of the EM results were not great after all and note this Ann was just an example, as I could of used a few others. How good is the hypothesis also relates to how much soil sampling and the exploration techniques were used in combining the data to form the hypothesis but ultimately drilling decides anyway.
It would appear from subsequent posts to my post that the historical data seems to have some signatures, and I presume a soil sampling program is also on the cards here as well. Having said that, Julimar type signatures are nice but so are copper/gold discoveries in the area, which the Yilgarn is renowned for as well.
Before drilling, as I understood CHN, they did soil sampling (overlaying it on the EM results to strengthen the hypothesis) as well and sort to understand the chromite signature there to complement EM work at Julimar and therefore target drilling campaigns. (LTR certainly used EMs etc in targeting its inaugral campaign and had a mixed result in seeking a 'Julimar' albeit it did have some ok copper/gold minefralisation hits). .But tieing my posts together, after again refreshing my memory on Julimar, here is some comments around CHN's latest target at Hartog. Some relevant paragraphs are also below and they show how EMs, soil sampling signatures, any historical data is overlayed to form a 'hypothesis'and then target drilling areas per se:
Chalice identifies new EM conductors at exciting Julimar project - The Pick Online Magazine (the-pick.com.au)
and
and
In terms of the last paragraph, note the wide Siemen results btw. But the point is there are other signatures that need to complement the EMs data (soil sampling/chromite signatures) as EMs per se can be impacted by various factors so I wouldn't be definitive of a 'Julimar signature' is my point at this stage and basically who cares if you end up say finding copper/gold
In my post, when I talked EM's you have to make certain assumptions around what is going on in the results you receive, hence why any historical data in the area and nearlogy aids a hypothesis as well as the need for additional reconaissance work before drilling, but only look at links for information only. I think the Chalice link above is good for those who don't really want to get in the nitty gritty of exploration per se.
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4 Electrical and Electromagnetic Methods (berkeley.edu)
And now that you have indicated some of the historical data and assays and presence of chromite (be interesting at what PPM), after my initial post, well I will keep an eye out. Seems interesting in itself.
GLTAH here. Looks like they seem to like what the EMs are showing as well and hence the CR and I suspect quick move to drilling.
All IMO
(20min delay)