Ann: Carbonatites Deliver Thick, Near Surface REE Results, page-105

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How I hate, beancounters, mine geos and resource geos/analysts. [LOL Tends to be mutual but without the each other not much would happen]. They take the fun out of what looked so good in the first few holes. Reality bites when trying to convert those holes into a mine...or not.

Off hand I can't think of too many deposits where the first hole was obviously the discovery one.
Kidd Creek in Canada 1963 comes to mind. Booming geophysical anomaly (graphite related) but 200+m of 8-10% Zn/Pb Cu in Hole #1 through the entire anomaly. They locked the drill crew on site and went on a staking spree. Still mining, I believe, after ~60 years, some 150Mt and down to 3000+-m

Many others came from when tripping over a Broken Hill, Mt Isa, Sudbury or Butte etc etc was possible..sometimes literally. Still possible
Olympic Dam took around a dozen holes though WMC were pretty sure by then (1970s). 10Bt now subject to economics etc.

CHN's Julimar was, in hindsight?, a first hole discovery. The initial high grade zone hit at Gonneville is now merged into a larger lower grade bulk tonnage in multiple zones. Still in the hands of the likes of @2ic as to what will happen if ESG issues can be sorted to everyone's satisfaction. Easier perhaps in the Gascoyne than on the outskirts of a city.

Yin, while small, probably counts as well.

Back to Mangaroon and Carbonatites/Ironstones.

Looked at the article - Link to article mentioned. Google 'Ni Tb mineralisation in Russia' - geosciences if doesn't work.

The bolded numbers refer to papers cited./listed in reference section.

Carbonatites are defined in the International Union of Geological Sciences (IUGS) system of classification as igneous rocks containing more than 50 modal percent carbonate [1]. Varieties of carbonatite are named based on the dominant carbonate mineral [2]. They have been chemically classified according to the percent by mass of CaO, MgO, and FeO_T and MnO [1], which has an evolutionary aspect as well. Most of the known carbonatite complexes have a common scheme of carbonatite genesis, whereby early calciocarbonatites were replaced by magnesiocarbonatites, and ferrocarbonatites, as the most recent [3]. The latter are considerably affected by carbo(hydro)thermal-metasomatic processes as they develop [4]. In general, carbonatites account for more than 50% of global rare-earth elements (REE) resources, which include Y and La-Lu [5]. REE enrichment is “most commonly found only in the latest and most highly evolved parts of a carbonatite intrusion” [6]. The accumulation of REE in late carbonatites is assumed to be controlled by fluid activity [7,8,9,10,11,12,13,14,15,16]. Such a surplus in articles reflects a keen interest in REE occurring in late carbonatites. More than 99% of the world’s niobium (Nb) is also known to be associated with carbonatite complexes [17].

Pretty good summary of a complex range of intrusives. Gets more complex from here.

The portions highlighted give a hint of processes that may have occurred for C1-5 and associated ironstones. [C6 and 7 and perhaps others will be confirmed in due course].

This section of C3 may represent the replacement process.



Replacement with Ferro or a different pulse of carbonatite +- syenite. Would be some clues from the drilling but would need detailed studies.

The ironstones are envisaged as a late stage aspect of the emplacement of these carbonatite plugs with weathering processes converting the near surface ferrocarbonatites into the ironstones. That process is related to what is seen in the above section though perhaps with a less altered source or some less concentrated variant.

At depth (on the section above) bulk grades seldom exceed 0.5% TREO (individual assays may be significantly higher or lower but no details announced). Still the bulk grade can be compared to fresh rock at Yin where grades are often >1%. The concentration effect for REEs in the "latest and most evolved parts of the intrusion"

The supergene (DRE terminology) looks like a mushroom extending outward from the ferrocarbonatite. The magnesiocarbs do not appear to have any input into the supergene zone.
[Hole 87 ends in syenite. TREO grades don't appear to reflect any lithology change - again this would be available from more detail data which, quite correctly, is not within the scope of the broader announcement.]

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I have used the blind folk and the elephant tale in the past on HC. Still very pertinent.

"In some versions, they come to suspect that the other person is dishonest and they come to blows. The moral of the parable is that humans have a tendency to claim absolute truth based on their limited, subjective experience as they ignore other people's limited, subjective experiences which may be equally true." Sound familiar??


A better consensus can be reached by sharing observations. No one person is likely to be completely correct (except @2ic - sorry couldn't resist, but I suspect as more data become available your skill sets would come to the fore)

Thanks for the reply @copperroad. I get a better feel where you are coming from.

Do you reckon many people would fully understand when most sentences need a paragraph to clarify/explain what you were meaning? Even after that I have more queries though most have to do with conflating and assuming or not defining the limits of what is being discussed.

For example define "too Early" For C3, carbs, ironstones, mangaroon, DRE?. Have a different area in mind and there will be near automatic disagreement.
An announcement for 90 holes into the carbs seemed, to me, what was being discussed not the broader project. My bad if it wasn't.


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