Ann: Mineralised carbonatites intersected over 3.5km -West Arunta, page-89

Some hints from the "known" to unknown.

Presented the 3 carbonatite zones from 3 holes. No comment on the others (2, 5, and 6 anyway - 3 4 and water bore at 2 probably didn't get far into fresh rock if at all)

If holes 5 and 6 do not have significant carbonatite then Hole 8 may represent a dyke adjacent to the Elephant Island fault which may "blow out" somewhat to the east over the 1.5 Kms to hole 7 and hopefully further east.

Crudely in plan view

ENR MT WEBB FULLgswa geol LEGEND PLUS GRAV OVERLAYS.pdf

Red outlines rough gravity high interp
Light Blue carbonatite - South margin constrained in 7, perhaps by 5. North margin by 8 with a possible faulted contact but open in 7.

Surface mapping shows resistant quartzite outcrops variably over the Aileron Luni etc area so there is a possibility some of this was intersected in the weathered zone along with some conglomerates.

Ultramafics are commonly more dense and magnetic than granitoids or sediments. Ni/Pge potential?? If 6 into ultramafic then could get interesting - low potential for this but one possibility.

A schematic sectional view through 5 6 8


Holes 5 and 6 tested geophysical anomalies quite well. Gravity perhaps a little better than the magnetics.

Zooming in on Hole 8



If hole 5 had carbonatite in it then most likely would have been mentioned. An assumption which probably applies to Holes 6 and 2 but remains that until confirmed or shown to be wrong.

The posts above about the areas of possible enrichment came in while preparing the above diagram.
Sulphidic clays and ironstone were why I highlighted the zone above but the area of ferruginous and limonitic clays noted by @2ic above will be of interest as well.
The transition of weathered to fresh in Hole 5 may be useful for grade.

The extent of '?fenitisation' around the dyke in EAL001 suggests a relative large alteration halo. Where does the Cu come from that initially encouraged an IOCG model.?? Strong hematite alteration as well?? The unknown...

Caird section with drill hole traces - schematic.



Hole 2 was shorter than planned (errata TD 463.3). Appears to have tested the geophysics well. No comment and stopping 'early' suggests a technical success to confirm the geophysics. Carbonatite in any of 2, 5, or 6 would probably be material information.....From the JORC appendix.

EAL002, EAL005 and the section of EAL001 reported has been logged in detail by Encounter Geologists with lithology, alteration, mineralisation, structure and veining recorded.Detailed logging for all other holes, including EAL007, EAL008 and the remainder of EAL001 is ongoing.

====================================
EAL001 is 2 Kms west of hole 8 and 3.5Kms from hole 7. Could be a fault controlled dyke >3.5Kms long and from 10s to ??wide (at least 150m at hole 7). Neither gravity nor magnetics seem to give a strong clue about a direct connection - too narrow in places?

Combine with Luni and P2, REE at Shackleton and there is an emerging carbonatite district, as suggested by several posters, to the north of Lake Mackay.

Luni - strong gravity no/minimal magnetics. Perce almost no magnetics and strong gravity?
Lots of interesting targets.- A good start.