Good to see all these geophysical surveys and the recent AEM...

Good to see all these geophysical surveys and the recent AEM Channel 35 data.

However, there are a number of things that have me somewhat puzzled about this area which I will put up for comment.   Hopefully won't end up with too much egg on my face.

I have often wondered how CZI picked out the Dione Horizon.  Previously it was probably defined by a combination of the magnetics and perhaps geochemistry.

Take a look and see if you can reconcile the horizon with the magnetics.  Some sections are OK but others are not obvious to me.  Magnetics can be processed in many ways and perhaps the first/second vertical derivative or some other iteration makes the Dione more obvious.

The AEM really picks out the southern limb of the Dione formation
STRUCTURE?

This early image shows a "synclinal" axis.   I suspect this may be a "typo" but is actually correct label but should perhaps be an anticline or some form of overturned fold.

Also the Mismas target is considered synclinal in this announcement.

How is this a syncline?  Standard labels for a syncline have the arrows pointing inwards on the legend.

Also in the absence of established stratigraphy the terms synformal and antiformal may be more appropriate.

The initial concept for Iapetus was this where the stratigraphy is shown as dipping north.  Hence holes 1 and 2 of the 2016 program were drilled to the south but showed the stratigraphy actually dips south.  Subsequent holes were drilled on a northerly azimuth.

Drilling at Enceladus shows a southerly dip as well.

Summarizing this data:

As mentioned above some form of overturned (and plunging) fold may be present as some variant of the annotated image below.

The target model used is Teena which is a synclinal structure but it should be noted that presence of the Jabiru Fault may be more significant genetically to the ore than the folding.  The ore bearing fluids travel up the fault and are sometimes deposited in favourable units.
Note the keel plunges to the east where it is over 1000m below surface at the tenement boundary.


ELECTRO MAGNETICS - AEM

The strong EM response of the southern limb of the Dione is IMO formational and less likely to be the host for economic mineralisation.  The discrete Janus and Mimas targets are correctly the higher priority.   

My experience has been with older style AEM where flight lines relative to stratigraphy can cause poor to confusing results especially in folded terrain.  This doesn't appear to be the case in the area of the Mimas/Dione fold nose but may have been a consideration in the interpretation of data.

There may be other possible targets from the surveys which are currently rated lower priority and not considered for budgetary reasons.


GRAVITY
The gravity anomaly IMO looks more like a response to some form of intrusive than something stratigraphic.  NO REAL BACK UP FOR THIS STATEMENT.  Just the impression I get from the shape of the anomaly relative to the Dione fold nose.



Geochemistry
Zinc is a highly mobile element in the weathering environment.  It is not unusual for it to be leached out of some levels of the weathering profile or be difficult to use as a targetting tool for drilling other than on a grid pattern.  The offset from the Dione Horizon is hopefully a good sign.

West Arunta exploration.
A lot going on at X17 which is well worth a few thousand meters of drilling.

Some of the science used so far is IMO a bit unusual and I wouldn't mind sitting down with company geo's to see why they come to the conclusions they do.  A lot of thought and effort has gone into the work and announcements so it is more likely to be my bad than theirs.

ABU/IGO are working on their Lake Mackay project some 200 Kms to the east and getting interesting gold and some hints of base metals from what may be similar stratigraphy to West Arunta.
BHP/CZN and others tested gravity/mag anomalies to the west of X17 with minor technical success I believe.

CZI has folks from WMC's days of discovery at Nebo-Babel.  Part of that exploration found gold at what became Karlawinda and Tropicana.  The real biggie for WMC was Olympic Dam found by the wrong model and persistence.

This is real frontier exploration at the moment and whether or not the targetting is correct is a moot point if a good deposit is discovered.

CZI are going to drill so just a bit of colour and geo-poetry for the weekend.

GLTAH