“However, from my review of other Braemar iron projects, it is the red/dark red where the iron is and nothing where the green and blue is”
Concur. Dark red colours on the magnetic anomaly at both the Grants iron ore deposit (1.16 km
2 surface area) and the Grants Iron Ore Basin (the dark red is ~70% of the 17.1 km
2 surface area) show the location of the
magnetic iron formation in the sub-surface.
Variations in the Earth’s magnetic field respond to the intensity of magnetisation, which is controlled by lithological factors, principally magnetite content in the ground.
View attachment 1162308
The extract above of
RTP Magnetic imagery is from the ASX release dated 20 June 2018 (page 4). It is equivalent to selecting
Total Magnetic Imagery - TMI RTP in SARIG.
Cooler colours (such as blue) apparently indicate lower values and warmer colours represent increasingly higher magnetic intensity values.
“In the case of Grants, is it the case that the basin itself has the iron, and what's in the basin has no/low iron content”
From page 26 of the 2017 Annual Report, the Grants Iron Ore Basin was described as a large 10x6 km iron ore basin comprised of a thick sequence of almost flat-lying
Braemar Iron Formation.
Exploration for iron ore in the Grants Iron Ore Basin has largely been driven by the targeting of the dark red colour of the aeromagnetic anomaly to date, including limited RC drilling at the very western tip of the Grants Iron Ore Basin (highlighted on the extract above: the four small yellow crosses).
Reconnaissance drilling across the Grants Iron Ore Basin will be critical in establishing the geometry and grade distribution of magnetite iron ore within the target area.
Havilah has said it will be looking for areas of higher-grade magnetite iron ore, where the sedimentary depositional conditions were particularly favourable.
“Therefore, the mine would go around the outside circle of the basin as opposed to mining the blue/green inside the basin shape”
For now, I will assume so.
Once drilling starts, it will be interesting to see if the geological form of the Grants Iron Ore Basin iron ore resources is the shape of a ‘donut’ as Dr Giles refers to it.
Normally, the geological form of Havilah’s defined iron ore resources within the Braemar iron region is relatively simple, characterised by gently dipping slabs with the Maldorky deposit displaying some folding and shearing, as follows:
Geological interpretation (Grants iron ore deposit) from page 5 of ASX release dated 5 December 2012
The Grants iron ore resource is hosted by the regionally extensive
Neoproterozoic Braemar Iron Formation. It is normally steeply to shallowly dipping and may be up to 200m thick, comprising multiple iron formation and interbedded tillite horizons.
The sub-horizontal nature of the deposit and keel shape of the
Braemar Iron Formation at Grants is interpreted to be due to preservation (or formation) of the deposit in a trough in the older basement rocks.
Geological interpretation (Maldorky iron ore deposit) from page 6 of ASX release dated 10 June 2011
The Maldorky iron ore resource is hosted by the regionally extensive
Neoproterozoic Braemar Iron Formation. It is normally steeply to shallowly dipping and may be up to 200m thick, comprising multiple iron formation and interbedded tillite horizons.
The sub-horizontal nature of the deposit and apparent thickening of the
Braemar Iron Formation at Maldorky are interpreted to have resulted from the combined influence of tight drag folding and shearing.
Acquisition of this key mineral tenement (EL 5393) only occurred during May 2018.
This final piece of the puzzle provided Havilah with 100% ownership of the Grants iron ore deposit and the entire Grants Iron Ore Basin for $75,000 cash and a 1.25% royalty (to Exco and Polymetals) on all minerals produced from the EL 5393.
Cheers
These are only my random (weekend) thoughts and it does not constitute investment advice. Before acting on any information you read and before making any financial or investment decisions, you should always consult your advisor(s) or other relevant professional experts.
HAV fanboy: still drinking the Kool-Aid 
(20min delay)