Hi @BienSuerte,
The GMN Ann 23/7/2024 brought into focus a collection of tenements in Ceará that have not previously attracted attention. The idea that there might be an IOCG resource in/near a GMN tenement definitely raised interest. This area has many GMN and FMG tenements. The announcement maps 4 areas within it. All of the tenements have nominated "Copper" on lease applications and date back to 2021.
The IOCG ore bodies are created by the application of heat to a mineralised body containing copper. Sulphur must be present to promote partitioning/enriching of the copper minerals, and reduced iron to scavenge any oxidisers (like water) that would disrupt the process. Granite intrusions can act as the heat source, but this area of Ceará is awash with K-Granite. Is there anything really special here ?
Well yes there is. A Thorium trend runs from SW to NE. Its presence indicates that a great deal of (cyclical ?) heat was applied at some time. The same trend also holds some Uranium.
The kmz below contains the boundaries of those tenements, the boundaries of the areas mapped by announcement, the Thorium and Uranium Radiometric maps, the Magnetic Field Anomaly Analytic Signal map (indicating the presence of reduced iron), and some points of interest ( Google Earth URL ).
Definitely some exciting prospects here !
GLTALTH
Disclosure : not an FMG SH
PS1: FMG tenements have been included in this post because the order and proximity of lease applications indicates how priorities have been discovered over recent years and IMO still apply.
GMN ~ Iguatu, Ceara, Brazil (20240728, v001).kmz.txt
PS2: Some metals and sulphur can readily change their valency. The temperature dependency of those changes can lead to de-homgenisation of initial mineralisations. Mineral species (like those of Copper and Nickel) that melt or change density independently of others will eventually disaggregate and possibly concentrate.
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