RE: DOUBLE DIGIT BLUE!!! 🔵 🔵10 Oct 2025 19:22
ChatGTP answer re surprises.. Basically all the options sound fantastic..
🪨 2. Possible “surprises” at the bottom of the breccia
(a) Feeder dykes or intrusions
You may find porphyry dykes, lamprophyres, syenites, felsic domes, or even ultramafic intrusions feeding the breccia pipe.
These could host high-grade gold, sulfide-rich zones, or even rare-element mineralisation (Mo, W, Te, REE, U).
(b) Boiling zone or high-grade “root zone” gold
The bottom few hundred metres of a gold breccia often contain:
Coarse quartz–sulfide veins, electrum, tellurides, and native gold.
Replacement textures (sulfides replacing breccia matrix).
This is because pressure drops and temperature gradients cause gold to precipitate near the feeder.
(c) Hidden intrusion or magma chamber
Sometimes a dome breccia caps a hidden intrusive cupola (granite, diorite, rhyolite, etc.).
These can be sources of porphyry-style mineralisation — Cu, Mo, Au — beneath the breccia.
(d) Alteration zones
Deep alteration halos — potassic (K-feldspar, biotite) or sericitic zones — often develop here.
These can point to porphyry or epithermal transitions, very useful for exploration targeting.
(e) Unexpected rock types
Some breccia “roots” cut into older ultramafic or metamorphic basement — possible hosts for:
Shear-zone gold
Base metal sulfides (Cu, Zn, Pb)
Occasionally, carbonaceous or graphitic zones that act as redox traps for Au.
(f) Exotic or mantle-derived components
If the breccia has deep magmatic origins, you might find:
Mantle xenoliths, pyrope garnet, or Cr-diopside — sometimes hinting at kimberlitic or lamproitic affinity.
These are the rare cases where diamond indicator minerals can appear.
However, that’s only if the breccia was emplaced by deep mantle-sourced magmas, not normal hydrothermal fluids.