Having worked a short stint at the Argo gold mine, Goldfields - St Ives (1Moz+ production and closed now), I can readily imagine how difficult it would be to interpret what is going on at Bombora from shallow wide spaced drilling.
All I can say about similarities at the moment between the two (Argo/Bombora) is they are both in differentiated sills with apparently complex distribution of gold.
At Argo there were at least the A1, A2, B1, B2 and L3 mineralized structures at multiple orientations. These probably required an open pit and detailed drilling to be defined. Bombora will have its own unique structures that will need more detailed work to refine if results warrant - probably will.
I don't recall lamprophyres at Argo but I have seen them in another large deposit. They are readily recognizable but were seldom spatially close to the auriferous lodes at Sunrise Dam. As noted by BRB they do show up at certain gold deposits but whether this is because of the presence of drilling information (economics generally preclude drilling to see if lamprophyres are present or not) or more likely some relationship to the structures that also source gold deposits I don't really know. Does anyone know if they are found near Ni deposits away from gold?
In fact lamprophyres were a bit of an anomaly at SD given age dating put them several hundred million years younger (2100Mya?) than the host rocks (2650+-Mya) and gold mineralization. The significance appears to be that lamprophyres may reflect some deep seated structures that were reactivated at various times in geological history.
Been following this fascinating discovery at Lake Roe - hence my interest.
GLTAH.
BRB Price at posting:
52.0¢ Sentiment: None Disclosure: Not Held
