SGQ in 2020, page-131

Question for the geologists out there.

I thought the sulphides were getting massive by concentrating mineralisation along the way and then sinking down in embayements of the basalt at the mafic/ultramafic interface.

The question is, how do you get 17m of high grade mineralisation at only 37m like in MAD71 ? Is it remobilised from deeper through geological deformation ? I would assume it would take a lot of "original" mineralisation to get this, so how does it happen so shallow ? Did it "accumulate" on the way as it flowed up ?

Just out of personal curiosity.
Cheers.