The G/B area is so large, and underexplored, that I fully expect many different deposits to be discovered, some will be VMS, possibly MMS, and the list goes on. What I am attempting to do is characterize the origins of this particularly rich greenstone belt, and then work my way backwards to solve the mysteries of the localized mineralization as we receive the info ( which is always going to be much later than the company geos, putting us at a great disadvantage, nothwithstanding our "amateur" status.)

Something like a BIF is definitely sedimentary by the nature in which it was laid down. That is not to say that in the event of a back-arc rift that tectonics and volcanics were not at play: the very nature of some of the discoveries to date point to magmatics. I'm just chasing down clues here on the various properties in an attempt to understand just what it is that lies under the surface.

Here's a geological snippet that deals with cratons and greenstone belts, and while it does not apply per se with the region of Canada we are dealing with, it gives some good background info. Not to mention the G/B greenstone is exceedingly old, has undergone glaciation, and what could remain now could be the "stumps" or basement of mountains/volcanoes and magmatic deposits.

Cratons grow as plate motions move them about the surface of the earth and they run into other crustal plates. The North American craton is currently adding material along its western margin, where it is in contact with the Pacific plate along a long, linear zone of faulting called a subduction zone. Most of what is added is granitic, which is thought to form in the cores of volcanic arcs associated with the subduction process. However, lots of other stuff gets added in along with the granite. It is not uncommon for sections of oceanic crust (usually basalt) to get caught up in the accretion process and become wedged in between sections of granite. We call these inclusions of mafic crust "greenstone belts," and it is clear that this has happened many times in the past as the North American craton has developed into what we now see. The term "greenstone" comes from the color of the rock: the mafic minerals which make basalt black are commonly changed into a green mineral called chlorite as they are exposed to surface weathering processes. The result is a green stone which geologists cleverly call a greenstone. (It's brilliance such as this which justifies all the big bucks geologists are paid.)

Hope this helps clarify things somewhat...I'm still "playing" at geologist, and by no means do I even pretend to be one!