It is difficult without dips on the bedding but potentially its...

It is difficult without dips on the bedding but potentially its an antiform with juxtaposition of beds from west dipping reverse faults. This suggests E-W compressional event in greenstone belt wedge in a compressional orogeny. The felsic crytal rich tuff is a type of volcaniclastic rock ejected from a vent with a felsic magma e.g. rhyolite. The crystal rich nature probably suggests the magma contained feldspar phenocysts prior to being ejected. The tuff could be kilometers from where it was ejected. From my experience v'clastic rocks are generally poor hosts to MZ because they are ductile, although many factors can change this such as welding, grain size, silicification, alteration, porosity etc. And thats not to say some of the best gold deposits int he world arn't hosted in v'clastic rocks. The contact zones of v'clatic rocks with competent igneous rocks can be good hosts to MZ due to rheology contrasts. The only person that has the knowledge to comment on the relation of gold MZ with tuffaceous beds is the on site geologist. They may share no relation at all and the MZ is more structurally controlled with jasperoid veining/alteration along faults. I don't know though I don't follow this company. I hope this hasn't mislead you at all, take it with a grain of salt because I know nothing about the geology of the place. Ring them up to find out what is really going on.