One thing that perhaps I didn't make clear in my initial post Thunder, is that I was purely referring to the prospectivity as far as as the MdP style of mineralisation goes, i.e. the thick, tabular, at surface, relatively uniformly mineralised, siliceous lithocaps.
One thing that's important to realise, is that these volcanic units (andesite and dacite agglomerates) aren't likely to be the
source of the mineralising fluids, but rather the material that facilitated the precipitation of the gold/silver rich hydrothermal fluids in the epithermal system.
It appears that there is something about the andesites hydrological and geochemical properties that facilitates the formation of both a) the siliceous cap rock and b) silver and gold.
Now, what I don't know is if the silver mineralisation occurred synonymously with the silica formation (i.e. happened together), or if it was the result of a second event entirely. I have no thoughts on that at this time and it's not really my area of expertise. It would be a good question to ask AZS geologist, as it will have implications moving forward.
As far as the primary source of the mineralising fluids is concerned, it is likely to be an intrusive magmatic body at depth - likely whatever is producing those IP anomolies we know exist. This is also likely to be where any porphyry copper is found - the thing that originally attracted AZS to this area.
Now, to your observation about Puerto del Oro, it looks like we have a completely different style of mineralisation here. A few quotes that highlight this from that annaouncement:
"Mineralisation is hosted in quartz veins and zones of silicified and iron-rich breccia. These zones extend for up to several hundred metres in strike length, and range up to 10 metres in width".
It looks like we have more of a vein and/or shear zone (notice the word breccia) hosted style of mineralisation here. Perhaps this is more of what we will see throughout the dacite terrain.
What that will likely mean - mineralisation will probably be refined to thinner, steeply dipping veins and fault/sheer structures, rather than wide, at surface, horizontal ore bodies.
That means it's going to be harder to find, but surface mapping of outcropping breccia and veining should help (and will be very important). It will also mean we will need to drill angled boreholes to intersect this stuff.
Another important thing will be taking into consideration the dominant local structure (i.e. dominant fault/shear orientation). This appears to be a NE-SW trend. This looks consistent with where the high grade zone has been identified by soil sampling at Puerto del Oro:
View attachment 142680
A look at the bigger picture shows this Ne-SW trend is clearly the dominant structural orientation:
View attachment 142679
The research piece Haplo posted yesterday also talked about some dominant near N-S trending faults - that looks more like what we've possibly got separating MdP and LB, however it's not on the geological map we've got here.
Anyway, more food for thought. I'm looking at a bunch of cross sections of the area and coming up with some more hypothesis'. Plenty to keep one pondering.
