CRACKING THE PROSPECTING CODE:
WHY IS THIS PARTICULAR IRON-OXIDE RICH QUARTZ VEIN so interesting and an EXCELLENT indication that this is VERY RICH IN GOLD?
In this particular area, the country rock (the main rocks that are all around), is a type of rock that is a very 'boring / dull / uninteresting' looking rock. It is pale yellow/creamy in colour (geology name is: Rhyolite). It is NOT normal to have these IRON-OXIDE RICH QUARTZ VEINS....
This iron veining has obviously happened at a later time to the original rocks (it's younger) and has been 'intruded' into the country rocks along some fracture/fault planes (cracks).
When we see these 'foreign' looking iron-oxide minerals that are a GREAT CONTRAST IN APPEARANCE to the surrounding rocks, it's a HUGE indication that gold can also occur, especially when it's associated with quartz veining.
In this particular area, there are a lot of small nuggets scattered in well defined 'patches'.
The iron-oxides portions of the veining generally 'rust' away and decomposes MUCH faster than the surrounding/hosting country rocks and often these veins can be almost completely gone, with no evidence of where the nuggets have 'mysteriously' come from....... and that's when some interesting ideas about the source/origin of the nuggets can be inferred. ;-)
It's also good to note that when we took some of this iron-oxide vein minerals back to the shop, then crushed and panned in,..... lots of fine gold in the pan. Nothing that our SDC-2300 could detect as all the gold was fine, dust gold.
A good example of knowing what rocks / veins are worth sampling and crushing.... veins that look VERY different to the surrounding rocks, especially if these veins also have quartz in them.
Here's a great example of a more 'traditional' GOLD bearing quartz vein that is HIGH GRAGE. Notice the high contentment of Iron-Oxide veining that has 'post-dated' the original quartz-veining,.... in other words, the original quartz vein had NO GOLD in it and all the gold was introduced into the quartz vein LATER as a 2nd event which involve iron-rich veining. To get the gold veining does not always require a lot of quartz veining the be present first.