What to look for when panning and detecting

Prospecting Australia

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just starting out and have decided to go out mid august for the first time so this information is greatly appreciated thanks alot
 
Thank you so much for the info that you have supplied so useful for someone like me who has no idea at the moment.
Ted
 
Awesome info. Im really enjoying these newby threads. Im trying to act like a semi permeable membrane and absorb everything I can :p
 
Fantastic info definitely appreciate the links to reading the journals etc. awesome work guys well done
 
There are several signs that I did not take into account. It's a shame, this means that I missed one interesting thing, it's good that I remember its approximate location.
Post with notes on the search, useful, I will print it and save myself :)
 
Im planning a trip to dunolly/Kingower/Waanyarra soon and was wondering and still learning. In the state forests can If i camp anywhere do I have a chance to find gold? Im thinking of almost throwing a dart and picking a spot. Or is the gold only in gullys etc?
 
Diggerdude said:
Greenstone= jade?? Don't reckon that's correct. Maybe in nz.

Most of the greenstone belts associated with gold in Aus are ancient basalt. ( it is not an actual rock type but rather a term used for metamorphised belts of basalt and granite ). They are often heavily folded from continental movement and intruded by granites. Because of there extreme age they often have lots of cracks that have been filled with quartz, long after the basalt formed. So it also has nothing to do with the temperature of the rock. This is where you often get gold disseminated though the greenstone near the contact with quartz.

Hope this clears it up for you all.

DD
Partly correct in both the original and the comment on it, but mostly only for Western Australia. Although nephrite is sometimes referred to as greenstone, the meaning in the list is almost certainly metamorphosed basalt (there is no particular association of nephrite and gold). The comment re metamorphism is correct, except it is never metamorphosed granite, only rocks like basalt. However be aware that this association with greenstone (in Australia) is almost entirely relevant to Western Australia only (the Yilgarn and Pilbara, where almost all gold is related to greenstone - but not to granite - so a valid point.

The "temperature" comment actually has more than a grain of truth, depending on what is meant. Fresh basalt does not usually contain gold, it requires burial (higher temperatures and pressures) to convert it to chlorite-rich rock at intermediate depths, and amphibolite at great depths (we call both greenstone). The conversion process involves driving off water from the rock for amphibolite to be created. This hot water probably dissolves silica and gold. This then pumps up fractures to shallower depths, and deposits quartz and gold in fractures, most often in the chlorite rocks, sometimes deeper in the amphibolite, but virtually never in fresh basalt.

So to re-word it. If in the Pilbara or Eastern Goldfields of Western Australia, look in greenstone (chlorite and amphibole rocks, which are green), not in granite or fresh basalt (but note that some greenstone if little-altered can still resemble basalt, but can contain gold - really need a geo in that case - the trick being that all that is Archean in age is now greenstone, and basalts are Cenozoic or Mesozoic and quite rare in those areas.
 
DeckyDan said:
Mystyk59 said:
A mate of ours posted this on our page on facebook and i thought it might be useful for some of those starting out :cool:

1. etc etc
All great info without the boring bits, great job!

From the point of view of a gold exploration geologist, a good practical list that is difficult to fault.

Just a few comments - the first comment (above) relates to greenstone. Good advice for Western Australia and of very limited to no use in most of the eastern States. While a lot of the world's gold comes out of greenstone, half came out of the Witwatersrand where none is in greenstone (ditto for 95% of production in Victoria, most in Nevada, NSW etc.). In Australia, it mostly works just in the Pilbara and Eastern Goldfields. For example Victorian gold is mostly in sandstone and slate.

There is no evidence of a relationship to agate in Western Australia (but chalcedony usually litters the surface in areas underlain by greenstone, which is probably where this idea comes from). So it helps you know when you are on greenstone not granite in Western Australia, but is not a direct indicator of gold. It has nothing to do with it being hot enough to form gold, nor is the colour related to temperature - the WA chalcedony is not formed from hot water in the main. There are other areas in the world (eg Nevada, North Island NZ) where high temperature chalcedony occurs and gold is directly associated with it - then it is a direct indicator of gold. The colour is irrelevant although most is white or fairly clear, usually in bands like agate. However it is rare to find such ore bodies in Australia - a lot in Queensland, very few in NSW, nothing of any real interest in Victoria (white quartz is the main carrier in those last two states). Rose quartz is not useful as a general indicator anywhere in the world that I am aware of, and its colour is not temperature-related (no doubt there will be an exception somewhere in the world, but it is not a general indicator). It is true that a lot of black quartz is formed by radiation damage (however unfortunately it is not a very useful indicator of uranium because it also occurs in many areas without uranium - and much black quartz is due to petroleum inclusions not radioactivity).

So overall an excellent list, the main issue being that it was probably compiled by someone working in Western Australia where it applies best. And be careful of the significance of "agate" (chalcedony) even there. Different indicators apply in different parts of the world and Australia, but greenstone is good (mainly in WA) and for detectorologists and panners quartz is a very good indicator in most of the world (but not all - most gold mined in Nevada nowadays is not in quartz veins, and the same was true in the Witwatersrand - but is too fine to detect or pan anyway - even there, the stuff you can detect or pan mostly comes in quartz or chalcedony veins).
 
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