Doug Stone, John Tully et al Maps - The Good, the Bad & the Alternatives

[user 4386]

Ok that makes sense but the way geovic labels some veins as 'QUARTZ_WORKED' and others as 'AURIFEROUS QUARTZ WORKED' seems to delineate that veins with an of attribute 'QUARTZ_WORKED' was worked for gold, but didn't have gold? Could that be the case? I just cant understand why they would have the two different attributes otherwise?

I am pretty sure there is no intended distinction. Quartz itself was only mined in about 4 small areas. And not in the Ordovician rocks of central Victoria, but in granites (which don't have gold in central Victoria). Obviously I don't know the maps you are referring to, but I am confident that you are making an unintended distinction. Maps were made by many different geologists.

What layer on Geovic are you referring to?

 

[Geepeezee7]

I am pretty sure there is no intended distinction. Quartz itself was only mined in about 4 small areas. And not in the Ordovician rocks of central Victoria, but in granites (which don't have gold in central Victoria). Obviously I don't know the maps you are referring to, but I am confident that you are making an unintended distinction. Maps were made by many different geologists.

What layer on Geovic are you referring to?

Geology>Interpretations>State Wide Data (1990-2006)>Geology 100k>Geological Lines and Faults 100k

 

[user 4386]

Geology>Interpretations>State Wide Data (1990-2006)>Geology 100k>Geological Lines and Faults 100k

That is not standardized - it is simply summarized off maps by many geologists, using the terminology used by each.

Perhaps a screen shot of an example where both tyerminology is used?

 

[Geepeezee7]

That is not standardized - it is simply summarized off maps by many geologists, using the terminology used by each.

Perhaps a screen shot of an example where both tyerminology is used?

Not standardized. That makes sense. Here is the screenshot. In the example, the full reference is two different map makers. I suppose Marlow doesn't use the term 'auriferous quartz worked' just 'quartz worked' whereas Edwards does.

 

[user 4386]

Not standardized. That makes sense. Here is the screenshot. In the example, the full reference is two different map makers. I suppose Marlow doesn't use the term 'auriferous quartz worked' just 'quartz worked' whereas Edwards does.

Too small to read., but almost certainly as I have said. I would not waste time making a distinction that is meaningless. Other than the very few mines on very pure and transparent radio frequency crystal quartz, there were no quartz mines (alone). There did not need to be because there were millions of tonnes of nice white quartz pebbles around deep lead shafts - now micronized for sale.

 

[Geepeezee7]

Too small to read., but almost certainly as I have said. I would not waste time making a distinction that is meaningless. Other than the very few mines on very pure and transparent radio frequency crystal quartz, there were no quartz mines (alone). There did not need to be because there were millions of tonnes of nice white quartz pebbles around deep lead shafts - now micronized for sale.

View attachment 7819

Let me try that again...^ you should be able to click on the image and zoom in.

Sure I understand what you are saying, but I am not talking about mines, i am talking about veins. Surely there were loads of quartz veins which didnt host gold, which is why the distinction exists?

Side question; can one detect in public land which is designated a 'plantation' in VIC?

 

[user 4386]

No, there is definitely no distinction being made. I know those reefs on the spreadsheet and those that say only "Quartz worked" were all worked for gold. Some are well known gold mines.

Don't know answer to last question - I did not even know that plantations existed on public land!

Not sure why you are using the "Geological Lines and Faults 100k file" - it seems to be the hard way to do it (and I am unclear about your aim). Are you interested in detecting or in making maps (I have already compiled all auriferous reefs in Victoria digitally at 25K scale)? Here is a reduced version of my 25K compilation for the area you are dealing with (mine are mostly accurate to about 50 m or better on my digital files), Crosses are reef mines where I don't know the orientation of some reefs, otherwise the lines are auriferous reefs. Of course they are named on my 25K originals. I did it using the "mineral occurrences" file and making subsets of it to only record hard-rock (not alluvial) gold mines, combined with registering and tracing from all geological and mining maps ever published going back to 1851 and up to the present. Of course I have roads, streams, contours on my plans - this is a simplified reduction (and no my maps are not available - I do this for a living)..

 

[user 4485]

Side question; can one detect in public land which is designated a 'plantation' in VIC?

Any areas marked "plantation" on topo type maps I've seen generally seem to be private farm land or active state forest logging areas (which may be accessible at times of inactivity).

 

[user 4386]

Any areas marked "plantation" on topo type maps I've seen generally seem to be private farm land or active state forest logging areas (which may be accessible at times of inactivity).

Same here

 

[Geepeezee7]

No, there is definitely no distinction being made. I know those reefs on the spreadsheet and those that say only "Quartz worked" were all worked for gold. Some are well known gold mines.

Don't know answer to last question - I did not even know that plantations existed on public land!

Not sure why you are using the "Geological Lines and Faults 100k file" - it seems to be the hard way to do it (and I am unclear about your aim). Are you interested in detecting or in making maps (I have already compiled all auriferous reefs in Victoria digitally at 25K scale)? Here is a reduced version of my 25K compilation for the area you are dealing with (mine are mostly accurate to about 50 m or better on my digital files), Crosses are reef mines where I don't know the orientation of some reefs, otherwise the lines are auriferous reefs. Of course they are named on my 25K originals. I did it using the "mineral occurrences" file and making subsets of it to only record hard-rock (not alluvial) gold mines, combined with registering and tracing from all geological and mining maps ever published going back to 1851 and up to the present. Of course I have roads, streams, contours on my plans - this is a simplified reduction (and no my maps are not available - I do this for a living)..

View attachment 7827

...No, there is definitely no distinction being made. I know those reefs on the spreadsheet and those that say only "Quartz worked" were all worked for gold. Some are well known gold mines...

Wow, there sure were a lot of auriferous quartz reefs.

...Not sure why you are using the "Geological Lines and Faults 100k file" - it seems to be the hard way to do it (and I am unclear about your aim). Are you interested in detecting or in making maps...?

I am interested in detecting for eluvial gold. I thought by using "Geological Lines and Faults 100k file" (which displays auriferous reefs) that I could use the reef locations + contours to hunt for eluvial gold. I am curious why you think that would that be the hard way to do it? I will add the "mines and mineral occurrences" layer though and make subsets of it to only record hard-rock (not alluvial) gold mines. A lot of the "mine depth" attributes are -999 though. It would be better to be able to delineate more of the shallower ones to work out which ones are on shallow ground, I notice there aren't too many under 1 metre.

...Crosses are reef mines where I don't know the orientation of some reefs...

Are they not shown on "Geological Lines and Faults 100k file" at all?

...(and no my maps are not available - I do this for a living)...

So.... uhh... can I have your maps? Then we can both do this for a living. Hey you never ask you never get, right?

Here is geovic showing me reefs in e.g. Wedderburn. I didnt have to trace all the reefs off the old maps. Its all there in geovic? It seems like you are doing it the hard way to me!?

 

[user 4386]

...No, there is definitely no distinction being made. I know those reefs on the spreadsheet and those that say only "Quartz worked" were all worked for gold. Some are well known gold mines...

Wow, there sure were a lot of auriferous quartz reefs.

...Not sure why you are using the "Geological Lines and Faults 100k file" - it seems to be the hard way to do it (and I am unclear about your aim). Are you interested in detecting or in making maps...?

I am interested in detecting for eluvial gold. I thought by using "Geological Lines and Faults 100k file" (which displays auriferous reefs) that I could use the reef locations + contours to hunt for eluvial gold. I am curious why you think that would that be the hard way to do it? I will add the "mines and mineral occurrences" layer though and make subsets of it to only record hard-rock (not alluvial) gold mines. A lot of the "mine depth" attributes are -999 though. It would be better to be able to delineate more of the shallower ones to work out which ones are on shallow ground, I notice there aren't too many under 1 metre.

...Crosses are reef mines where I don't know the orientation of some reefs...

Are they not shown on "Geological Lines and Faults 100k file" at all?

...(and no my maps are not available - I do this for a living)...

So.... uhh... can I have your maps? Then we can both do this for a living. Hey you never ask you never get, right?

Here is geovic showing me reefs in e.g. Wedderburn. I didnt have to trace all the reefs off the old maps. Its all there in geovic? It seems like you are doing it the hard way to me!?

View attachment 7836

Ha! No, I understand what you are doing - I did not realise that you are focusing on a specific area and thought you were doing it on a regional scale. But if you are focusing just on one or two goldfields it makes absolute sense. However don't forget to overlay no-go areas, private land etc (there is quite a bit around Wedderburn and Rheola). You will find that potential areas that you can go without permission are quite limited (but I find a lot of property owners are OK simply because you ask).

Again, mine depth is a bit irrelevant, That is more a measure of tionnes than grade - most detectorists want coarse gold and nuggets and that is quite different to tonnage - workings on some reefs that have good nuggets in soil only go down a few metres.

Yes, I use hard-rock mines on the min eral occurrence layer (an attribute) first but then register old maps and trace missing reefs (50% are missing in some areas but not a lot) - the Geovic data misses a lot of reefs. I have actually provided shaft info to Geovic myself - mining companies tend to map them as they explore and Geovic adds them as the data comes in - it is not all historical. Also shafts can be some distance from outcrop positions once you get down to detail ( usually not more than a couple of hundred meters) - you do not sink your deep shafts through the middle of your quartz reef or your mine becomes unstable once you remove the quartz reef. But for most purposes the shafts are quick and useful.

Uh...no

Good luck.