I agree. In some cases the forests had not fully re-grown and farmers had not dozed over things, so there was more for the old-timers to map.
Doug Stone, John Tully et al Maps - The Good, the Bad & the Alternatives
- Thread starter mbasko
- Start date
Help Support Prospecting Australia:
I have a Signal Dunolly map and a downloaded copy of that old geo map too (which i'd love to print, frame and stick on my wall one day! 
) so am somewhat familiar with both.
First of all this is the same scenario as was discussed with the Kangaroo Flat sample. What's posted above is one of the few (as in 4 or 5) surveys that the state government carried out at that level of detail, which appears to be around the 1:10,000 mark. The hero goldfields surrounding the town centres of Castlemaine, Ballarat, Bendigo and Dunolly received this level attention, but no where else.
With that in mind this Dunolly sample is zoomed in to roughly 1/4 of the area of the Signal Dunolly map. The old map focuses primarily on geology which I admit is always handy to have, but the reality is i'm not searching for gold 20' deep! What I am interested in is the lay of the land. I'll take modern contours/shading over that 1915 hand drawn scribble to indicate a hill any day!
I can see why that went out of fashion! 
What I do find interesting is the lack of attention to the diggings on the old geo maps, most probably because they were focused on professional mining and not metal detecting back in 1915. In most cases worked gullies are indicated by just a single dotted line, where as the Signal shallow workings actually look dramatically different. They vary in width, length, direction, location and quantity. I'm still convinced that Signal are the best resource for diggings data out there - nothing appears to be close.
Finally it's interesting to note that on this thread someone stated that Signal maps were too busy for them, while others have said that there isn't enough detail. It seems as though maps are a very personal thing! I actually like that. Life would be pretty boring if we were all the same
) so am somewhat familiar with both. First of all this is the same scenario as was discussed with the Kangaroo Flat sample. What's posted above is one of the few (as in 4 or 5) surveys that the state government carried out at that level of detail, which appears to be around the 1:10,000 mark. The hero goldfields surrounding the town centres of Castlemaine, Ballarat, Bendigo and Dunolly received this level attention, but no where else.
With that in mind this Dunolly sample is zoomed in to roughly 1/4 of the area of the Signal Dunolly map. The old map focuses primarily on geology which I admit is always handy to have, but the reality is i'm not searching for gold 20' deep! What I am interested in is the lay of the land. I'll take modern contours/shading over that 1915 hand drawn scribble to indicate a hill any day!
I can see why that went out of fashion! What I do find interesting is the lack of attention to the diggings on the old geo maps, most probably because they were focused on professional mining and not metal detecting back in 1915. In most cases worked gullies are indicated by just a single dotted line, where as the Signal shallow workings actually look dramatically different. They vary in width, length, direction, location and quantity. I'm still convinced that Signal are the best resource for diggings data out there - nothing appears to be close.
Finally it's interesting to note that on this thread someone stated that Signal maps were too busy for them, while others have said that there isn't enough detail. It seems as though maps are a very personal thing! I actually like that. Life would be pretty boring if we were all the same
I can imagine the swinging would have been good over one of those freshly deserted/logged goldfields back in the day too!
Last edited by a moderator:
It depends on your primary focus and geological knowledge (and I don't have the two maps side by side to compare so this is a generalization). Every one of the old maps I showed earlier had contours on them (as is common from the 1940s onward with the advent of aerial photography). Keep in mind that if you are GIS-trained it is easy to register an old map and then superimpose modern topographic contours on it.I have a Signal Dunolly map and a downloaded copy of that old geo map too (which i'd love to print, frame and stick on my wall one day!
First of all this is the same scenario as was discussed with the Kangaroo Flat sample. What's posted above is one of the few (as in 4 or 5) surveys that the state government carried out at that level of detail, which appears to be around the 1:10,000 mark. The hero goldfields surrounding the town centres of Castlemaine, Ballarat, Bendigo and Dunolly received this level attention, but no where else.
With that in mind this Dunolly sample is zoomed in to roughly 1/4 of the area of the Signal Dunolly map. The old map focuses primarily on geology which I admit is always handy to have, but the reality is i'm not searching for gold 20' deep! What I am interested in is the lay of the land. I'll take modern contours/shading over that 1915 hand drawn scribble to indicate a hill any day!
What I do find interesting is the lack of attention to the diggings on the old geo maps, most probably because they were focused on professional mining and not metal detecting back in 1915. In most cases worked gullies are indicated by just a single dotted line, where as the Signal shallow workings actually look dramatically different. They vary in width, length, direction, location and quantity. I'm still convinced that Signal are the best resource for diggings data out there - nothing appears to be close.
Finally it's interesting to note that on this thread someone stated that Signal maps were too busy for them, while others have said that there isn't enough detail. It seems as though maps are a very personal thing! I actually like that. Life would be pretty boring if we were all the same
Also, there are different types of Cenozoic (Tertiary) and Holocene sediments - shown here as 4 different groupings such as Pliocene and Recent - and the old maps give additional info as to what you can expect of any gold distribution (they can all look much the same in the field). But that is probably more than most people want - it increases chances of success, but in most cases people just want to get out there - and spend a lot of some days searching where there is unlikely to be any gold at all. Unfortunately it requires some geological understanding. For example, if you go back to my post #25, the 2nd (Gordon) and 3rd (Mt Egerton) map examples, they show Tpg (in yellow) and large areas of Qro. I would not personally waste a minute running my detector over any such areas (eg Tpg on these maps is probably sand from an old sea, unlikely to show any gold concentrations). But they look much like sand and gravel in the area deposited by ancient rivers, that do contain gold. It is one reason I favour detecting gold shed down hillsides from reefs, as WalnLiz describe (I can tell the differences between gravels but it really requires knowledge of the area you are in - e.g. those deposited in the sea tend to have well-rounded quartz pebbles and a polished, pearly look to pebbles - I think it was Hawkeye who posted an example).
I will give an example of application of the old maps - you have a broad area of green alluvium on the old Dunolly map with a dotted area shown within it.
Shafts do not indicate where gold occurred, they indicate where old-timers dug when looking for gold, which is not always the same thing. The gold was not in the "green" alluvium, it was in an older channel beneath it. The dots usually indicate that position - shafts not sunk on the dotted area were those not thought to have yielded gold (on this map positions of nuggets are shown I think, as well as depths to bedrock in feet). There was no point in showing shafts on the old maps (although most would have been on the actual lead positions once the old-timers got into slightly deeper ground). Often individual shafts were shown on old maps if deeper workings were present, as with "deep lead" shafts. but they were not good indicators of the lead position because they tended to be sunk off to one side of the lead, a drive being put towards the lead at depth).
So positions of recognizable shafts nowadays on modern maps can be meaningless (or worse, quite misleading) as to where the lead was at depth) - they are simply a feature of where a shaft can still be recognized, which may or may not have been a shaft correctly sunk on the lead. Claims were tiny - in shallow leads (the best ones to detect dumps on) you could almost jump the distance between shafts, so there was no point in the old-time geologists mapping them all. Most old shafts are often obliterated by dozing, ploughing and floods nowadays.
.
Last edited:
"go back to my post #25, the 2nd (Gordon) and 3rd (Mt Egerton) map examples, they show Tpg (in yellow) and large areas of Qro"
Tpg and Qro were new acronyms for me, so I downloaded those maps and I see the legend mentioning Tpg, but dont see Qro. I was wondering what you are referring to when you say Qro? Did you mean Qrc?
Last edited:
Yes, it was a typo
Hi Goldielocks,
Amazing. Thank you for your hugely insightful contributions to this forum. I’m a newbie here but I am trying to soak up as much as the information in your posts and comments as possible.
I was probably going to fall for the same trap as most people and start detecting in the Qrc areas which contain the 'shallow' leads (since learnt from you they go down to 30m), working my way downhill and (across the hill) towards the gullies from auriferous reefs marked on the map. Is that a bad approach?
Or would you suggest my time would be better spent searching the O and Dgr areas in the Gordon maps (and elsewhere) and in general is where one should focus attention detecting? It seems counterintuitive, as my understanding is the majority of alluvial gold in VIC existed in tertiary. However, you're suggesting (as we are armed with only the depth of a detector) that if we can find shallow areas of detritus sitting on top of O and Dgr, this is where a detector would be best served to prospect as the oldest gold deposits formed in the O and Dgr and these deposits are also the richest due to the long weathering events during the Paleogene and the alluvial gold trapped in the Tpg and Qrc areas are just too deep.
Last edited:
Firstly, shallow leads go to a MAXIMUM of about 30 m, deeper than which they are deep leads. Deeper than a few metres and it is only material around the shaft collar, brought up from depth, that is likely to contain gold. However the gold is present in leads BELOW the Qrc (the Qrc itself rarely contains gold except close to quartz reefs). So the old maps are useful to show the areas where the leads occurred beneath the Qrc, as often they are now bulldozed beyond recognition (often before the days of detectors). Nevertheless any gold at surface will be in material redistributed from around old shaft collars. Qrc is more commonly clay and fine sand, and gold in the underlying leads is in coarser sand and gravel in the main especially if pebbles are mostly white vein quartz. Often focusing on that difference helps. The leads themselves have sometimes been exposed at surface in their upper part (by erosion), where they tend to be fairly narrow channels in O (again white vein quartz helps). Those areas are ok, but they tend to dive to depth beneath Qrc farther down stream (i.e. down the palaeo stream that they formed in).
Tpg - I would not worry with in the area south from Scarsdale etc in central Victoria - they were mostly marine rocks and yielded no significant alluvial gold, but they can resemble the gravel and sand of true lead deposits farther north.
Dgr is granite from memory and almost always contained no gold in central Victoria (an exception was the fine gold at Mafeking, which was a poor mans diggings anyway). . Sometimes they contained gold that was derived from O but travelled away in streams that crossed the granite - since it was far from its source it was usually fine-grained but was occasionally quite payable (eg Woolshed). Usually granites are a complete waste of time and I never prospect there. This is NOT true in parts of NSW and Queensland.
O has gold of two types - (1) in and around quartz reefs (reef or primary gold) and (2) eluvial gold derived from them, in the soil downslope of reefs. This is really gold that travelled downslope under gravity but which did not make it as far as the leads (former gullies and creeks). Either of these, and the heads of old leads mentioned above, can also have been reworked by rain into modern shallow gullies on steep slopes, where it is a bit suck it and see (to see whether or not it has been sufficiently concentrated). Some were bonanzas in their extreme headwaters close to reefs, but rarely bonanzas at a distance of 500 m from reefs.
I guess the take-away message is that most Victorian alluvial gold, shallow or deep,was deposited in rivers perhaps 30 million years ago. That was why it took 18 years of settlement before the first major discoveries were made, because the leads rarely cropped out at surface. These old and dominant lead rocks are commonly called Renmark Group or on maps. A lot of gold came off hillsides in steep gullies in O (Ordovician) or as eluvial in its soil. All of these tend to have lots of white vein quartz pebbles associated with them. Only a small amount of Victoria's gold came from modern river beds and in the main was lower grade but larger volume (eg Lerderderg River bed, Yarra River bed, Ovens Valley). Some of these were dredged, as dredges or hydraulic sluices could put through large volumes of gravel cheaply so lower grades could be worked. Often miners diverted the river through tunnels to expose dry modern river gravels that they could work once drained, but in many cases returns were miserable (there were minor exceptions, eg around Beechworth, usually in higher river-gradient areas with steeper slopes where the river derived gold from older leads and reefs on its banks). These young river gravels tend to have far less white vein quartz pebbles but rock (not quartz) pebbles and cobbles dominate.
The above is true west from the Hume Highway in the main, to around Stawell and Ararat. Farther east alluvial gold was mostly much different (most leads were small and were in modern drainages, often with many rock cobbles as well as quartz cobbles, and nuggets were far less abundant.)
Last edited:
Reading your content is both thoroughly enjoyable and educational. Thank you so much for your response.
So it sounds like if goldierocks was to go detecting in central VIC goldfields, goldierocks wouldn't be running over the surface of the shallow lead areas shown on the maps, other than collars of the old shallow lead shafts (which are generally hard to see now, but can possibly be delineated via geovic) and potentially surrounding areas in search of some redistributed gold from the same.
1) Perhaps it is better to chase eluvial gold with a Z7? I would imagine exposed auriferous reefs would be the priority target areas (even though they have been worked). The idea being to work downhill and across the slope from exposed auriferous reefs, and into the modern gullies to find nuggets old timers a) were not looking for (in searching for the source) and b) didnt have detectors to 'stumble' upon during their loaming process. 2) I'm wondering if it would be possible to delineate (via geovic or similar) exposed auriferous reefs vs auriferous reefs at depth? 3) Is it worth searching for eluvial gold downhill of auriferous reefs that are at depth? I've noticed that the depth of reefs is not shown on geovic. Would depth of the reefs be a consideration in the hunt for eluvial gold? Perhaps its a matter of extrapolating data from the mines/shafts nearby.
Yes, on a few maps the dip of reefs is shown and one can calculate where they are at depth - but usually you would have to go to the old mine plans for the particular reef (which you can find on Geovic). However, reefs have to be exposed at surface to shed eluvial gold - what reefs do at depth is irrelevant (i.e your detector can only detect gold in reefs to such a shallow depth that it is of no help). Loaming did not help to locate individual nuggets in the main - they can still be there.
Thanks for clearing that up for me regarding reefs at depths. That’s great info. I see you use this term a lot, ‘in the main’. What do you mean by that?
Mean by what Geepeezee? Dip?
https://openpress.usask.ca/geolmanual/chapter/overview-of-strike-dip-and-structural-cross-sections/
I was about to research dip, thanks for that. These illustrations are really helpful.
But my question related to your use of the term “in the main”? What does this term mean?
Edit: never mind. I see it means “in general”. Haven’t heard it before
.
Last edited:
Yep, mostly...it is dinosaur languageI was about to research dip, thanks for that. These illustrations are really helpful.
But my question related to your use of the term “in the main”? What does this term mean?
Edit: never mind. I see it means “in general”. Haven’t heard it before
in general —used to say that a statement is true in most cases or at most times The workers are in the main very capable. The weather has in the main been quite good. “In the main.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/in the main.
Any planar geological feature has a strike and a dip.
Just a few thoughts to add into the discussion.
Note also how steep or shallow the ground is. The chances are that this rate of deepening will be reflected under the surface of the later sediments.
Gently sloping ground should theoretically give more width for detecting nuggets carried into the sediments.
I'd be looking not so much at the middle of sedimentary areas that can be many meters deep and certainly out of range of detectors but at the contact areas between the gold bearing sediments and the rocks which contained the gold reefs.
The inked or plotted contour lines on Geo maps can equate to a width of many meters on the ground and are often poorly defined. But I think that would be a good place to start looking.
Note also how steep or shallow the ground is. The chances are that this rate of deepening will be reflected under the surface of the later sediments.
Gently sloping ground should theoretically give more width for detecting nuggets carried into the sediments.
I'd be looking not so much at the middle of sedimentary areas that can be many meters deep and certainly out of range of detectors but at the contact areas between the gold bearing sediments and the rocks which contained the gold reefs.
The inked or plotted contour lines on Geo maps can equate to a width of many meters on the ground and are often poorly defined. But I think that would be a good place to start looking.
user 22230
Gavin of Garfield
- Joined
- Dec 7, 2021
- Messages
- 998
- Reaction score
- 2,681
But if you lived in the Golden Triangle area "in the main" would have a complete different meaning
In the main to a local would mean in Castlemaine 
You don't show the soil layer on the exposed slope, my main target. Your comment re hillslope under cover is true in higher topographic-relief areas, but falls down where hillslopes meet broad valleys - the topography typically flattens under cover there. That is because larger streams tend to migrate back and forward within their valley, forming a flatter surface with often thin alluvium. But well out of detector range.
But these are all generalizations.
"However, reefs have to be exposed at surface to shed eluvial gold"
1) Is there anyway to delineate exposed auriferous reefs on maps vs buried auriferous reefs?
2) In Geovic the layer "Geological lines and faults" does show "AURIFEROUS QUARTZ WORKED" as the "type" for such reefs however how to know if they were exposed at the surface? Would it be a matter of reading the Geological reports and/or mine reports for associated reefs? Or is there an easier/quicker way? As the way I describe above would have to be done reef by reef :/
3) Also, geovic shows reefs as "QUARTZ WORKED"? Why is it worked if its not auriferous? Or does a "QUARTZ WORKED" reef mean the old timers looked for gold but it wasnt there? Does "QUARTZ WORKED" definitely mean its not auriferous?
Essentially, trying to delineate "AURIFEROUS QUARTZ WORKED" (exposed) reefs using the maps and data we have at our disposal.
Wondering what would be the best way to go about that. Any ideas goldierocks?
Last edited:
(1) and (2) Nearly all marked reefs on maps were discovered because they were found at surface"However, reefs have to be exposed at surface to shed eluvial gold"
1) Is there anyway to delineate exposed auriferous reefs on maps vs buried auriferous reefs?
2) In Geovic the layer "Geological lines and faults" does show "AURIFEROUS QUARTZ WORKED" as the "type" for such reefs however how to know if they were exposed at the surface? Would it be a matter of reading the Geological reports and/or mine reports for associated reefs? Or is there an easier/quicker way? As the way I describe above would have to be done reef by reef :/
3) Also, geovic shows reefs as "QUARTZ WORKED"? Why is it worked if its not auriferous? Or does a "QUARTZ WORKED" reef mean the old timers looked for gold but it wasnt there? Does "QUARTZ WORKED" definitely mean its not auriferous?
Essentially, trying to delineate "AURIFEROUS QUARTZ WORKED" (exposed) reefs using the maps and data we have at our disposal.
Wondering what would be the best way to go about that. Any ideas goldierocks?
(3) it means it WAS worked for gold - so the opposite.
Last line - essentially what you see marked is what was discovered in the past. Fortunately it ain't rocket science.
So don't overthink it, select an area, select a line of reefs, detect in the soil downslope. Gold found in the end is proportional to the time spent swinging more than time spent thinking. However the basics that I have outlined will increase your chances tenfold over not swinging in a correct area.
Last edited:
(1) and (2) Nearly all marked reefs on maps were discovered because they were found at surface
(3) it means it WAS worked for gold - so the opposite.
Last line - essentially what you see marked is what was discovered in the past. Fortunately it ain't rocket science.
So don't overthink it, select an area, select a line of reefs, detect in the soil downslope. Gold found in the end is proportional to the time spent swinging more than time spent thinking. However the basics that I have outlined will increase your chances tenfold over not swinging in a correct area.
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?
Similar threads
