Geological Maps - information and questions

[mbasko]

Think BB nailed it. :Y:

I had a look at Geoview & the area I zoomed in on came up with these too:
A-b-PRK; Rocklea Inlier greenstones; Basaltic and andesitic flows, and associated volcaniclastic rocks; metamorphosed
A-b-PYV; Sylvania Inlier greenstones; Mafic volcanic rocks; metamorphosed
A-b-PWY; Wyloo Inlier greenstones; Basaltic and andesitic flows, and associated volcaniclastic rocks; metamorphosed
That's what I was thinking with the localised formations/groups. A NSW Geo map I looked at had used lettering aa, aab, aam etc. in the key/legend for localised formations/groups.

Yes, but a is probably not Archean in NSW - unfortunately there is not complete standardisation,

Yeah it wasn't Archean in NSW just the abbreviated lettering in the key/legend got me thinking it may have been used in a similar way for local formations/groups.
It would be good if there were some type of standardisation for us mug punters.
A big golden arrow or X would be good :lol:

 

[shakergt]

A= Archaean
b= Basalt, includes doleritic layers and lenses
is it good for gold? well your in the greenstone, thats a start

Thank you spoon. That is what I was after. For some reason I am not able to find a map legend for geology view in tengraph. From what you are saying I take it the ground I'm looking at is laterite over greenstone = possible gold

Yes, I agree - it narrows it down a bit. If the area is a past gold-producer as well, you are in a good place. There is hardly any gold at all in granite in WA, so avoid granite areas.

My bad guys. I took greenstone literally. I did not realize it is a general term for granite. Defently no gold to be found in granite that's for sure.

 

[user 4386]

Think BB nailed it. :Y:

I had a look at Geoview & the area I zoomed in on came up with these too:
A-b-PRK; Rocklea Inlier greenstones; Basaltic and andesitic flows, and associated volcaniclastic rocks; metamorphosed
A-b-PYV; Sylvania Inlier greenstones; Mafic volcanic rocks; metamorphosed
A-b-PWY; Wyloo Inlier greenstones; Basaltic and andesitic flows, and associated volcaniclastic rocks; metamorphosed
That's what I was thinking with the localised formations/groups. A NSW Geo map I looked at had used lettering aa, aab, aam etc. in the key/legend for localised formations/groups.

Yes, but a is probably not Archean in NSW - unfortunately there is not complete standardisation,

Yeah it wasn't Archean in NSW just the abbreviated lettering in the key/legend got me thinking it may have been used in a similar way for local formations/groups.
It would be good if there were some type of standardisation for us mug punters.
A big golden arrow or X would be good :lol:

It would be useful for us geos too - you only have to do it part-time! AGSO is trying to standardize.

 

[user 4386]

A= Archaean
b= Basalt, includes doleritic layers and lenses
is it good for gold? well your in the greenstone, thats a start

Thank you spoon. That is what I was after. For some reason I am not able to find a map legend for geology view in tengraph. From what you are saying I take it the ground I'm looking at is laterite over greenstone = possible gold

Yes, I agree - it narrows it down a bit. If the area is a past gold-producer as well, you are in a good place. There is hardly any gold at all in granite in WA, so avoid granite areas.

My bad guys. I took greenstone literally. I did not realize it is a general term for granite. Defently no gold to be found in granite that's for sure.

No, greenstone is not a name for granite - it is used for greenish rocks that used to be basalt lavas etc. They are pretty good for gold. I was simply warning you to avoid granite areas in general. The accuracy of a map varies with scale and the geo who maps it does not walk all the ground (most is done by remote sensing followed by ground checking of key areas). So you often find unmapped patches of granite inside areas shown as greenstone (in some areas anyway), so just walk over them without wasting time - focus on the greenstone. Banded iron formation can also be an important host for gold (eg Hill 50 mine at Mt Magnet).

Gold can occur in granite elsewhere in Australia (some major mines), but it is extremely rare in the Eastern Goldfields.

 

[Goldchaser1]

A= Archaean
b= Basalt, includes doleritic layers and lenses
is it good for gold? well your in the greenstone, thats a start

Thank you spoon. That is what I was after. For some reason I am not able to find a map legend for geology view in tengraph. From what you are saying I take it the ground I'm looking at is laterite over greenstone = possible gold

Yes, I agree - it narrows it down a bit. If the area is a past gold-producer as well, you are in a good place. There is hardly any gold at all in granite in WA, so avoid granite areas.

My bad guys. I took greenstone literally. I did not realize it is a general term for granite. Defently no gold to be found in granite that's for sure.

Dont discount areas with granite shaker,some good areas it wont be far away,i hate the stuff and usually run away as fast as i can but ive seen a couple of spots where its found amongst it,some rich areas will have it as a contact more or less i think,goldirocks is right about the eastern goldfields id say but up north ive seen deposits amongst it,one that stands out is the western edge of tamboura in the pilbara and down at reedys sth of meeka theres a alot of granite about,and like goldirocks mentions i know a couple of good areas in the eastern goldfields where it just pops up amongst the greenstones and laterite,looks quite out of place and not very inviting goldwise......

 

[shakergt]

A= Archaean
b= Basalt, includes doleritic layers and lenses
is it good for gold? well your in the greenstone, thats a start

Thank you spoon. That is what I was after. For some reason I am not able to find a map legend for geology view in tengraph. From what you are saying I take it the ground I'm looking at is laterite over greenstone = possible gold

Yes, I agree - it narrows it down a bit. If the area is a past gold-producer as well, you are in a good place. There is hardly any gold at all in granite in WA, so avoid granite areas.

My bad guys. I took greenstone literally. I did not realize it is a general term for granite. Defently no gold to be found in granite that's for sure.

Dont discount areas with granite shaker,some good areas it wont be far away,i hate the stuff and usually run away as fast as i can but ive seen a couple of spots where its found amongst it,some rich areas will have it as a contact more or less i think,goldirocks is right about the eastern goldfields id say but up north ive seen deposits amongst it,one that stands out is the western edge of tamboura in the pilbara and down at reedys sth of meeka theres a alot of granite about,and like goldirocks mentions i know a couple of good areas in the eastern goldfields where it just pops up amongst the greenstones and laterite,looks quite out of place and not very inviting goldwise......

Interesting info Goldchaser1. I know that the area I am heading to has produced good gold and that there is plenty of greenstone, quartz and ironstone about. Hopefully it comes up with the goods. If I travel all that way and find some well its a bonus. If I come home empty handed I will not be to disappointed about it. At least I will get some time with the family when we are away.

 

[shakergt]

Thank you all who have replied to this thread. Your information has been really helpful and because of your information I have now noticed a nice band of banded iron on the map that I missed before. This might be one of my target areas now.

 

[Goldchaser1]

Hope ya have a good trip shaker,wed like to see ya come back with enough to park a phase 3 in the shed.....

 

[shakergt]

That would be nice. Even enough for a ESP XD or XE would be enough also. First things first though enough to go towards a new detector would be good. A GPX 4500, 4800 or 5000 would do me nicely or even a 7000. Here's hoping.

 

[Ded Driver]

A= Archaean
b= Basalt, includes doleritic layers and lenses
is it good for gold? well your in the greenstone, thats a start

Thank you spoon. That is what I was after. For some reason I am not able to find a map legend for geology view in tengraph. From what you are saying I take it the ground I'm looking at is laterite over greenstone = possible gold

Yes, I agree - it narrows it down a bit. If the area is a past gold-producer as well, you are in a good place. There is hardly any gold at all in granite in WA, so avoid granite areas.

My bad guys. I took greenstone literally. I did not realize it is a general term for granite. Defently no gold to be found in granite that's for sure.

hey Shakergt, my old man was working a bulldozer on construction of the Margaret River Dam back in the 90's & brought home some granite slabs that had wafer thin gold scattered thru it. We didn't crush it, but rather used it as a feature in his garden (they were big slabs, 2 guys couldn't carry them so they weren't going anywhere). The gold was so thin we figured it would be more effort than warranted to try & extract any gold from it.

 

[user 4386]

A= Archaean
b= Basalt, includes doleritic layers and lenses
is it good for gold? well your in the greenstone, thats a start

Thank you spoon. That is what I was after. For some reason I am not able to find a map legend for geology view in tengraph. From what you are saying I take it the ground I'm looking at is laterite over greenstone = possible gold

Yes, I agree - it narrows it down a bit. If the area is a past gold-producer as well, you are in a good place. There is hardly any gold at all in granite in WA, so avoid granite areas.

My bad guys. I took greenstone literally. I did not realize it is a general term for granite. Defently no gold to be found in granite that's for sure.

hey Shakergt, my old man was working a bulldozer on construction of the Margaret River Dam back in the 90's & brought home some granite slabs that had wafer thin gold scattered thru it. We didn't crush it, but rather used it as a feature in his garden (they were big slabs, 2 guys couldn't carry them so they weren't going anywhere). The gold was so thin we figured it would be more effort than warranted to try & extract any gold from it.

My great great great grandpa apparently discovered the Margaret River goldfield (Thomas Moriarty).

 

[Ded Driver]

Goldierocks ...... heir to riches! haha, bugger its in such hard rock & not in great quantities. That & we aren't permitted to prospect in state forest these days.

 

[user 4386]

Think BB nailed it. :Y:

I had a look at Geoview & the area I zoomed in on came up with these too:
A-b-PRK; Rocklea Inlier greenstones; Basaltic and andesitic flows, and associated volcaniclastic rocks; metamorphosed
A-b-PYV; Sylvania Inlier greenstones; Mafic volcanic rocks; metamorphosed
A-b-PWY; Wyloo Inlier greenstones; Basaltic and andesitic flows, and associated volcaniclastic rocks; metamorphosed
That's what I was thinking with the localised formations/groups. A NSW Geo map I looked at had used lettering aa, aab, aam etc. in the key/legend for localised formations/groups.

Yes, but a is probably not Archean in NSW - unfortunately there is not complete standardisation,

Yeah it wasn't Archean in NSW just the abbreviated lettering in the key/legend got me thinking it may have been used in a similar way for local formations/groups.
It would be good if there were some type of standardisation for us mug punters.
A big golden arrow or X would be good :lol:

I'm a bit unclear as to why people don't use the maps that show the locations of gold mines for each state to narrow down areas of interest.

 

[mbasko]

Comment was tongue in cheek. I'd reckon most do use the gold mine location maps etc. but a lot also research virgin areas too - prospecting.

 

[user 4386]

Comment was tongue in cheek. I'd reckon most do use the gold mine location maps etc. but a lot also research virgin areas too - prospecting.

Good for you! Many of our present major mines were in virtually insignificant goldfields until the 1970s and 1980s - Telfer, Boddington, Cloncurry region (old goldfield but completely new and distant and major areas), Olympic Dam area, Henty, Challenger. Some in the Gascoyne....

 

[shakergt]

Comment was tongue in cheek. I'd reckon most do use the gold mine location maps etc. but a lot also research virgin areas too - prospecting.

Good for you! Many of our present major mines were in virtually insignificant goldfields until the 1970s and 1980s - Telfer, Boddington, Cloncurry region (old goldfield but completely new and distant and major areas), Olympic Dam area, Henty, Challenger. Some in the Gascoyne....

That's what I have been using for my research. There is so much virgin ground out there if you are prepared to travel for it. The area I am heading has only been operating since the late 1990s so it could be possible to find virgin ground.

 

[shakergt]

I know that CZL ground can produce gold and also CZL over AI is good but can any one enlighten me on CZL over Ag? Is that a good sign and also does anyone know what Qa represents on a geology map?

 

[Goldchaser1]

Ag by memory should be granite shaker,czl bordering granites is a good thing,worth a look,Qa is the alluvials i think,as in flats,can be alot of quartz covered flats etc,Au is another to keep an eye out for-ultramafics,ironstones etc.....
Ai im not sure on.....
Im no expert,i just use the basics then time on the ground if it looks good,also theres lots of pockets out there not mapped,found a few spots that show nothing on a 250k geo map.....

 

[kingswood]

I know that CZL ground can produce gold and also CZL over AI is good but can any one enlighten me on CZL over Ag? Is that a good sign and also does anyone know what Qa represents on a geology map?

Qa is alluvium- sand, silt and gravel in drainage lines and flood planes.
Ag is undivided granitoid.

 

[shakergt]

Ag by memory should be granite shaker,czl bordering granites is a good thing,worth a look,Qa is the alluvials i think,as in flats,can be alot of quartz covered flats etc,Au is another to keep an eye out for-ultramafics,ironstones etc.....
Ai im not sure on.....
Im no expert,i just use the basics then time on the ground if it looks good,also theres lots of pockets out there not mapped,found a few spots that show nothing on a 250k geo map.....

Maybe worth a look then as the area I am looking at is in the southern goldfields of WA