23 oz. to the ton


Recommended Posts

Hello all,

I am new to the forum here. I am from BC Canada and am highly interested in detecting for gold.I recently posted this on a couple of other forums as I would love as many opinions as possible. So if you have already read this I apologize.

I am currently playing around a bit with a GMT but am awaiting a Minelab. My interests are purely in eluvial or residual hillside deposits. I have a question for you all. Up here in BC we don't seem to have too too many detecting enthusiasts like down south so I have had a hard time getting a good answer that relates specifically to detecting for gold.

My question is directed towards practical research in locating an area with good potential patches or even the odd piece of quartz and gold mix. In my research I have come across many interesting load deposit locations that get my interest. In particular I am wondering what the minimal oz. to the ton or oz. to the gram load would be reasonable to start detecting below the outcrop would be?

I have one that is running 23oz. of free milling gold to the ton of material. In your opinion would a grade like this produce visible nugget gold or even the od chunk of quartz float with nugget sized gold? Many load sources here in BC and I suspect down South often will grade what seems to be fairly low but the creek below has had a history of largish nuggets. As an example a load with a grade of 1 gram to the ton. Would this be worth detecting below?I have heard that even some of these low grade hardrock deposits will contain glory holes. Some of that material could have been at the surface and eroded away and left only a low grade deposit behind. Is this a smart way of looking at things?

As a poll and to get the members opinions what would your minimum grade of gold to the ton or gram be before it would catch your attention enough to take a trip 3 hrs away or more to swing for the day on the slope below. I am very, very curious about your opinions on this.

Any thoughts would be greatly appreciated.

Thanks again.

Link to comment
Share on other sites

I don't know that there is an exact answer to your question. 23 ounce to the ton is pretty rich stuff. I mean you can theorize that because you are getting so much free milling gold, that the deposit is the remnants on gold that was widely disseminated throughout the host rock until it was liberated, and because it was distributed in minute form, there just was not any large veins.

We have several mines in the Nelson Mining area that produced millions of dollars worth of gold, and the host rock was monzonite. None of this gold was visible, and there is no gold that is detectable with a metal detector in the area.

When you are finding 1 grammers, I would think that there is a better than average chance that there are bigger nuggets deeper.

The other theory may be that the free milling gold you are finding is just the fines from a larger placer deposit "up the hill." The theory is always that the larger gold stays closer to the source.

When you're getting 23 ounces to the ton, I would say worrying about where the bigger nuggets are is a delightful way to spend your time. I believe that' s what we call a good problem.

Good Luck and BCOT!

Doc

Link to comment
Share on other sites

  • Admin

Hello BCprospector,

Having a Geology background I will give you my thoughts. Having 23 ounces to the ton can mean several things. First, you need to find out if that was taken from the highgrade ore or the average ore. Typically ore bodies have rich sections called "ore chutes," which can be very rich, much richer than the typical run the mill ore. If you take a sample from the highgrade you will get a really high "ounce per ton" ratio. I'm seen some chutes run as high as 100 ounce per ton, but there is very little tonage to process.

You're highgrade ore might run 23 ounce per ton, but you're overall ore might only be 1/4 - 1/2 per ton, which is mineable in some locations.

If you're searching for gold nuggets, I would make sure the ore is "free milling" and "pockety" ore. These types of ore bodies or veins will produce 99% of your gold nuggets that are found today near the surface.

Someone also mentioned the top sections of the vein are the richest. Well they might not be the richest, but weathering (physical and chemical) has taken place and removed (most of the time lower) towards the water table leaving free milling ore that can be crushed or roasted to extract the precious metals.

Most of the other impurities and metal can weather down further near the water table creating a "secondary enrichment."

This will give you some ideas on what to look for. There is a bunch I didn't cover.

Take care,

Rob Allison

Link to comment
Share on other sites

Hello BCprospector,

Having a Geology background I will give you my thoughts. Having 23 ounces to the ton can mean several things. First, you need to find out if that was taken from the highgrade ore or the average ore. Typically ore bodies have rich sections called "ore chutes," which can be very rich, much richer than the typical run the mill ore. If you take a sample from the highgrade you will get a really high "ounce per ton" ratio. I'm seen some chutes run as high as 100 ounce per ton, but there is very little tonage to process.

You're highgrade ore might run 23 ounce per ton, but you're overall ore might only be 1/4 - 1/2 per ton, which is mineable in some locations.

If you're searching for gold nuggets, I would make sure the ore is "free milling" and "pockety" ore. These types of ore bodies or veins will produce 99% of your gold nuggets that are found today near the surface.

Someone also mentioned the top sections of the vein are the richest. Well they might not be the richest, but weathering (physical and chemical) has taken place and removed (most of the time lower) towards the water table leaving free milling ore that can be crushed or roasted to extract the precious metals.

Most of the other impurities and metal can weather down further near the water table creating a "secondary enrichment."

This will give you some ideas on what to look for. There is a bunch I didn't cover.

Take care,

Rob Allison

Wow great info guys. This is narrowing this down for me for sure. I need to think about this a bit before I can properly reply back top this. I have a few more questions. Thanks again!!! You guys really know your stuff.

Link to comment
Share on other sites

  • Admin

Hey BC,

You're very welcome. Continue to ask questions as we all learn from these type of threads. You might consider scanning any mine dumps or tailings with a high freq. VLF metal detector to see what they might have missed. For the most part, all gold bearing mines discarded some good ore.

I would also scan below any exposed vein if you can ID it.

Wishing you the best,

Rob Allison

Link to comment
Share on other sites

Ok well I know you guys can't discuss this topic forever as there are way too many variables! But what are some word indicators to show that the ore is not free milling. Sulphides deposit might not be the place to start a search below for a patch right?

Free milling can cover alot so if the gold is associated with quartz does this usually mean free milling?

And if there was a gully below this out crop but it was rather steep but in a dry deserty area would you think there could be float still hung up on the hillside?

Thanks again guys!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share