How conductive is the soil where you live? A series of maps...

[BarnacleBill]

of various parts of the world. The maps for VLF, that is 30kHz and below are the first ones numbered 1 thru 6.

On the U.S. map, the Great Salt Lake sticks out like a sore thumb with a figure of 4,000 mS/m the same as the oceans.


http://www.qsl.net/on4baa/mirror/antennas/VLF%20&%20MF%20Conductivity%20Atlas.pdf

HH
BarnacleBill

 

[cymro]

Thanks B.B. very interesting post.
Dave

 

[Digger]

which happens to represent the value of my soil conductivity level. Wish I lived elsewhere....... I could have given a higher mark. HH Randy

 

[Doug[Manila]]

Hi BB,.
What do the numbers mean? it is 10 where i live.
Thanks for sharing

 

[howlow666]

Well seems I llive in a 10 zone as well. Now is that a bad thing, and how bad if so ? Funny thats around about the number my XT 70 gives me most places. I wonder if bill could shed a little more light on this for us. Well good luck HH L8R.


Jay

 

[BarnacleBill]

I have done some limited experimenting with studying both the conductive & magnetic components of soil, but I I know 1% with 99% more to be explored.

The following is an experiment I did some time ago that may be instructive:

http://www.findmall.com/read.php?55,571764,571764#msg-571764

But even that experiment leaves a conundrum. It is pretty widely reported anecdotally that after heavy rains that coins are found deeper. Most suggestions of the cause I have seen point to various salts going into solution as the underlying cause for the increase in depth. Therefore if you take that as a premise then the more saline your soil the more of that effect you may see. There also seems to be a feeling that multi-freqs & PI's can get targets deeper on saltwater beaches than inland.

However the flip side of the coin would seem to be that wet saline soil, though allowing coins to be detected deeper, might also enhance the magnetic mineral noise signal by better coupling the current to the minerals in the soil. And that's the part I haven't quite taken on yet to try to figure out. Maybe those Ozzies that are burrowing holes into the sides of dry wash banks to test the big PI coils might have some data. But we would need data for VLF's to have it pertain to the X-Terra line.

HH
BarnacleBill

 

[TURNMASTER]

I am in eastern Washington and it looks to vary from a 10 to a 3 depending on where you are north to south, but mostly 3. I seem to come away from the map thinking that I can expect more chatter and a harder time overall with the 10. Now please keep in mind that I am a newbee and am prone to make false assertations about metal detector settings and behavior.

I know that the ground conditions vary, but does more conductivity mean that I can hit a gold nugget at greater depth or does it signal that I may find more problems and have more dificulty setting up my machine. The latter would be oddly soothing to me as it seems to be taking me longer than I think it should to learn to set up my machine when hunting for coins. I have not gone prospecting yet but will soon.

Bill, this seemed to be a simple and educational post at first, then I realized I don't know how to use the data even if I can read the data. Oh crud my Knickers are all twisted up now, I think we are solidly a 3 here in Spokane, but still how should a guy apply the data?

Thanks
Jeff

 

[mooser]

I live in a 1 zone, is there a prize for this.After looking at all this stuff, i still do not know nothing from nothing.

 

[SteveP(NH)]

Hey Bill,

I always thought that one got more depth after it rained just because water itself is a good conductor and so wet soil will conduct signals better than dry soil. It seems to me that at least in some parts of the country with low minerialization that the salt component of soil whether it is in solution or not would be a minor constituent of the soil and so would have a small effect compared to other factors.

It seems like this would fit experience as wet soil (away from salt water beaches) doesn't become more difficult to detect in due to falsing or rapidly changing ground values like sand at salt water beaches does so it would seem like practical experience confirms that dissolved salts don't play a big part when detecting in wet soil with low mineralization.